Ashford University - PSY 635; Week 4 Quiz, Latest 2019/20 Complete Guide. PSY 635 Week 4 Quiz 1. A person through whom a researcher gains access to a group, community, or organization is known as a(n) _____. 2. A defining feature of _____ is that this method always aims to uncover previously unquestioned assumptions about the nature of the world and reality and to consider the possible consequences of these assumptions. 3. Discourse analysis is a _____ approach, which means that it works on the premise that the use of language allows people to negotiate meanings and bring concepts into reality. 4. Using more than one method to verify findings is called _____. 5. Grounded theory studies often use a sampling strategy that continues to develop throughout the analysis, which is called _____. 6. A characteristic of _____ is resistance to pre-existing knowledge. 7. Qualitative researchers use _____ to capture ideas, interpretations, and responses to the data during the study. 8. Grounded theory uses data collection techniques from another qualitative research method, _____. 9. The sampling strategy in which the researcher recruits people who are easy to reach is called _____. 10. The _____ approach to narrative analysis uses rich descriptions of people in their accustomed surroundings.

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Devry University MGMT 597 Week 8 Final Exam (Version 3) Page: 1 (Essay Questions) Question (TCO A, C) Kenneth hired a real estate agent named Barbara to sell a condominium he owned in New York. The asking price for the modest two-bedroom unit was $1,300,000. Kenneth told Barbara he would go as low as $1,100,000, but no lower, but that she should try to get as high a price as possible. If he couldn’t get that much for it, he said he would use it as rental property. A good friend of Barbara’s was in the market for a two-bedroom condominium in New York. In fact, this friend had come to Barbara to help her find a place and negotiate for it. Barbara’s friend said that she could absolutely not spend more than $1,000,000. When Kenneth hired Barbara to sell his condominium, Barbara told her friend about it and the asking price. Barbara told her friend, “Don’t even bother…….. Barbara then proposed to her friend that they go in together, with Barbara fronting some money through her friend, but not having Barbara’s name on the contract as purchaser. Before they could work out the details, Barbara’s friend received a raise and decided to buy the condominium. Barbara negotiated a price of $1,100,000 on Kenneth’s behalf. Kenneth later found out that Barbara had told her friend about his bottom price, and about the plan for Barbara to help buy the house. What claims, if any, does Kenneth have? (Points : 50) Question (TCO B, D) At Super Car Outlet, Joan was negotiating with Marge for the purchase of a used car. Marge told Joan that she would fix any problems with the drivetrain that arose in the first 1,000 miles. After further negotiation, they signed a written agreement that provided that the sale was made “as is, without any warranties.” After driving the car for 400 miles, the antilock brake system failed. Marge denied having made the repair promise. But she said she would cover $200 of the repair costs. Joan then took the car ….. repaired at a cost of $487. Joan now wants to recover the full repair costs from Marge. Marge refuses to pay any amount. Discuss the issues that would arise in this case. (Points : 50) Question (TCO E, H) Determine whether the following instrument is a negotiable instrument, addressing all the requirements of negotiability in your response. I, James Wyatt, promise to pay $12,000 to Buck’s Bikes in four equal installments of principal, beginning on January 1, 2011, and on the same day in each of the next three years. Each payment will consist of $3,000 in principal, plus interest accrued since the date of this note, in the case of the first payment, or since the prior payment in the case of all other payments…….. This note is secured by collateral consisting of various machines. This note may ….. paid in whole or in part prior to the due dates, and the interest accrued will …. reduced accordingly. The due date for any payment under this note …… extended by mutual agreement of the parties up to six months from the due date as stated herein. The proceeds of this note will …. used by James Wyatt to further his experiments, and in the event those experiments are unsuccessful, the payment obligation is canceled. (Points : 50) Page: 2 (Essay Questions) Question (TCO F, G) Little Oil is an oil-drilling company that has defaulted on several of its loans. Giantoil Oil Refining is owed $230,000 on a loan that is secured by some of Little Oil’s drilling equipment. This equipment is worth around $180,000. Giantoil has repossessed the equipment pursuant to its security agreement and has notified Little Oil that it proposes to keep the equipment rather than sell it. Little Oil does not want Giantoil to keep the equipment and wants it to …. sold. Discuss the legal issues in this situation. (Points : 50) Question (TCO C, D, G) Fred is a director of the ALLSTAR Corporation, which is engaged in the business of creating and marketing toys and games. A proposal is made to the board to manufacture and market a toy bird that really flies. Market surveys have ….. done to indicate that the toy would be a good seller, and engineering studies have ….. done testing the feasibility of such a product. Fred reviews this information and votes in favor of producing this new toy. The vote was 7 to 4 in favor. ALLSTAR produces and markets this new toy bird, but sales are very slow. After several years of losing money, ALLSTAR discontinues this toy. Tina, a shareholder of ALLSTAR, thinks the toy bird venture was a waste of time and money. In fact, she thinks the idea was so bad that she sues Fred for breach of his fiduciary duty of due care in making the decision to proceed with the bird. Discuss the general standards …….. in this situation.(Points : 50) Question (TCO D, H) Mark is a CPA in a large city who audited the financial statements of a firm that sold specialized computer equipment around the world. This was a complex audit, and Mark prepared numerous working papers in connection with the audit. Mark also had numerous conversations with client personnel in his efforts to understand the complex transactions and accounts. Mark’s client has recently become the subject of an investigation for numerous violations of law. Charges will soon …….. subject to a subpoena? (Points : 50)

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Prof. James Lindahl Phil 160 Lecture Notes Compiled Here are compiled lecture notes for Prof. James Lindahl Phil160 class at SJSU from the beginning of the semester to the end.

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Chamberlain College Of Nursing Week 1 Social Causes of Suicide-SOCS 185 Required Resources Read/review the following resources for this activity: Textbook: Chapter 1 Lesson Minimum of 3 outside scholarly sources Instructions The textbook reading for the week explores social forces that can affect the seemingly private act of suicide. For this assignment, conduct scholarly research on a different private or individualistic act that could be regarded as a broader social problem or social issue, something other than suicide. You may choose one of the following or a topic of your own: Homelessness Veteran homelessness Domestic violence Addiction Obesity In an essay, address the following: Determine how the sociological imagination can help understand that problem. Compare and contrast that research with the textbook\'s explanation of ways sociologists apply the sociological imagination to understand a problem. Your paper must contain scholarly support in the form of quotes or paraphrases with respective citations from assigned reading (the textbook/lesson) and the outside scholarly sources that you identify on your own. Writing Requirements (APA format) Length: 2-3 pages (not including references page) 1-inch margins Double spaced 12-point Times New Roman font Running header in the upper left of all pages Page number in the upper right of all pages Parenthetical in-text citations included and formatted in APA style References page (minimum of 3 outside scholarly sources plus the textbook/lesson)

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SOUTH UNIVERSITY-NSG 6430 APEA Exam GI (Question and Answers)ALREADY GRADED A A patient with diarrhea is tested for C. difficile. How soon should the enzyme immunoassay (EIA) yield results? Older adults frequently complain of constipation. Which medication listed below does NOT increase the likelihood of constipation in an older adult? A 79-year-old with an appendicitis is unlikely to exhibit A 10-year-old female presents with a 3-month history of abdominal pain. She has been diagnosed with recurrent abdominal pain. During the interview the nurse practitioner is likely to elicit a finding of A patient with gall bladder disease has classic symptoms. Which symptom below is NOT classic of gallbladder disease? A 24-year-old male has recently returned from a weekend camping trip with friends. He has ulcerative colitis and history of migraine headaches. He reports a 2-day history of headache, nausea, and vomiting with weakness. Which of the following is not part of the differential diagnosis A 45-year-old patient has the following laboratory values. HBsAg positive; anti-HBc positive; anti-HBs negative. How should they be interpreted? This patient has a positive hepatitis B surface antigen (HBsAg). Therefore, he has hepatitis B. A positive anti-HBc is …in patients who either have hepatitis now or who have had it. The surface antibody (anti-HBs) would be …..to be negative in a patient with positive surface antigen (HBsAg) because these two markers will not be positive at the same time. What medication …..below could be ….to increase appetite in an anorexic patient? A patient is in the clinic with a 36- hour history of diarrhea and moderate dehydration. Interventions should include: A 56-year-old male patient has been …..with an inguinal hernia. What symptom would make the nurse practitioner suspect an incarcerated hernia? A patient asks for advice about a medication that will produce rapid relief if he is having heartburn symptoms. What should the nurse practitioner recommend? A patient has a positive hepatitis B surface antibody. This means he: An 83-year-old patient is diagnosed with diverticulitis. Where is her pain typically located? Many older adults have cachexia. What characterizes this? Lovely, an 84-year-old, complains of fecal incontinence. A likely cause is: A 40-year-old patient has the following laboratory values. How should they be interpreted? HBsAg negative; anti-HBs positive; anti-HBc negat A 40-year-old patient has the following laboratory values. HbsAg negative; Anti-HBc positive; anti-HBs positive. How should they be interpreted? A patient has hepatitis B. He probably has a predominance of: Which medication listed below can exacerbate the symptoms of GERD? Which description is more typical of a patient with acute cholecystitis? GERD (gastroesophageal reflux disease) and physiologic reflux have similar characteristics. However, physiologic reflux: The three most common causes of bacterial diarrhea in the US are Salmonella, Campylobacter, and: A 95-year-old male has lost muscle mass as he has aged. He does not have any underlying disease that has caused this loss. What is this termed? A 37-year-old has routine blood work performed during an annual exam. On exam he has a tender, enlarged liver. How should the nurse practitioner proceed? A 70-year-old patient states that he had some bright red blood on the toilet tissue this morning after a bowel movement. He denies pain. What is the LEAST likely cause in this patient? A 70-year-old presents to the nurse practitioner’s office for a well exam today. What medication probably has no effect on screening for occult blood in the stool? Which symptom is INCONSISTENT with irritable bowel syndrome in older adults? A 19-year-old female presents with a temp of 100.8°F and lower abdominal pain that began about 12 hours ago. She denies vaginal discharge. Which choice below is the least likely cause of her symptoms? An 83-year-old patient is diagnosed with diverticulitis. The most common complaint is: The relationship between duodenal ulcer disease and H. pylori infection is: A 24-year-old female presents with pain and tenderness in the right lower abdominal quadrant. Her pelvic exam and urinalysis are within normal limits. Her WBC is elevated and her urine pregnancy test is negative. What is part of the differential diagnosis? The most common reason that older adults develop peptic ulcer disease is: Most patients who have acute hepatitis B infection: A 26-year-old female presents with concerns about possible hepatitis C (HCV) infection. She admits to IV drug use 2 months ago and sharing needles with several other people. Initial laboratory studies have been completed. Anti-HCV reactive. How should this be managed? A patient has been diagnosed with hepatitis B. The most common reported risk factor is nsg 6430 apea exam What medication used to treat patients who have GERD provides the fastest relief of heartburn symptoms? Symptoms of uncomplicated reflux disease in older adults should be treated: A 26-year-old female complains of pain at McBurney’s point. She feels nauseated. Her vital signs are provided. The most appropriate initial action by the NP is to: A 48-year-old patient has the following laboratory values. Anti-HCV reactive; HCV RNA detectable. How should they be interpreted? A 3-day-old full-term infant has a bilirubin level of 16 mg/dL. How should this be managed? A 6-week-old male infant is brought to the nurse practitioner because of vomiting. The mother describes vomiting after feeding and feeling a “knot” in his abdomen especially after he vomits. The child appears adequately nourished. What is the likely etiology? A patient has suspected peptic ulcer disease. Her symptoms occur a few hours after eating. She probably has a(n): Which patient has the least worrisome symptoms associated with his diarrhea? One with: A 5-year-old female’s playmate has been diagnosed with pinworms. The mother brings her child in for an exam. The 5 year-old denies rectal itching. How should the NP proceed? A 35-year-old patient has the following laboratory values. HBsAg negative; anti-HBc negative; anti-HBs negative. How should they be interpreted? An 84-year-old presents with a stated involuntary weight loss. He states that he’s lost about 6 pounds in the last 6 or 8 weeks. What statement below is NOT part of the assessment? Most patients who have acute hepatitis A infection: An older patient presents with left lower quadrant pain. If diverticulitis is suspected, how should the NP proceed? A 7-year-old male presents with encopresis. The NP might expect nsg 6430 apea exam The initial step in the management of encopresis is: Choose the number on the image that most closely approximates the location of a direct inguinal hernia. The most common place for indirect inguinal hernias to develop is: What is the simplest screen for nutritional adequacy in elderly patients? Which of the following is an appropriate initial intervention for gastroesophageal reflux disease (GERD) in an 8-week-old? A 42-year-old patient was diagnosed with ulcerative colitis many years ago. What part of his routine health screenings should be stressed by the nurse practitioner? A patient presents with complaints of bright red stools over the past week. This symptom could be consistent with: A 63-year-old male has been your patient for several years. He is a former smoker who takes simvastatin, ramipril, and an aspirin daily. His blood pressure and lipids are well controlled. He presents to your clinic with complaints of fatigue and “just not feeling well” for the last few days. His vital signs and exam are normal, but his liver enzymes are elevated. His hepatitis panel is negative for infectious hepatitis. What is the most likely cause of his elevated liver enzymes? A 20-year-old female patient presents with tenderness at McBurney’s point. Appendicitis is considered. What laboratory test should be done initially to determine the etiology of this patient’s abdominal pain? A patient has the following laboratory value. Anti-HAV IgG positive. What is the clinical interpretation? The most common place for indirect inguinal hernias to develop is: What is the simplest screen for nutritional adequacy in elderly patients? A 31-year-old patient is suspected of having hepatitis C. He reports possible exposure about a month ago. How should the nurse practitioner interpret his laboratory results? Anti-HCV nonreactive; HCV RNA not detectable. A fecal occult blood test (FOBT) obtained during a rectal examination: A healthcare provider (“the HCP”) was stuck with a needle from a patient ….to be ….with HIV (“the patient”). A rapid HIV test was …..on the patient and found to be positive. This means that: A 50-year-old with a history of consumption of 3-4 alcoholic drinks daily and weekend binges has elevated liver enzymes. Which set of enzymes is most representative of this patient? Which imaging study of the abdomen would be LEAST helpful in diagnosing an acute appendicitis? Hirschsprung’s disease is characterized by: A mother of a 4-week-old infant visits your office. She states that her baby is vomiting after feeding and then cries as if he is hungry again. What should the nurse practitioner assess? Which choice contains three medications that should have liver function tests measured prior to initiation of the medications? A patient has been …..with viral gastroenteritis. He has nausea and vomiting, and has started having lower abdominal cramps. What is the most effective intervention for him? A 5-year-old has been …..with pinworms. He lives with his mother. There are no other members of the household. How should his mother be managed? An older adult has suspected vitamin B12 deficiency. Which of the following lab indices is more indicative of a vitamin B12 deficiency? What is true regarding older adults who are overweight nsg 6430 apea exam Children with an inguinal hernia: An 85-year-old adult has chronic constipation. What is the most likely cause of her constipation? The relationship between colon polyps and colon cancer is that polyps Which of the following is NOT a risk factor for developing hepatitis B? A patient has had right upper quadrant pain that has lasted for the past 3 days, but the pain has become acute in the past 12 hours. He has low-grade fever. Which lab test(s) will be …..if he has pancreatitis? An 85-year-old adult has chronic constipation. How should this be managed initially? Which term does not characterize hemorrhoids? Choose the number on the image that most closely approximates the location of an indirect inguinal hernia nsg 6430 apea exam A 43-year-old female patient reports a possible exposure to hepatitis C about 4 months ago.HBsAg negative; Anti-HBc Negative; Anti-HBs positive; anti-HCV nonreactive; HCV RNA not detectable. Which statement is true about this patient? Which is NOT an effective strategy for helping older adults gain weight? A patient has received a prescriptions for metronidazole for treatment of C. difficile. What should be avoid in this patient? A patient has been ….with hepatitis A. The most common ….risk factor is: What choice below is most commonly ….with pancreatitis? The early signs and symptoms of appendicitis in an adult sg 6430 pea exam The most common symptoms associated with gastroesophageal reflux disease (GERD) are heartburn and: Which of the following symptoms is typical of GERD? A patient presents with right upper quadrant and upper abdominal pain. Acute cholecystitis is …..because the pain radiates to the: A patient with a ….inguinal hernia should be examine: What medication may be …..to treat GERD if a patient has tried over-the-counter ranitidine without benefit? The two tests that can indicate current infection with hepatitis B are: The most common cause of diarrhea in adults is: A patient has elevated liver enzymes. What is the likely etiology of the elevation? A patient has the following lab results. This means nsg 6430 apea exam A 14 year-old male patient has an acute, painless groin swelling. Which tool would yield the most information to identify the etiology of the swelling? A 15-year-old is about 10% below her ideal body weight. Laboratory studies were……. Which complaint might be common in this patient? A patient has the following lab values. HBsAg negative; anti-HBc negative; anti-HBs positive. This indicates that he: A patient has the following laboratory values. HBsAg Positive; IgM anti-HBc positive. What does this mean? An inguinal hernia is …..on a male patient by an examiner. Which word below best describes what the hernia feels like when touched by the examiner? A 20-year-old female patient presents with tenderness at McBurney’s point. What laboratory test supports a diagnosis of appendicitis? A patient has the following laboratory values. Anti-HAV IgM Negative; AntiHAV IgG negative. What does this mean?

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NURS6521 MIDTERM EXAM ANSWERS (Advanced Pharmacology) NURS6521 MIDTERM EXAM ANSWERS (Advanced Pharmacology)

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NURS6521 Week 3 quiz with answers NURS6521 Week 3 quiz with answers

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Liberty University BUSI 342 Discussion Board 3 thread paper writing solution Topic: Choose a pay for performance method from the following categories: Individual, Group, or Organizational performance and use the Internet to locate the website of a company which has recently introduced a new pay system. Then assess from the information, the drivers that were making the change necessary for the company, the steps and rationale of the system, implementation steps they utilized, and their results. Be sure to provide any URLs you used as a reference source for your answer.

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Liberty University BUSI 352 quiz 3 complete solutions correct answers A+ work Liberty University BUSI 352 quiz 3 complete solutions correct answers A work

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University of La Verne BIOL 101 quiz 3 questions and answers Graded A Latest University of La Verne BIOL 101 quiz 3 questions and answers Graded A Latest

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Liberty University BIOL 101 Quiz 3 / Liberty University BIOL101 Quiz 3 (3 Latest Versions)(Already graded A) Liberty University BIOL 101 Quiz 3 / Liberty University BIOL101 Quiz 3 (3 Latest Versions)(Already graded A)

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Walden University - NURS 6630 > NURS 6630 Final Exam Test (2020), Verified Clean A. Walden University - NURS 6630 > NURS 6630 Final Exam Test (2020), Verified Clean A.

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WALDEN UNIVERSITY.GRADE A.NURS 6541 Week 9 Quiz 1 – Question and Answers WALDEN UNIVERSITY.GRADE A.NURS 6541 Week 9 Quiz 1 – Question and Answers

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WALDEN UNIVERSITY GRADED A-NURS 6541 Week 11 Quiz – Question and Answers WALDEN UNIVERSITY GRADED A-NURS 6541 Week 11 Quiz – Question and Answers

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Chapter 36: Bacteremia and Sepsis. Answers Explained Chapter 36: Bacteremia and Sepsis Test Bank MULTIPLE CHOICE 1. Which of the following is an example of a primary bacteremia source? a. An infected heart valve b. A case of pneumonia c. A patient with hepatitis d. A wound abscess A Bacteremia may be classified by its site of origin. Primary bacteremia arises from an endovascular source, such as an infected cardiac valve or an infected intravenous catheter, whereas secondary bacteremia arises from an infected extravascular source, such as the lung in patients with pneumonia; a case in which the source of bacteremia remains undefined is termed bacteremia of unknown origin. REF: 869 OBJ: Level 2: Interpretation 2. Which of the following is an example of a secondary bacteremia source? a. An infected cardiac valve b. The lung c. An infected intravenous catheter d. The bone marrow B Bacteremia may be classified by its site of origin. Primary bacteremia arises from an endovascular source, such as an infected cardiac valve or an infected intravenous catheter, whereas secondary bacteremia arises from an infected extravascular source, such as the lung in patients with pneumonia; a case in which the source of bacteremia remains undefined is termed bacteremia of unknown origin. REF: 870 OBJ: Level 2: Interpretation 3. Bacteremias can be classified by all of the following categories except: a. microbiology. b. acquisition. c. pathogenesis. d. duration. C Bacteremias can be classified by microbiology, acquisition, and duration. REF: 870 OBJ: Level 1: Recall 4. What condition results when there is a procedural manipulation of a body site containing normal flora, causing those bacteria to enter the bloodstream? a. Continuous bacteremia b. Intermittent bacteremia c. Septic shock d. Transient bacteremia D Transient bacteremia usually occurs after a procedural manipulation of a particular body site that is colonized by indigenous flora, causing the organisms to enter the blood. Such sites include the mouth, and the gastrointestinal and urogenital tracts. Transient bacteremia may appear for a brief period following dental, colonoscopic, or cystoscopic procedures. REF: 870 OBJ: Level 1: Recall 5. What is the most common clinical manifestation associated with continuous bacteremia? a. Meningitis b. Pleurisy c. Encephalitis d. Endocarditis D Infective endocarditis is the most common clinical manifestation associated with continuous bacteremia, although other endovascular sources, such as infected intravascular catheters or septic thrombi, can result in continuous bacteremia. REF: 870 OBJ: Level 1: Recall 6. All of the following factors are associated with an unfavorable outcome in bacteremia except: a. surface wound or abscess. b. polymicrobial bacteremia. c. presence of malignancy. d. acquired immunodeficiency syndrome (AIDS). A Factors associated with an unfavorable outcome in bacteremia include age older than 70 years; polymicrobial bacteremia; presence of malignancy; AIDS or renal failure; origin of the bacteremia in the respiratory tract, bowel; unknown origin; and inappropriate antimicrobial therapy. REF: 870 OBJ: Level 1: Recall 7. Bacteremias are least often associated with which of the following patient conditions? a. Patients with hematologic malignancies b. Those undergoing elective outpatient surgical procedures c. Those receiving immunosuppressive chemotherapy d. Patients undergoing bone marrow transplantation B Bacteremias are more frequent among persons with neoplasia, especially those with hematologic malignancies, those receiving immunosuppressive chemotherapy, and those undergoing bone marrow transplantation. REF: 871 OBJ: Level 1: Recall 8. Which immunosuppressive agent can increase a patient’s risk of bacteremia? a. Cancer chemotherapy b. Corticosteroid therapy c. Transplant maintenance therapy d. All of the above D Bacteremias are more frequent among persons with neoplasia (abnormal growth of new cells that may be benign or malignant), especially those with hematologic malignancies, those receiving immunosuppressive medication or chemotherapy, and those undergoing bone marrow transplantation. Persons with other chronic underlying diseases (e.g., diabetes, cirrhosis) and those receiving immunosuppressive therapy (e.g., those receiving glucocorticoids for rheumatoid arthritis, stem cell or solid organ transplant patients) are also at increased risk for bacteremia. REF: 871 OBJ: Level 1: Recall 9. What underlying condition predisposes a person to a polymicrobial bacteremia? a. Intravenous drug use b. Burns c. Gastrointestinal tract sources d. All of the above D The predisposing factors in polymicrobial bacteremia include intravenous drug use, burns, and gastrointestinal tract sources. Especially at risk are immunocompromised patients, particularly those with alcoholism, granulocytopenia, extensive burns, diabetes mellitus, and chronic renal failure, and patients with vascular insufficiency as a result of ischemia. REF: 872 OBJ: Level 1: Recall 10. Development of a vaccine has decreased which major cause of bacteremia in children? a. Haemophilus influenzae b. Streptococcus pneumoniae c. Escherichia coli d. Hepatitis A A Some organisms have become less prevalent causes of bacteremia because of immunization practices that have decreased the risk of infection. For example, infection with H. influenzae b, formerly a major cause of bacteremia and sepsis in children, decreased by over 95% after introduction of the conjugate Hib vaccine. REF: 872 OBJ: Level 1: Recall 11. The patient’s immune system attempts to control infection via which of the following mechanisms? a. Antibodies b. Complement activation c. Phagocytosis d. All of the above D Once bacteremia occurs, the patient’s immune system attempts to control infection via antibodies, which opsonize organisms and allow complement-mediated killing, as well as by phagocytosis. In addition, filtering mechanisms in the lymphatics and large vascular beds in the liver and spleen may sequester organisms and allow their destruction. REF: 872 OBJ: Level 1: Recall 12. Bacteremia with which organism often leads to endocarditis, osteomyelitis, septic arthritis, hepatic abscess, or pyomyositis? a. Streptococcus pneumoniae b. Escherichia coli c. Staphylococcus aureus d. Pseudomonas aeruginosa C S. aureus is particularly prone to cause metastatic infection or abscess formation as a consequence of bacteremia; S. aureus bacteremia may lead to endocarditis, osteomyelitis, septic arthritis, hepatic abscess, or pyomyositis. REF: 872 OBJ: Level 2: Interpretation 13. What are two potential consequences of bacteremia? a. Endocarditis and meningitis b. Meningitis and encephalitis c. Encephalitis and hepatitis d. Sepsis and septic shock D Sepsis and septic shock are potential consequences of bacteremia. REF: 872 OBJ: Level 1: Recall 14. Lipopolysaccharide in gram-negative bacteria and the lipoteichoic acid and peptidoglycan in gram-positive bacteria cause which of the following to be released in the human body? a. Tumor necrosis factor b. Interleukin (IL)-1 c. IL-6 d. All of the above D In both cases, a bacterial membrane component (lipopolysaccharide, also known as endotoxin, in the case of gram-negative organisms; lipoteichoic acid and peptidoglycan in the case of gram-positive organisms) interacts with macrophages and causes release of tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6, and other proinflammatory cytokines, increasing endothelial activation, vascular permeability, blood flow, and recruitment of neutrophils. REF: 872 OBJ: Level 2: Interpretation 15. The most common sites associated with bacteremia and sepsis include all the following except: a. reproductive organs. b. infected intravascular catheters. c. the lung. d. the abdomen. A A number of sources often give rise to bacteremia. The most common sites associated with bacteremia and sepsis are infected intravascular catheters, the urinary tract, the lung, and the abdomen. REF: 873 OBJ: Level 1: Recall 16. All of the following organisms are colonizers of indwelling catheters except: a. coagulase-negative staphylococci. b. Streptococcus pyogenes. c. Staphylococcus aureus. d. Enterococcus spp. B As useful as indwelling catheters are, they are highly vulnerable to colonization and infection by organisms, such as coagulase-negative staphylococci, S. aureus, and Enterococcus spp., with subsequent spread to the bloodstream to cause bacteremia; frequently, the strains causing a catheter-related bloodstream infection are resistant to multiple antibiotics. REF: 871 OBJ: Level 1: Recall 17. How does a biofilm protect the organism from host defenses? a. By inhibiting phagocytosis b. By inhibiting chemotaxis c. By suppressing the lymphoproliferative response d. All of the above D The biofilm protects the organism from host defenses by inhibiting phagocytosis, chemotaxis, and oxidative metabolism and by suppressing the lymphoproliferative response. It may also significantly increase the concentrations of antimicrobials required to inhibit the growth of coagulase negative staphylococci attached to the catheter. REF: 873 OBJ: Level 1: Recall 18. What organism is most commonly associated with bacteremia due to acute pyelonephritis? a. Escherichia coli b. Enterobacter aerogenes c. Pseudomonas aeruginosa d. Staphylococcus aureus A Urinary tract infections account for roughly 17% of all bacteremias. Infection of the upper urinary tract (acute pyelonephritis) leads to bacteremia in up to 40% of affected patients. E. coli is the most common cause of bacteremia in this setting. REF: 873 OBJ: Level 1: Recall 19. All of the following organisms are common causes of pneumonia and which typically produce a concurrent bacteremia except: a. Enterobacter aerogenes. b. Escherichia coli. c. Pseudomonas aeruginosa. d. Staphylococcus aureus. B The most common organisms in pneumonia that produce a concurrent bacteremia include S. pneumonia, H. influenzae, S. aureus, P. aeruginosa, and Enterobacter aerogenes. REF: 873 OBJ: Level 1: Recall 20. What condition leads to most (75%) of the cases of bacteremia arising from intra-abdominal infections? a. Pleurisy b. Cholecystitis c. Peritonitis d. Irritable bowel syndrome C Primary peritonitis, which frequently occurs in patients with cirrhosis, is associated with bacteremia in 75% of cases involving aerobic bacteria; common pathogens include Escherichia coli, Klebsiella pneumoniae, Streptococcus pneumoniae, and Enterococcus. REF: 873 OBJ: Level 1: Recall 21. What can happen when a transient bacteremia is produced from a dental procedure or a superficial skin infection? a. Hepatitis can result. b. Pneumonia can result. c. Deep vein thrombosis can result. d. Cardiac valves can be seeded with bacteria. D Transient bacteremia (from dental procedures or a superficial skin infection) can seed cardiac valves with bacteria. These organisms multiply within a dense vegetation composed of bacteria and fibrin, protected from killing by neutrophils, and give rise to a continuous bacteremia, which can then seed other organs. REF: 874 OBJ: Level 2: Interpretation 22. What type of a medical implant device is commonly associated with osteomyelitis, which will then lead to bacteremia? a. Prosthetic joints b. Stainless steel rods c. Orthopedic screws d. Orthopedic plates A Prosthetic joints, particularly those implanted in the hip, can be hematogenously seeded by organisms, such as Staphylococcus aureus and coagulase-negative staphylococcus, and then give rise to bacteremia. REF: 874 OBJ: Level 2: Interpretation 23. Abnormal conditions that may indicate the presence of bacteremia include all the following except: a. disseminated intravascular coagulation (DIC). b. thrombocytopenia. c. coagulopathy. d. anemia. D Altered clinical laboratory values that may be indicative of bacteremia include the following: thrombocytopenia, leukocytosis or leukopenia, lactic acidosis, hypoglycemia or hyperglycemia, abnormal liver function tests, coagulopathy, DIC, and elevations in C-reactive protein, haptoglobin, and fibrinogen. REF: 874 OBJ: Level 1: Recall 24. When drawing blood for blood cultures in a child younger than age 10, how much blood should be drawn? a. 1 mL for each year of life b. 5 mL c. 2 mL d. 1 mL for children younger than 2 years old, 3 mL for children younger than 7 years old, and 5 mL for children up to 10 years old A The following age-volume protocol has been recommended: younger than age 10, 1 mL of blood for each year of life; 10 years old or older, 20 mL; and 10 years old or older (poor veins), less than 20 mL. This protocol is based on studies that have demonstrated that as the volume of blood cultured increases from 2 to 20 mL, the yield of positive culture results increases from 30% to 50%, except in newborns. REF: 875 OBJ: Level 1: Recall 25. The recommendation of three sets of blood culture drawn at 1-hour intervals is recommended to diagnose which of the following conditions? a. Meningitis b. Infective endocarditis c. Pneumonia d. Peritonitis B Arbitrary timing of 30- to 60-minute intervals between draws has shown no significant differences in positivity rates, therefore blood culture sets may be obtained simultaneously or consecutively as long as they are from separate venipunctures. The exception is for suspected infective endocarditis in which 30- to 60-minute intervals are recommended to document continuous bacteremia. REF: 876 OBJ: Level 2: Interpretation 26. If a patient with a bacteremia is receiving appropriate antibiotics for a known infection but is not responding to treatment, how does the physician find out if another organism is causing the problem? a. Redraw the blood cultures. b. Redraw the blood cultures using an antibiotic removal device (ARD). c. Switch the patient to another antibiotic that will resolve the clinical symptoms. d. Perform hemodialysis to remove the organisms from the patient’s blood. B In specimens from patients receiving clinical amounts of -lactam antimicrobial agents, penicillinase may be added to the medium to inactivate these agents. Some commercially available automated blood culture systems have blood culture bottles containing ARD, a resin that nonspecifically absorbs any antimicrobial agent present in the patient’s blood. REF: 877 OBJ: Level 2: Interpretation 27. SPS performs all the following functions in the blood culture bottles except: a. anticoagulation. b. prevention of phagocytosis. c. act as a bacterial nutrient. d. inactivate certain antibiotics. C SPS, one of the commonly used additives, performs the following functions: anticoagulation, neutralization of the bactericidal effect of human serum, prevention of phagocytosis, and inactivation of certain antimicrobial agents. REF: 877 OBJ: Level 2: Interpretation 28. Septi-Chek is which type of blood culture system? a. Continuous-monitoring blood culture system b. Lysis-centrifugation blood culture system c. Aerobic-anaerobic blood culture system d. Biphasic broth-slide system D A broth-slide system was designed from the original biphasic blood culture medium culture bottle. Septi-Chek consists of a slide paddle containing chocolate, MacConkey, and malt extract agars attached to the top of a standard broth bottle. Once these bottles have been inoculated, they should be tipped daily or at least twice weekly so as to bathe the slide paddle with the broth culture medium. REF: 877 OBJ: Level 1: Recall 29. What is the principle of a continuous monitoring blood culture system? a. The amount of 14CO2 produced is measured as a growth index and compared with a threshold. b. The amount of increased lipopolysaccharide is measured and compared against the null value. c. The pH of the media is continuously measured to check for bacterial metabolic by-products. d. An optical monitor records the number of bacteria and records the growth. A When the organism in the blood culture bottle uses 14CO2-labeled substrate, 14CO2 is released. The instrument monitors CO2 production by aspirating gas into an ionization chamber using sterile needles. In the ionization chamber, the amount of 14CO2 produced is measured as growth index and compared with an established threshold level. REF: 878 OBJ: Level 1: Recall 30. How long are conventional (manually processed) blood cultures held before being discarded as negative? a. 4 days b. 7 days c. 14 days d. 21 days B Blood culture bottles are incubated at 35° 2° C for 5 days typically for the automated systems and may be held for 7 days for the manual systems. REF: 877 OBJ: Level 1: Recall 31. Separate venipunctures were performed to collect three sets of blood cultures from a patient with an artificial heart valve. The first and third sets grew a gram-positive pleomorphic rod in 1 of 2 bottles while the second set had no growth in either bottle. What is the most likely explanation for these findings? a. The patient probably has an infection with Clostridium spp. b. The blood cultures were contaminated with skin flora. c. The blood cultures were probably contaminated in the laboratory. d. The patient probably has an infection with Bacillus spp. B It is important to remember that even though antiseptic technique is used in the collection of blood, somewhere between 1% and 3% of blood cultures become contaminated with organisms such as coagulase-negative staphylococci, Corynebacterium spp., Bacillus spp. (not B. anthracis), alpha-hemolytic streptococci, and Propionibacterium acnes, which are ordinarily skin colonizers, resulting in pseudobacteremia. REF: 874 OBJ: Level 3: Synthesis 32. A patient receiving chemotherapy for leukemia has developed a fever causing the physician to request blood cultures times three. Each set of cultures grows an -hemolytic streptococcal organism? What is the most likely explanation for these results? a. The patient probably has an infection with -hemolytic strep. b. The blood cultures were contaminated with skin flora c. The blood cultures were probably contaminated in the laboratory. d. The patient probably has an infection with Bacillus spp. A In some patients, such as those receiving cancer chemotherapy, organisms such as coagulase-negative staphylococci, Corynebacterium spp., Bacillus spp. (not B. anthracis), -hemolytic streptococci, and Propionibacterium acnes, can represent true pathogens, making it essential to distinguish between blood culture results that reflect true bacteremia and those that represent pseudobacteremia. REF: 874 OBJ: Level 3: Synthesis 33. Which of the following organisms are inhibited by the anticoagulant sodium polyanethole sulfonate (SPS)? a. Enterobacter aerogenes b. Escherichia coli c. Peptostreptococcus anaerobius d. Streptococcus pyogenes C Despite its usefulness in blood culture media, SPS inhibits the growth of certain organisms, notably Peptostreptococcus anaerobius, Neisseria gonorrhoeae, N. meningitidis, and Gardnerella vaginalis. If these organisms are suspected, 1.2% gelatin added to the blood culture bottle may help to neutralize the inhibitory effect of SPS. REF: 877 OBJ: Level 3: Synthesis

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Chapter 35: Infections of the Central Nervous System. Answers Explained Chapter 35: Infections of the Central Nervous System Test Bank MULTIPLE CHOICE 1. What is the volume of cerebrospinal fluid (CSF) in an average adult? a. 90 to 150 mL b. 15 to 45 mL c. 40 to 80 mL d. 200 to 300 mL A In normal adults, the CSF volume ranges from 90 to 150 mL, the protein level is 15 to 45 mg/dL, and the CSF glucose level is 40 to 80 mg/dL (CSF glucose:serum glucose ratio of 0.6). REF: 856 OBJ: Level 1: Recall 2. All of the following organisms commonly cause meningitis except: a. Streptococcus pneumoniae. b. Pseudomonas aeruginosa. c. Haemophilus influenzae. d. Neisseria meningitidis. B Acute meningitis is commonly caused by bacteria (e.g., S. pneumoniae, N. meningitidis, H. influenzae), or viruses (e.g., enteroviruses, herpes virus, mumps virus). REF: 856 OBJ: Level 1: Recall 3. A college student is examined at the emergency department; he is disoriented with a fever, intense headache, stiff neck, vomiting, and sensitivity to light. His friends say that he has been sick for about 2 days and that his condition worsened over the last 3 hours. The physician does a complete blood count (CBC) and electrolytes. The electrolytes are normal, but the patient’s white blood count (WBC) is 12,000 cells/L. What test should the physician order next? a. Urinalysis and urine culture b. Stool Gram stain and culture c. Cerebrospinal fluid Gram stain and culture d. Blood cultures  3 C Patients with acute meningitis usually present with fever, headache, vomiting, photophobia, and altered mental status. REF: 856 OBJ: Level 3: Synthesis 4. What is the first step in developing meningitis? a. A cold that compromises your immune system b. Living in close quarters, like military barracks or a college dorm c. Poor sanitary conditions d. Nasopharyngeal colonization by a meningeal pathogen D The first step in the development of a meningeal infection with bacteria involves nasopharyngeal colonization by one of the meningeal pathogens, followed by local invasion across the mucosal barrier and entry into the bloodstream. REF: 856 OBJ: Level 1: Recall 5. What organism is the most common cause of meningitis in adults? a. Streptococcus pneumoniae b. Pseudomonas aeruginosa c. Haemophilus influenzae d. Neisseria meningitidis A S. pneumoniae is a gram-positive diplococcus and is the most common cause of meningitis in adults and the second most common cause of meningitis in children. REF: 857 OBJ: Level 1: Recall 6. What organism is a common cause of meningitis in neonates and infants up to 3 months of age and can be contracted by passing through the birth canal? a. Streptococcus pneumoniae b. Streptococcus agalactiae c. Haemophilus influenzae d. Neisseria meningitidis B S. agalactiae or group B streptococcus is a gram-positive coccus that is often isolated from rectal or vaginal cultures of asymptomatic pregnant women. It is a common cause of meningitis in neonates and infants up to age 3 months. REF: 857 OBJ: Level 2: Interpretation 7. What condition is characterized by lymphocytic pleocytosis in the cerebrospinal fluid (CSF) but a lack of identifiable organism after routine culture and Gram stain? a. Purulent meningitis b. Septic meningitis c. Aseptic meningitis d. Malignant meningitis C Viruses are the most common cause of aseptic meningitis, a condition characterized by a lymphocytic pleocytosis in the CSF and lack of identifiable etiologic agent after routine stains and culture of the CSF. REF: 858 OBJ: Level 2: Interpretation 8. All the following viruses can resist inactivation by gastric acid except: a. enteroviruses. b. adenoviruses. c. parvovirus. d. herpesvirus. D Some viruses, such as enteroviruses, adenoviruses, and parvovirus, can resist inactivation by gastric acid. After initial replication at the site of mucosal colonization, viremia develops, followed by invasion of the central nervous system (CNS). REF: 858 OBJ: Level 1: Recall 9. What enterovirus is commonly associated with neurologic illness? a. Coxsackievirus B b. Parvovirus c. Herpesvirus 1 d. Calicivirus A A Enteroviruses (EVs) belong to the family Picornaviridae and include the polioviruses, coxsackieviruses A and B, echoviruses, and the newly numbered EVs. The EVs that are frequently associated with neurologic illness include coxsackievirus B and echoviruses. REF: 858 OBJ: Level 1: Recall 10. What type of meningitis is usually uncomplicated and resolves in 2 to 7 days? a. Septic meningitis b. Enteroviral c. Bacterial d. Meningococcal B Most cases of enteroviral meningitis are uncomplicated, with signs and symptoms resolving in 2 to 7 days. REF: 859 OBJ: Level 2: Interpretation 11. Common arborviruses that cause meningitis include all the following except: a. St. Louis encephalitis virus. b. La Crosse virus. c. Venezuelan equine encephalitis. d. West Nile virus. C Although several of these viruses cause encephalitis, aseptic meningitis and meningoencephalitis can also occur. The common arboviruses causing aseptic meningitis include St. Louis encephalitis virus, La Crosse virus, eastern and western equine encephalitis virus, and West Nile virus. REF: 859 OBJ: Level 1: Recall 12. What is a common neurologic complication with the mumps? a. Encephalitis b. Meningoencephalitis c. Viremia d. Aseptic meningitis D The mumps virus, a member of the family Paramyxoviridae, is an RNA virus that commonly causes parotitis. Aseptic meningitis is the most common neurologic complication. REF: 859 OBJ: Level 1: Recall 13. What virus is an uncommon cause of aseptic meningitis that can be acquired from dust or food contaminated with urine or feces from infected rodents and hamsters? a. Lymphocytic choriomeningitis virus b. Epstein-Barr virus c. Guillain-Barré virus d. Astrovirus A Lymphocytic choriomeningitis virus is a member of the Arenaviridae family. It is an RNA virus that is an uncommon cause of aseptic meningitis in humans. The virus is shed in the urine and other excretions of infected rodents and hamsters. Humans are infected by aerosol or by ingestion of dust or food contaminated with the urine, feces, blood, or nasopharyngeal secretions of infected rodents. REF: 859 OBJ: Level 2: Interpretation 14. Syphilitic involvement in the central nervous system (CNS) can take all of the following forms except: a. syphilitic meningitis. b. aseptic meningitis. c. gummatous neurosyphilis. d. parenchymatous neurosyphilis. B Syphilitic involvement of the CNS can take one of four forms: syphilitic meningitis, meningovascular syphilis, parenchymatous neurosyphilis, and gummatous neurosyphilis. REF: 860 OBJ: Level 1: Recall 15. All of the following are common fungal causes of central nervous system (CNS) infection except: a. Cryptococcus neoformans. b. Coccidioides immitis. c. Candida albicans. d. Histoplasma capsulatum. C Fungi are rare causes of CNS infections. The most common organisms in CNS fungal infections include C. neoformans, C. immitis, H. capsulatum, and Blastomyces dermatitidis. REF: 860 OBJ: Level 1: Recall 16. What fungus causes chronic meningitis in HIV patients? a. Cryptococcus neoformans b. Coccidioides immitis c. Candida albicans d. Histoplasma capsulatum A C. neoformans is an encapsulated basidiomycetous yeast. It can spread hematogenously to the central nervous system (CNS) from pulmonary foci and can cause chronic meningitis, particularly in patients with acquired immunodeficiency syndrome (AIDS). REF: 860 OBJ: Level 1: Recall 17. A teenager and her friends go to the lake and spend the day swimming and picnicking. Later that evening, she starts to feel sick. She complains of a headache and general malaise. The next morning, she is very ill and is rushed to the emergency department. Many neurologic changes are noted. Despite the staff’s best efforts, the teenager dies. Autopsy reveals the presence of small protozoans in her brain tissue. What is the most probable organism that caused her death? a. Acanthamoeba spp. b. Naegleria fowleri c. Balamuthia mandrillaris d. Angiostrongylus cantonensis B N. fowleri can cause a rapidly progressive and almost always fatal primary meningoencephalitis. It is found in warm fresh water and moist soil. Most cases of infection have been associated with swimming in warm natural bodies of water. Acanthamoeba spp. and B. mandrillaris usually cause granulomatous amebic encephalitis with a more insidious onset. REF: 861 OBJ: Level 3: Synthesis 18. Infection with what organism results in a chronic meningoencephalitis, more commonly known as sleeping sickness? a. Gnathostoma spinigerum b. Baylisascaris procyonis c. Trypanosoma brucei d. Trypanosoma cruzi C Trypanosomes that infect humans include Trypanosoma brucei subsp. gambiense, Trypanosoma brucei subsp. rhodesiense, and Trypanosoma cruzi. The first two are found predominantly in Africa. Humans are infected by the bite of tsetse flies. T. brucei gambiense results in a more chronic and slowly progressing form of sleeping sickness compared to T. brucei rhodesiense, which has a more rapid and acute course. Both diseases are fatal if untreated. REF: 862 OBJ: Level 2: Interpretation 19. All of the following are common causes of viral encephalitis except: a. herpes viruses. b. enteroviruses. c. arboviruses. d. toroviruses. D The most common causes of encephalitis are viruses including herpes viruses, enteroviruses, and arboviruses. REF: 862 OBJ: Level 1: Recall 20. All of the following are important arboviruses except: a. alphaviruses (Venezuelan equine encephalitis viruses, eastern equine encephalitis, and western equine encephalitis). b. St. Louis encephalitis virus. c. La Crosse virus. d. Lassa fever virus. D Arboviruses (arthropod-borne viruses) are RNA viruses that demonstrate strong tropism for the central nervous system. These viruses are transmitted to humans by mosquitoes, ticks, or sandflies. Important arboviruses in the western hemisphere include members of the alphaviruses (eastern equine encephalitis, western equine encephalitis, and Venezuelan equine encephalitis viruses), flaviviruses (St. Louis encephalitis virus), bunyaviruses (La Crosse virus), and Coltivirus (Colorado tick fever). REF: 862 OBJ: Level 1: Recall 21. What virus, spread by the mosquito, causes a typically self-limiting illness, but can be associated with a rash, aseptic meningitis, myelitis, and fatal encephalitis? a. West Nile virus b. Eastern equine encephalitis c. Colorado tick fever d. Venezuelan equine encephalitis A West Nile virus (WNV) is a mosquito-borne flavivirus that commonly causes a self-limited febrile illness, often associated with a rash. In 1999 the virus was introduced in the United States; it has since spread rapidly. Neurologic involvement includes aseptic meningitis, myelitis, and fatal encephalitis. The mortality rate is about 5%, and death occurs mainly in older patients. REF: 863 OBJ: Level 2: Interpretation 22. A farmer is bitten by a raccoon. He takes the usual precautions and washes the wound with soap and water, and then puts a bandage on it. A couple of days later, he begins to feel tired, has an upset stomach, and the wound is painful. About 2 days after noticing the symptoms, the farmer begins to feel agitated. He has a seizure and hallucinations. What condition matches the farmer’s symptoms and history? a. West Nile virus b. Rabies c. Colorado tick fever d. Lassa fever B Infection with rabies occurs following bites from infected animals, such as skunks, raccoons, bats, and foxes, as well as domesticated animals, such as dogs. Initial symptoms include fatigue, gastrointestinal symptoms, and pain at the bite wound. Rabies can present as acute encephalitis indistinguishable from other viral encephalitides or with the classic syndrome of agitation, emotional liability, seizures, and hallucinations (furious rabies). REF: 863 OBJ: Level 3: Synthesis 23. From where do most cerebral abscesses spread? a. Middle ear infections b. Mastoiditis c. Paranasal sinus infections d. All of the above D The majority of cerebral abscess occur because of spread from a contiguous focus of infection in the middle ear, mastoid cells, or paranasal sinuses. REF: 863 OBJ: Level 1: Recall 24. What are the most common bacteria isolated from nontraumatic brain abscesses? a. Staphylococcus b. Enteric gram-negative rods c. Streptococcus d. Clostridium C The most common organism isolated from nontraumatic brain abscesses include aerobic, anaerobic, and microaerophilic streptococci. Streptococci, such as S. anginosus, S. intermedius, and S. constellatus, are isolated in 50% to 70% of cases. REF: 863 OBJ: Level 1: Recall 25. Diagnosis of central nervous system (CNS) infections is based on: a. neurologic symptoms. b. physical symptoms. c. history. d. laboratory examination of CSF. D The diagnosis of CNS infections is based on examination of CSF samples obtained by lumbar puncture. REF: 864 OBJ: Level 1: Recall 26. A cerebrospinal fluid (CSF) sample collected from a child yields the following results: turbid and cloudy, very high total protein levels, and very low glucose levels. What would the probable diagnosis be? a. Bacterial meningitis b. Aseptic meningitis c. Encephalitis d. Brain abscess A In acute bacterial meningitis, the CSF is turbid or cloudy because protein levels are significantly raised. Glucose levels are very low (less than 40% of serum glucose concentration) in most patients with bacterial meningitis. REF: 864 OBJ: Level 3: Synthesis

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Chapter 34: Gastrointestinal Infections and Food Poisoning. Answers Explained Chapter 34: Gastrointestinal Infections and Food Poisoning Test Bank MULTIPLE CHOICE 1. Why is the travel history of the patient important when evaluating a person with acute diarrhea? a. Travel to different countries puts one at risk for various infections. b. Some countries are dirtier than others. c. The United States is clean, and usually bad infections cannot be contracted here. d. All of the above. A Recent travel history is also important, as travelers to underdeveloped areas are at risk for various types of infections. REF: 836 OBJ: Level 2: Interpretation 2. All of these patient history questions will help focus the search for the pathogen except: a. Does the patient have a history of previous gastrointestinal symptoms? b. Did the patient eat any hot food? c. Does the patient have an underlying illness? d. Is the patient taking any medication? B Chronic inflammation, immunosuppression, and medications may themselves be causes for diarrhea. A patient’s diarrhea may not be caused by an infection. REF: 836 OBJ: Level 1: Recall 3. How is diarrhea disease usually contracted? a. By air b. By blood c. By contaminated food or water d. By respiratory droplet C Although there are exceptions, diarrheal pathogens are usually acquired by ingesting a contaminated food or beverage. REF: 836 OBJ: Level 1: Recall 4. How does the small intestine try to prevent infection? a. Caustic secretions b. Acidic secretions c. Anatomic structure d. Peristalsis D The small intestine has a different mechanism to prevent infection—it is constantly in motion (peristalsis). Organisms that rely on adhering to the intestinal wall to cause infection may be hampered by the peristaltic movements. REF: 836 OBJ: Level 2: Interpretation 5. What defense mechanism does the colon have to guard against infection? a. IgA antibody is produced. b. IgE antibody is produced. c. Nonspecific immune defenses are resident here and take care of pathogens. d. The anatomic structure makes it tough for organisms to adhere. A The colon also has defense mechanisms. Antibody is produced locally—primarily IgA—which may have some effect against pathogenic organisms. Also, an enormous number of other bacteria already live in the colon (the host’s normal gut flora). REF: 836 OBJ: Level 1: Recall 6. What is the most common cause of travelers’ diarrhea? a. Giardia lamblia b. Escherichia coli c. Entamoeba histolytica d. Clostridium difficile B Travelers’ diarrhea is most commonly caused by enteropathogenic E. coli. This illness has a short incubation period (usually less than 24 hours) and normally lasts between 1 and 3 days. If a diarrheal illness lasts longer than this or develops in the days or weeks after a traveler returns home, the patient more likely has a different pathogen. REF: 837 OBJ: Level 1: Recall 7. What is the most common cause of death among patients with diarrhea? a. Sepsis b. Septic shock c. Dehydration d. Secondary bacterial infections C The first step in the physical examination of a patient with a diarrheal illness is to determine the patient’s state of hydration, as dehydration is the most common cause of death in patients with diarrhea. REF: 838 OBJ: Level 1: Recall 8. What type of diarrheal illness has no fever and no blood or pus in the stool? a. Diarrhea where the mucosal surface is invaded b. Diarrhea where the full bowel thickness is invaded c. Diarrhea caused by endotoxins d. Diarrhea caused by enterotoxins D The lack of fever and absence of blood or pus in the stool points toward an enterotoxin-mediated illness. The bacteria associated with enterotoxin production do not invade the gut wall, and the toxin does not elicit an inflammatory response, so microscopic examination of the stool does not reveal any red or white blood cells. REF: 839 OBJ: Level 2: Interpretation 9. What type of diarrheal illness has a rapid onset of symptoms after food ingestion (usually less than 12 hours)? a. Diarrhea where the mucosal surface is invaded b. Diarrhea where the full bowel thickness is invaded c. Diarrhea caused by endotoxins d. Diarrhea caused by enterotoxins D The rapid onset of symptoms after food ingestion suggests that the illness in this case is enterotoxin mediated. The preformed toxin is usually present in the contaminated food and is then ingested by the patient, leading to the symptoms. Because toxin may already be present and can act fairly proximally in the bowel, the incubation period is relatively short, usually less than 12 hours. REF: 840 OBJ: Level 2: Interpretation 10. All of the following organisms can cause enterotoxin-mediated diarrhea except: a. Salmonella typhi. b. Clostridium perfringens. c. Vibrio cholerae. d. Staphylococcus aureus. A Enterotoxigenic E. coli accounts for the largest percentage of cases of diarrhea in travelers to underdeveloped areas. Other organisms responsible for enterotoxin-mediated disease are Vibrio cholerae, Staphylococcus aureus, Clostridium perfringens, and Bacillus cereus. REF: 840 OBJ: Level 1: Recall 11. What type of diarrheal illness produces fever, leukocytosis in peripheral blood, and fecal leukocytes? a. Diarrhea in which the mucosal surface is invaded b. Diarrhea in which the full bowel thickness is invaded c. Diarrhea caused by endotoxins d. Diarrhea caused by enterotoxins A As opposed to the enterotoxin-mediated illnesses, organisms that invade the bowel mucosal surface cause an inflammatory response. This is manifested by the presence of fecal leukocytes, and the organisms may also cause fever and leukocytosis in peripheral blood. REF: 840 OBJ: Level 2: Interpretation 12. All the following organisms invade the bowel mucosal surface to produce diarrhea except: a. Salmonella spp. b. Vibrio cholerae. c. Campylobacter spp. d. Shigella spp. B The most common organisms that invade the bowel mucosal surface to produce diarrhea include Salmonella spp., Campylobacter spp., Shigella spp., some Escherichia coli, and Entamoeba histolytica. REF: 840 OBJ: Level 1: Recall 13. What common organism invades the full thickness of the bowel with lymphatic spread? a. Vibrio cholerae b. Campylobacter jejuni c. Salmonella typhi d. Aeromonas spp. C The most common invasive enteric organisms are S. typhi and Yersinia enterocolitica. REF: 840 OBJ: Level 2: Interpretation 14. What diarrheal illness occurs when organisms invade through the bowel wall, cause bacteremia, and also cause a mesenteric lymphadenitis that may be confused with appendicitis? a. Diarrhea in which the mucosal surface is invaded b. Diarrhea in which the full bowel thickness is invaded c. Diarrhea caused by endotoxins d. Diarrhea caused by enterotoxins B Salmonella typhi and Yersinia enterocolitica organisms can invade through the bowel wall, cause bacteremia, and also cause a mesenteric lymphadenitis that may be confused with appendicitis. Diarrhea often is not the presenting symptom, and patients may actually have constipation at the onset of illness. REF: 840 OBJ: Level 2: Interpretation 15. What virus is the leading cause of diarrhea in children younger than age 5? a. Enteric adenoviruses b. Astroviruses c. Rotavirus d. Calicivirus C Rotaviruses are the major cause of diarrhea in children younger than age 5, causing an estimated 130 million episodes of illness worldwide each year. REF: 841 OBJ: Level 1: Recall 16. What virus causes an acute self-limited diarrheal illness that is highly contagious through contaminated food, water, fomites, or person-to-person contact and is associated with vomiting and low-grade fever? a. Astroviruses b. Rotaviruses c. Enteric arenaviruses d. Norovirus D The noroviruses are named after the original strain (Norwalk virus), first isolated in patients from a town with that name in Ohio in 1968. These viruses cause an acute, self-limited diarrheal illness associated with vomiting and low-grade fever. The disease is highly contagious and is transmitted by the fecal-oral route, fecally contaminated food or water, environmental fomites, and by person-to-person contact. REF: 841 OBJ: Level 2: Interpretation 17. Which of the following is an opportunistic virus that can lead to diarrhea in an immunocompromised host? a. Rubella b. Parvo B19 c. Cytomegalovirus d. Filovirus C Cytomegalovirus (CMV) is an opportunistic virus that can lead to diarrhea. Typical symptoms consist of watery diarrhea, pain, and blood in the stool. Fever is often present. REF: 848 OBJ: Level 1: Recall 18. What is the most common cause of bacterial gastroenteritis in the world? a. Salmonella typhi b. Campylobacter jejuni c. Shigella sonnei d. Yersinia enterocolitica B Although various Campylobacter spp. have been isolated as a cause of diarrhea, C. jejuni is the most common bacterial cause of gastroenteritis in the world. REF: 841 OBJ: Level 1: Recall 19. Disease caused by which of the following organisms has fever, abdominal cramping, diarrhea, and stools with gross blood and pus? a. Staphylococcus aureus b. Clostridium difficile c. Campylobacter jejuni d. Bacillus cereus C Infections with this organism usually result in a self-limited disease characterized by fever, abdominal cramping, and diarrhea. The incubation period is normally 2 to 5 days, but in some cases has extended up to 10 days. Diarrhea is often preceded by a period of febrile malaise with myalgias and abdominal pain. Stools may have gross blood and pus present. REF: 842 OBJ: Level 2: Interpretation 20. What is the environmental reservoir of Campylobacter? a. Lakes and rivers b. Fish c. Arthropod vector d. Wild and domestic animals D The environmental reservoir of Campylobacter includes both wild and domestic animals, most frequently birds. This is usually a foodborne infection, often with poultry as the source. REF: 842 OBJ: Level 1: Recall 21. What organism that causes gastroenteritis can be found in aquaculture-farmed fish? a. Salmonella b. Campylobacter c. Vibrio d. Shigella A Nontyphoidal Salmonella spp. can lead to gastroenteritis through ingestion of contaminated meat, poultry, eggs, and dairy products, as well as aquaculture-farmed fish and shellfish. REF: 842 OBJ: Level 2: Interpretation 22. What organ is colonized in a patient that carries Salmonella typhi? a. Colon b. Gallbladder c. Rectum d. Small intestine B The organism can frequently be recovered from both blood and stool cultures. Appropriate antibiotic use results in clinical improvement; however, stool cultures often remain positive, which can serve as a source of infection for other individuals. Some patients can also develop chronic colonization of their gallbladder and biliary tree, leading to persistent shedding of the organism and infections in multiple other people (the classic “Typhoid Mary” case). REF: 842 OBJ: Level 1: Recall 23. What toxin does Shigella spp. produce? a. Typhi b. Enterotoxin c. Shiga d. Campy C The bacteria produce several toxins, one of which is the Shiga toxin, which can have cytotoxic, enterotoxic, and neurotoxic effects. REF: 842 OBJ: Level 1: Recall 24. What diarrheal pathogen can produce a disease that may lead to hemolytic-uremic syndrome (hemolytic anemia, low platelet count, and kidney failure)? a. Enterohemorrhagic Escherichia coli (EHEC) b. Enteroinvasive E. coli (EIEC) c. Enteropathogenic E. coli (EPEC) d. Enterotoxigenic E. coli (ETEC) A EHEC usually starts as a watery diarrhea. However, over the next day or two, abdominal pain increases and stools become bloody. Stool may contain some fecal leukocytes, so there may be some confusion between this infection and EIEC or Shigella. Although the disease is usually self-limited, patients can develop hemolytic-uremic syndrome (HUS), characterized by hemolytic anemia, low platelet count, and kidney failure. REF: 842 OBJ: Level 2: Interpretation 25. What types of stools are characteristic of someone who has cholera? a. Black-blood stools b. Coffee-ground stools c. Black tar stools d. Rice-water stools D Once in the cell, through various enzymatic effects, the toxin results in an increase in the amount of cyclic adenosine monophosphate, which causes the cell to secrete large amounts of water and electrolytes. This increased secretion causes the rice-water stools characteristic of cholera. REF: 843 OBJ: Level 2: Interpretation 26. A man and his family drive to the coast and have an oyster dinner. A couple of days later, the man arrives at the emergency department with a fever, bullous skin lesions, and diarrhea. He is extremely ill and the physician questions whether he is septic. Blood and stool specimens are collected. The microbiologist notices curved gram-negative rods on the stool Gram stain. What is the most probable organism causing this condition? a. Yersinia enterocolitica b. Cryptosporidium jejuni c. Vibrio vulnificus d. Vibrio cholerae C V. vulnificus is the most virulent of all noncholera vibrios, causing an often fulminant illness characterized by sepsis and bullous skin lesions in patients with a recent ingestion of shellfish (i.e., raw oysters). This Vibrio sp. is part of the marine flora, making a common colonizer of a large percentage of oysters harvested in the warmer months. REF: 843 OBJ: Level 3: Synthesis 27. What is the most important cause of iatrogenic diarrhea in adults? a. Yersinia enterocolitica b. Cryptosporidium jejunum c. Vibrio vulnificus d. Clostridium difficile D C. difficile is the most important cause of hospital-acquired diarrhea in adults. This infection demonstrates the importance of normal colonic bacterial flora in preventing disease. REF: 844 OBJ: Level 1: Recall 28. What is the most commonly identified intestinal parasite in the United States? a. Giardia lamblia b. Entamoeba histolytica c. Cryptosporidium parvum d. Microsporidia A The most commonly identified intestinal pathogen in the United States, G. lamblia, is acquired by ingestion of contaminated water and person-to-person spread. REF: 845 OBJ: Level 1: Recall 29. What intestinal parasite is able to leave the intestines and cause metastatic diseases, especially liver abscesses? a. Giardia lamblia b. Entamoeba histolytica c. Cryptosporidium parvum d. Microsporidia B The trophozoites of E. histolytica are able to leave the intestine and can cause metastatic illness, most frequently as a liver abscess. REF: 845 OBJ: Level 1: Recall 30. What condition caused by acute diarrheal disease can significantly contribute to the morbidity and mortality of the disease? a. Metabolic alkalosis b. Metabolic acidosis c. Volume depletion d. Starvation C The most important factor to consider when treating a patient with acute diarrhea is his or her hydration status. Volume depletion and electrolyte derangements are major sources of morbidity and mortality from diarrheal illnesses. Since patients lose electrolytes in diarrheal stools, rehydration cannot occur with water alone. The best hydration solution contains both glucose and sodium. REF: 852 OBJ: Level 2: Interpretation 31. All of the following organisms are commonly implicated in a foodborne outbreak except: a. Staphylococcus aureus. b. Salmonella spp. c. Clostridium botulinum. d. Vibrio cholerae. D Vibrio cholerae causes the disease cholera. The most commonly identified bacterial agents involved in foodborne outbreaks are Salmonella spp., C. jejuni, S. aureus, Clostridium botulinum, and C. perfringens. G. lamblia, Cryptosporidium, and Cyclospora have also been associated with outbreaks, usually linked to contaminated fruits and vegetables. REF: 846 OBJ: Level 1: Recall 32. A microbiologist is reading a Gram stain and observes gram-negative, curved rods with a seagull-wing appearance. What organism could this be? a. Campylobacter or Vibrio b. Shigella or Vibrio c. Campylobacter or Shigella d. All of the above A The bacterial pathogen may be visible on direct microscopic examination of the stool. If gram-negative, curved rods with a sea-gull-wing appearance are present, the patient may have a Campylobacter or Vibrio infection. REF: 849 OBJ: Level 2: Interpretation 33. What organism grows best at 42 C and in a reduced oxygen atmosphere (5% to 10%)? a. Shigella sonnei b. Clostridium difficile c. Campylobacter jejuni d. Escherichia coli C C. jejuni grows best at 42 C and in an atmosphere of reduced oxygen content (5% to 10%), making them microaerophilic organisms. REF: 849 OBJ: Level 1: Recall

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Chapter 33: Skin and Soft Tissue Infections. Answers Explained Chapter 33: Skin and Soft Tissue Infections Test Bank MULTIPLE CHOICE 1. What is the most common bacterium found on the skin? a. Coagulase-negative staphylococci b. Coagulase-negative streptococci c. Escherichia coli d. Pseudomonas aeruginosa A Usual flora of the skin consists of those microbes able to adapt to the high salt concentration and drying effects of the skin. Important microflora includes gram-positive cocci, such as staphylococci and streptococci. Coagulase-negative staphylococci, such as Staphylococcus epidermidis, are permanent skin residents; coagulase-positive Staphylococcus aureus is a transient colonizer. REF: 805 OBJ: Level 1: Recall 2. Which of the following organisms are responsible for impetigo? a. Staphylococcus epidermidis b. Streptococcus pyogenes c. Enterococcus faecalis d. Streptococcus agalactiae B Impetigo is a common pyoderma that is most often seen in children. Historically, the majority of cases were caused by group A streptococci (GAS; Streptococcus pyogenes), although S. aureus has become the predominant pathogen over the last 15 years. REF: 809 OBJ: Level 1: Recall 3. A group of swim team members breaks out in a rash (folliculitis) the day after swimming at the pool. What organism is probably responsible for this outbreak? a. Staphylococcus aureus b. Enterococcus c. Escherichia coli d. Pseudomonas aeruginosa D Folliculitis is an inflammation and infection of hair follicles. S. aureus is the most common etiologic agent of folliculitis, although P. aeruginosa has been implicated in cases acquired from contaminated swimming pools or whirlpools. REF: 811 OBJ: Level 2: Interpretation 4. What is a form of folliculitis in bearded men? a. Sycosis barbae b. Furuncle c. Carbuncle d. Impetigo A Sycosis barbae is a form of folliculitis occurring in bearded men. REF: 811 OBJ: Level 1: Recall 5. Which of these is an abscess that extends more deeply into the subcutaneous fat and may have multiple draining sites? a. Furuncle b. Carbuncle c. Folliculitis d. Impetigo B A carbuncle is an abscess that extends even more deeply into the subcutaneous fat and may have multiple draining sites. Staphylococcus aureus is the most common causative pathogen. REF: 811 OBJ: Level 1: Recall 6. Besides antimicrobial therapy, how are most carbuncles treated? a. Teabags to draw the poison out b. Moist heat, then cold compresses c. Surgical drainage d. Squeezing to express the pus and necrotic tissues C Furuncles usually can be managed by the application of moist heat and antimicrobial therapy. Surgical drainage is generally needed for most carbuncles. REF: 811 OBJ: Level 1: Recall 7. What condition presents as a localized area of mildly painful erythema, warmth, and swelling of the skin with poorly demarcated margins? a. Impetigo b. Carbuncles c. Furuncles d. Cellulitis D Cellulitis is a diffuse inflammation and infection of the superficial skin layers. It appears as a localized area of mildly painful erythema, warmth, and welling of the skin with poorly demarcated margins. REF: 810 OBJ: Level 2: Interpretation 8. What is erysipelas? a. Inflammation of hair follicle b. A deep form of cellulitis c. A synonym for furuncle d. A synonym for carbuncle B Erysipelas is a deeper form of cellulitis that involves not only the superficial epidermis but also the underlying dermis and lymphatic channels. Erysipelas is characterized as a painful, indurated area of cellulitis with a raised, sharply demarcated border and a typical deep crimson hue. REF: 810 OBJ: Level 1: Recall 9. What is the most infamous type of myonecrosis? a. Tetanus b. Flesh-eating Streptococcus c. Gas gangrene d. Ebola hemorrhage C Clostridial myonecrosis, also known as gas gangrene, is the most infamous type of myonecrosis and is caused by histotoxic clostridia, which include Clostridium septicum, C. perfringens, C. novyi, C. histolyticum, and C. sordellii. REF: 813 OBJ: Level 1: Recall 10. What condition causes the nail margin to become painful, red, warm, and swollen with pus? a. Furuncle b. Carbuncle c. Erysipelas d. Paronychia D Paronychia is an infection of the cuticle surrounding the nail bed. Cases generally follow minor trauma, such as removing a hangnail. The involved part of the finger at the nail margin becomes painful, red, warm, and swollen, and pus may be expressed from around the nail bed. REF: 811 OBJ: Level 2: Interpretation 11. What organism is known to cause severe necrotic cellulitis and primary sepsis? a. Vibrio vulnificus b. V. parahaemolyticus c. Campylobacter spp. d. Staphylococcus aureus A V. vulnificus, a halophilic vibrio, has been recognized as a virulent pathogen since 1976 when it was first described. The organism is known to cause severe necrotic cellulitis and primary sepsis. REF: 808 OBJ: Level 1: Recall 12. Purpura fulminans, a skin manifestation of DIC, is associated with which condition? a. Hepatitis b. Meningococcemia c. Encephalitis d. Salmonella B A skin manifestation of DIC is purpura fulminans. This syndrome has classically been associated with meningococcemia, but bloodstream infections with S. aureus, Streptococcus pneumoniae, and Haemophilus influenzae have also been associated. It is characterized by rapidly developing skin hemorrhage and necrosis, and peripheral gangrene accompanied by shock syndrome. REF: 817 OBJ: Level 2: Interpretation 13. What happens in the late stages of toxic shock syndrome as a result of the production of TSST-1? a. Bruising b. Disseminated intravascular coagulation (DIC) c. Desquamation d. Bacteremia C Cutaneous desquamation occurs in toxic shock syndrome (TSS) because of the production of staphylococcal exotoxins. TSS clinical presentations include a diffuse sunburn-like erythroderma appearing early in the course and accompanied by fever, hypotension, and evidence of multiorgan dysfunction. Desquamation of skin, especially on the palms and soles, occurs during the convalescent stage of the illness. REF: 829 OBJ: Level 2: Interpretation 14. What causes scarlet fever? a. S. aureus b. Endotoxin c. Proteases d. Erythrogenic toxin D Scarlet fever is a form of GAS disease that can occur when the infecting strain produces streptococcal pyrogenic exotoxins (SPEs). It occurs mostly in children and concomitantly with pharyngeal infection, although it can also be seen with infections at other sites. REF: 830 OBJ: Level 1: Recall 15. What organism produces “rat bite fever?” a. Streptobacillus moniliformis b. Staphylococcus aureus c. Borrelia burgdorferi d. Chlamydia trachomatis A Two bacterial diseases, rare in the United States, are included under the general term rat-bite fever: streptobacillosis, caused by Streptobacillus moniliformis, and spirillosis, caused by Spirillum minus (minor). REF: 830 OBJ: Level 1: Recall 16. What organism causes the Buruli ulcer? a. Streptococcus agalactiae b. Mycobacterium ulcerans c. Corynebacterium jejuni d. Mycobacterium leprae B M. ulcerans infection usually occurs as a single, pruritic ulcer with undermined edges, also known as a Buruli ulcer. M. ulcerans infection is associated with swamps and may be a chronic infection in tropical climates. REF: 819 OBJ: Level 1: Recall 17. What is the most sensitive method of diagnosing cutaneous infections? a. Culture b. Enzyme immunoassay (EIA) c. Polymerase chain reaction (PCR) d. DNA probe A Culture is still the most sensitive method of diagnosing cutaneous infections. Agents of primary infections are recovered in routine culture using primary nonselective media, such as blood and chocolate agars, and selective media, such as MacConkey agar. REF: 817 OBJ: Level 1: Recall 18. The clinical syndrome of Rocky Mountain spotted fever (RMSF) can be confused with which of the following conditions? a. Lyme disease b. Atypical measles c. Smallpox d. Allergic reactions B The clinical syndrome of RMSF may be confused with atypical measles, meningococcal bloodstream infection, and other forms of bacterial sepsis, secondary syphilis, typhoid fever, enteroviral infection, and leptospirosis. REF: 831 OBJ: Level 2: Interpretation 19. What organism, which usually causes respiratory infections, causes maculopapular and vesicular rashes, urticaria, and immunologically mediated erythema nodosum and erythema multiform? a. Streptococcus pneumoniae b. Klebsiella pneumoniae c. Mycoplasma pneumoniae d. Haemophilus influenzae C Although a primary pathogen of the respiratory tract, Mycoplasma can cause a variety of dermatologic findings including maculopapular and vesicular rashes, urticaria, and the hypersensitivity reactions erythema nodosum and erythema multiforme (EM), including EM major (Stevens-Johnson syndrome). REF: 819 OBJ: Level 2: Interpretation 20. What is a circumscribed, hyperkeratotic, rough-textured, painless papule called? a. Skin tick b. Mole c. Freckle d. Wart D There are over 100 types of human papillomaviruses (HPV), with most human infections being asymptomatic or leading to warts, benign proliferations of skin, or mucosal cells. Common warts (circumscribed, hyperkeratotic, rough-textured, painless papules varying in size from several millimeters to large masses), plantar warts (flat, hyperkeratotic lesions of the plantar surface of the feet that may be painful), and flat warts (smooth, slightly elevated, usually multiple lesions varying in size from 1 millimeter to 1 centimeter) are typical cutaneous manifestations. REF: 824 OBJ: Level 2: Interpretation 21. What disease results from a reactivation of the varicella-zoster virus that demonstrates a vesicular eruption in a unilateral dermatomal distribution? a. Shingles b. Chicken pox c. Infectious mononucleosis d. Rubella A Varicella-zoster virus is a herpesvirus that exhibits, like other members of the family Herpesviridae, lifelong latency in the human host. With reactivation, the virions move along peripheral sensory nerves of the skin, leading to the appearance of a vesicular eruption in a unilateral dermatomal distribution. The resulting condition is called herpes zoster or shingles. REF: 825 OBJ: Level 2: Interpretation 22. What is herpetic whitlow? a. Primary herpetic lesions of the genitals b. Primary herpetic lesions of the finger c. Primary herpetic lesions of the anus d. Primary herpetic lesions of the lip B A presentation of cutaneous HSV is herpetic whitlow, or primary herpetic lesions of the finger (Figure 33-22). This can be caused by either HSV-1 or HSV-2. Usually a single digit is involved, with the appearance of one or more deep vesicles that may coalesce. REF: 823 OBJ: Level 1: Recall 23. What causes rubeola? a. Calicivirus b. Herpesvirus c. Paramyxovirus d. Torovirus C Rubeola (measles) is caused by a paramyxovirus and is spread by direct contact with respiratory secretions of infected persons. REF: 824 OBJ: Level 1: Recall 24. What causes rubella? a. Calicivirus b. Herpesvirus c. Paramyxovirus d. Togaviridae D Rubella, also known as German measles, is a viral infection of children and adults that resembles measles. It is characterized by fever, rash, and lymphadenopathy. The virus is in the Togaviridae family (genus Rubivirus). REF: 822 OBJ: Level 1: Recall 25. What causes erythema infectiosum? a. Parvovirus b. Herpesvirus c. Paramyxovirus d. Togaviridae A Erythema infectiosum, or fifth disease, is one of the common viral exanthems of childhood. It is caused by the human parvovirus B19 (genus Erythrovirus, family Parvoviridae), which replicates in erythrocyte precursor cells. Erythema infectiosum, or fifth disease, is one of the common viral exanthematous diseases of childhood. REF: 822 OBJ: Level 1: Recall 26. All of the following viruses cause a characteristic viral syndrome, which includes severe bleeding manifestations except: a. Ebola. b. rabies. c. Junin. d. Marburg. B A number of viruses of the Togaviridae (e.g., yellow fever and dengue virus), Arenaviridae (e.g., Junin and Machupo viruses), and Bunyaviridae (e.g., Hantavirus) families, as well as several ungrouped viruses (e.g., Ebola, Marburg, and Lassa fever viruses), may cause a characteristic viral syndrome (fever, headache, myalgias, nausea vomiting, abdominal pain, prostration) accompanied by severe bleeding manifestations (e.g., gastrointestinal bleeding, hematuria). REF: 822 OBJ: Level 1: Recall 27. What is ringworm? a. A parasitic skin infection b. A bacterial skin infection c. A fungal skin infection d. A viral skin infection C The classic lesion of a dermatophyte infection is a circular scaly patch of erythema with a raised border. Often the edges are more inflamed than the center. These infections are also known as ringworm, reflecting the tendency of some lesions to expand annularly. REF: 826 OBJ: Level 1: Recall 28. What is thrush? a. Tinea unguium b. Tinea corporis c. Dermatophytosis d. Oral candidiasis D Thrush is a type of candidiasis involving the oral mucosa and is characterized by white, curdlike patches on the tongue, palate, or buccal mucosa. These patches adhere to the mucosa but can be removed by scraping, leaving a raw, erythematous base. REF: 808 OBJ: Level 1: Recall 29. What is swimmer’s itch? a. When cercariae larvae penetrate human skin, causing dermatitis b. When arthropods deposit larvae in human skin, causing dermatitis c. When food or water causes dermatitis d. When Pseudomonas spp. causes dermatitis A Dermatitis caused by schistosomes is most often seen when the infective larvae of bird and animal schistosomes infect humans. Free-living larvae, or cercariae, that have developed in snails penetrate the skin of humans bathing or swimming in infected waters. This results in an intensely pruritic, papular eruption known as cercarial dermatitis or “swimmer’s itch.” REF: 807 OBJ: Level 1: Recall 30. What is river blindness? a. Infection with Naegleria fowleri b. Infection with Onchocerca volvulus c. Infection with Strongyloides stercoralis d. Infection with Entamoeba histolytica B Onchocerca volvulus is transmitted by black flies, and causes subcutaneous nodules and river blindness. The most important manifestation of onchocerciasis, (so named because transmission is most often in rural villages near rapidly flowing streams), is the result of this infiltration of the eye by the organisms. REF: 826 OBJ: Level 1: Recall

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Chapter 32: Upper and Lower Respiratory Tract Infections. Answers Explained Chapter 32: Upper and Lower Respiratory Tract Infections Test Bank MULTIPLE CHOICE 1. When reading culture plates from respiratory specimens, what must the microbiologist take into consideration? a. The types of organisms normally found at the culture site b. The amount of media inoculated c. The quality control performed on the media d. The patient’s physician A Laboratory professionals must consider the types of organism normally found at the site from which a microbiologic specimen was collected to be able to determine whether diagnostic data indicate the presence of a pathogen. Analysis of microbiologic data requires a working knowledge of the normal microbial flora, the clinical setting, and the patient’s presentation. REF: 769 OBJ: Level 2: Interpretation 2. If a patient has a throat culture done and the culture reveals the presence of -hemolytic colonies, what does this indicate? a. These organisms are pathogenic and must be treated. b. These organisms are normally found in the pharynx and are normal. c. The patient is suffering from a viral pharyngitis. d. The patient has mouth ulcers that require antiviral treatment. B Isolation of -hemolytic colonies from a pharyngeal culture from a patient with pharyngitis arouses little clinical interest, because -hemolytic streptococci are normal flora in the oropharynx. REF: 767 OBJ: Level 2: Interpretation 3. What should a microbiologist do if he or she finds -hemolytic colonies on a properly collected sputum specimen on a patient suspected of having lobar pneumonia? a. Ignore the colonies because they are normal flora. b. Ignore the colonies because no known pathogens for pneumonia are -hemolytic. c. Do a full workup to identify the organism. d. Suspect a bioterror agent, and send the isolate to a laboratory response network (LRN) reference laboratory. C Isolation of an -hemolytic colony from a properly collected sputum specimen or bronchial aspirate in the clinical setting of lobar pneumonia should prompt full identification of the organism and perhaps initiation of empirical therapy for possible pneumococcal infection. REF: 767 OBJ: Level 2: Interpretation 4. A patient’s normal pharyngeal flora can be altered by all of the following except: a. broad-spectrum antibiotics. b. recent hospitalization. c. chronic illness. d. visiting a nursing home. D Normal upper respiratory tract flora in an asymptomatic patient may change depending on the clinical setting. Patients who have previously received broad-spectrum antibiotics, have been hospitalized recently, or who have chronic illnesses may have different pharyngeal flora. REF: 767 OBJ: Level 1: Recall 5. All of the following factors can help the microbiologist differentiate between colonization and infection except: a. presence of a pure culture or mixed flora on the culture plates. b. method and site of collection of the specimen. c. presence of white blood cells (WBCs) and the number of organisms seen on Gram stain. d. A compatible clinical syndrome. A The isolation of certain organisms from respiratory specimens may represent either colonization or disease, depending on the circumstances. An interpretation must be based on several factors. The method and site of collection of the specimen can influence the risk of contamination with organisms that are part of the normal flora. Characteristics of the specimen such as the presence of white blood cells and the number of organisms in the specimen can help distinguish between colonization and infection. Most important, a compatible clinical syndrome should be present to determine whether the presence of a potential pathogen is clinically relevant. REF: 768 OBJ: Level 2: Interpretation 6. Which of the immunocompromised circumstances listed here is a form of functional immunodeficiency? a. Sex b. Age c. Chronic illness d. Pregnancy B Age is a form of functional immunodeficiency. Infants and the elderly are more susceptible to certain respiratory tract infections and are more likely to develop complications of these infections. REF: 768 OBJ: Level 1: Recall 7. What is the cause of reduced clearance of respiratory secretions that predisposes people to respiratory infections? a. Obstruction of a foreign body b. Alterations in the viscosity of the mucus c. Immature anatomic development d. All of the above D In addition to age as a compromising factor, reduced clearance of secretions or obstruction of an area in either the upper or the lower respiratory tract predisposes to infection and can, on occasion, seriously compromise respiratory tract function. Decreased clearance of respiratory secretions may result from the following: immature anatomic development, transient reduction in function of the mucociliary mechanism, obstruction by a foreign body, previous disease that alters the normal respiratory tract anatomy, and alterations in the viscosity of mucus. REF: 769 OBJ: Level 1: Recall 8. What bacteria may cause up to 50% of all cases of pneumonia in the summer months? a. Mycoplasma pneumoniae b. Streptococcus pneumoniae c. Klebsiella pneumoniae d. Haemophilus influenzae A Diseases associated with M. pneumoniae typically occur throughout the year, without marked seasonal variability. The incidence of viral infections and secondary bacterial pneumonias is reduced during the summer months; therefore M. pneumoniae may cause up to 50% of all pneumonias in the summer months. REF: 769 OBJ: Level 1: Recall 9. What is helpful when initiating empiric antimicrobial therapy? a. Knowing the patient’s age b. Knowing the pathogens most likely to cause a particular type of infection c. Knowing a patient’s medical history d. Knowing the anatomy of the respiratory tract B When empiric antimicrobial therapy is necessary, it is important to have a working knowledge of the organisms most likely to cause the type of infection observed and of the antibiotics that are most likely to be effective. REF: 769 OBJ: Level 2: Interpretation 10. Elements of the respiratory tract that can help prevent infection include which of the following? a. Nasal hair b. Normal flora c. Coughing d. All of the above D Elements of the respiratory tract that help prevent infection include nasal hair, mucociliary cells that line mucosal surfaces, coughing, normal flora, and phagocytic inflammatory cells. REF: 766 OBJ: Level 2: Interpretation 11. All the following are virulence factors that allow microorganisms to produce disease except: a. adherence. b. toxin elaboration. c. mucus production. d. host evasion. C Virulence factors involved in disease-producing mechanisms, such as adherence, toxin elaboration, and host evasion, enable the microorganism to complete this process. REF: 770 OBJ: Level 1: Recall 12. Why is pharyngitis produced by group A Streptococcus treated with antibiotics? a. To prevent rheumatic fever and acute glomerulonephritis b. To prevent epiglottis c. To prevent swelling of tonsils d. To prevent swelling of soft tissues in the pharynx A The goals of antibiotic treatment of streptococcal pharyngitis include amelioration of the symptoms, limitation of transmission of the infection to contacts (especially in school-age children), and prevention of the serious complications of acute rheumatic fever and acute glomerulonephritis. REF: 772 OBJ: Level 2: Interpretation 13. What are the two most frequently identified bacterial causes of community-acquired sinusitis? a. Staphylococcus aureus and Escherichia coli b. Streptococcus pneumoniae and Haemophilus influenzae c. S. pneumoniae and Mycoplasma pneumoniae d. H. influenzae and Neisseria meningitidis B Common viruses causing acute sinusitis include rhinovirus, parainfluenza, and influenza viruses. S. pneumoniae and H. influenzae are the bacterial pathogens identified most frequently in community-acquired infections. REF: 773 OBJ: Level 1: Recall 14. Acute sinusitis usually occurs as a complication of: a. bacterial pneumonia. b. viral pneumonia. c. the common cold. d. streptococcal pharyngitis. C Acute sinusitis is usually a complication of common colds or other viral infections of the upper respiratory tract. REF: 773 OBJ: Level 1: Recall 15. What common condition will predispose individuals to acute sinusitis? a. Cold sores b. Ear infections c. Nosebleeds d. Allergies D Respiratory allergies also predispose individuals to acute sinusitis. REF: 773 OBJ: Level 1: Recall 16. All of the following are complications of acute sinusitis except: a. acute pharyngitis. b. meningitis. c. osteomyelitis. d. orbital cellulitis. A Complications of acute sinusitis result from extension of the infection to adjacent areas or structures. These complications include orbital cellulitis, osteomyelitis, meningitis, brain abscess, and cavernous sinus thrombosis. REF: 774 OBJ: Level 1: Recall 17. What organisms are most frequently isolated from cultures of individuals with otitis media? a. Staphylococcus aureus and Escherichia coli b. Streptococcus pneumoniae and Haemophilus influenzae c. S. pneumoniae and Mycoplasma pneumoniae d. H. influenzae and Neisseria meningitidis B Considering the similarities in their pathogenesis, it is not surprising that the same group of pathogens is involved in both acute otitis media and acute sinusitis. S. pneumoniae and H. influenzae account for more than 50% of the isolates from cases of acute otitis media. REF: 775 OBJ: Level 1: Recall 18. What is the most common localized infection of the upper respiratory tract in preschool-age patients? a. Orbital cellulitis b. Acute sinusitis c. Otitis media d. Mastoiditis C Otitis media is the most common localized infection of the upper respiratory tract in pre-school-age patients. One study showed that almost a third of all visits by preschool children to pediatricians involved diseases of the middle ear. REF: 775 OBJ: Level 1: Recall 19. Why do most physicians treat otitis media empirically instead of obtaining cultures before prescribing antibiotics? a. It is hard to hard to obtain cultures from children. b. Cultures do not always correlate with the true pathogen. c. Pathogens causing otitis media never become resistant to antibiotics. d. The predominant infection causing organisms are known. D Because the predominant pathogens for acute otitis media are known, obtaining specimens for culture before initiating therapy is unnecessary in the average case. REF: 776 OBJ: Level 1: Recall 20. What organism causes epiglottis? a. Haemophilus influenzae b. Streptococcus pneumoniae c. Moraxella catarrhalis d. Bordetella pertussis A H. influenzae type b is uniquely associated with epiglottis. REF: 776 OBJ: Level 1: Recall 21. What is the most common complication of pertussis? a. Otitis media b. Pneumonia c. Acute sinusitis d. Streptococcal pharyngitis B The most common complication of pertussis is the pneumonia that occurs in young children. REF: 778 OBJ: Level 1: Recall 22. What is the specimen of choice for recovery of Bordetella pertussis? a. Sputum specimens b. Throat swabs c. Nasopharyngeal swabs d. Bronchial aspirate C Isolation of B. pertussis in culture from nasopharyngeal secretions is the historical standard for diagnosis and exhibits high specificity. Specimens should be collected early in the course of disease (preferably within the first 2 weeks of the onset of cough) from the posterior nasopharynx and should be plated directly onto selective media, such as Bordet-Gengou or Regan-Lowe (RL) for optimal recovery. REF: 778 OBJ: Level 1: Recall 23. What virus causes community-wide seasonal outbreaks of bronchiolitis in infants? a. Rhinovirus b. Parainfluenza virus c. Respiratory syncytial virus (RSV) d. Influenzae virus C RSV also causes community-wide seasonal outbreaks of bronchiolitis in infants. REF: 779 OBJ: Level 1: Recall 24. What is the major cause for chronic bronchitis? a. Acute bronchitis b. Respiratory allergies c. Pneumonia d. Smoking D Whereas acute bronchitis is usually of infectious etiology, chronic bronchitis is usually caused by long-term cigarette smoking and occasionally by other toxic exposures. REF: 781 OBJ: Level 1: Recall 25. How is acute bronchitis differentiated from acute pneumonia? a. The degree and extent of involvement of the lower respiratory tract with the infectious process b. The involvement of the bronchial tree with the infectious process c. The degree of obstruction of the alveoli with the purulent secretions d. The amount of mucus secretion produced by the lower respiratory tract A The distinction between acute bronchitis and acute pneumonia may be subtle. Both of these conditions are lower respiratory tract infections. The differentiation between acute bronchitis and pneumonia depends on the degree and extent of involvement of the lower respiratory tract with the infectious process. REF: 785 OBJ: Level 2: Interpretation 26. What type of pneumonia has been associated with Staphylococcus aureus that produces Panton-Valentine leukocidin? a. Methicillin-resistant pneumonia b. Necrotizing pneumonia c. Bacterial d. Viral B Necrotizing pneumonia with pulmonary hemorrhage has been associated with S. aureus isolates that produce Panton-Valentine leukocidin. REF: 786 OBJ: Level 1: Recall 27. What usually causes community-acquired pneumonias in children during the winter months? a. Haemophilus influenzae b. Streptococcus pneumoniae c. Viral pathogens d. Legionella spp. C Community-acquired pneumonias in children are usually attributable to viral pathogens that cause respiratory tract infections in the community during the winter months. REF: 785 OBJ: Level 1: Recall 28. To what does infection with influenza predispose patients? a. Secondary otitis media b. Secondary sinusitis c. Secondary pharyngitis d. Secondary bacterial pneumonia D During the winter season, the elderly and patients with underlying heart and lung disease, diabetes, renal disease, or immunosuppression are at increased risk for developing primary influenza pneumonia. Additionally, influenza infection predisposes patients to developing a secondary bacterial pneumonia. REF: 783 OBJ: Level 1: Recall 29. The clinical picture of this condition includes an incubation period of 2 to 10 days, fever, with or without cough, and dyspnea. The condition may resolve or progress to a more severe form. What is this condition? a. Severe acute respiratory syndrome (SARS) b. Streptococcal pneumonia c. Viral pneumonia d. Viral bronchitis A A characteristic clinical picture is associated with SARS, although distinguishing SARS from other causes of pneumonia remains a challenge. After an incubation period of approximately 2 to 10 days, the most characteristic symptom is fever, with or without cough, or dyspnea. In most cases, symptoms resolve spontaneously after the first week; however, in more than 20% of patients, symptoms progress to the more severe respiratory distress syndrome, and patients require intensive care and respiratory support. REF: 784 OBJ: Level 3: Synthesis 30. Nosocomial pneumonia are commonly caused by all of the following except: a. Pseudomonas aeruginosa. b. Streptococcus pneumoniae. c. Acinetobacter baumannii. d. methicillin-resistant Staphylococcus aureus (MRSA). B Patients with nosocomial pneumonia are at greater risk for colonization and infection with a wider spectrum of multidrug-resistant bacterial pathogens, such as Pseudomonas aeruginosa, extended-spectrum -lactamase Klebsiella pneumoniae, Acinetobacter baumannii, and MRSA. REF: 789 OBJ: Level 1: Recall 31. Empyema is a collection of: a. fluid in the lung resulting from the pathogenesis of bacterial pathogens. b. fluid in the lung resulting from the pathogenesis of viral pathogens. c. purulent fluid in the pleural space between the lung and the chest wall. d. purulent fluid in the bronchii and alveoli. C Empyema is defined as a collection of purulent fluid in the pleural space between the lung and the chest wall. Although the accumulation of pleural fluid is fairly common in association with acute bacterial pneumonia, most such accumulations are sterile, only a small percentage of which qualify as empyemas. REF: 787 OBJ: Level 1: Recall 32. Chronic pneumonia is a: a. viral pneumonia that lasts for months. b. pneumonia that is caused by a slow-growing bacteria such as Bacillus anthracis and takes months to resolve. c. bacterial pneumonia that becomes resistant to antibiotic therapy. d. pneumonia that appears to resolve clinically, but where radiographic lung abnormalities persist for a long period. D Bacterial pneumonias usually resolve completely over a period of weeks. On occasion, however, resolution of pneumonia is delayed, with radiographic lung abnormalities persisting far beyond the improvement of clinical symptoms. REF: 792 OBJ: Level 1: Recall 33. What organism is the most common opportunistic pathogen that routinely infects patients with HIV/AIDS? a. Pneumocystis (carinii) jirovecii b. Mycoplasma pneumoniae c. Serratia marcescens d. Respiratory syncytial virus (RSV) A Pneumocystis jirovecii pneumonia remains the most common AIDS-associated opportunistic infection, although its incidence has decreased. REF: 796 OBJ: Level 1: Recall

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Chapter 31: Biofilms: Architects of Disease. Answers Explained Chapter 31: Biofilms: Architects of Disease Test Bank MULTIPLE CHOICE 1. What is a biofilm? a. Communities of organisms attached to a solid surface b. The resulting thick, slimy mucous produced in cystic fibrosis c. A slime factor that can be found in your gastrointestinal tract d. The resulting film that is produced by necrotic tissue, bacteria, and immune cells A Biofilms are communities of microorganisms attached to a solid surface; the surface can be either abiotic (nonliving) or living tissue. REF: 753 OBJ: Level 1: Recall 2. Cobiofilms of what two organisms are associated with serious lung infections in cystic fibrosis patients? a. Pseudomonas aeruginosa and Moraxella b. Pseudomonas aeruginosa and Burkholderia cepacia c. Pseudomonas aeruginosa and Mycobacterium tuberculosis d. Pseudomonas aeruginosa and Streptococcus pneumoniae B Cobiofilms of Pseudomonas aeruginosa and Burkholderia cepacia are associated with serious lung infections in patients with cystic fibrosis. REF: 753 OBJ: Level 1: Recall 3. What is a sessile-type biofilm? a. A biofilm made up of free-floating microorganisms b. A multiple-species biofilm c. A biofilm that is attached and made up of multiple species d. A biofilm that is present in an aquatic environment C The sessile phenotype results from attachment and usually develops into a multispecies biofilm that has unique characteristics, making it similar in many ways to hydrated polymers. REF: 753 OBJ: Level 1: Recall 4. Biofilms are a universal strategy for: a. planktonic free-floating organisms. b. increasing plasmid transfer for antibiotic resistance. c. battle sheer forces. d. survival, horizontal gene transfer, and growth. D Biofilms are a universal strategy for survival, horizontal gene transfer, and growth, and a probable ancestor of the planktonic free-floating organisms. REF: 754 OBJ: Level 1: Recall 5. All of the following environmental and key cultural characteristics affect biofilms except: a. movement of host. b. genotypic factors. c. nutritional resources. d. mechanical factors and sheer forces. A Several key environmental and cultural characteristics affect the selection of multispecies biofilm inhabitants. These features include species attachment efficiency, genotypic factors, cyclic stage of biofilm, substrata, nutritional resources, mechanical factors and sheer forces, physicochemical environment, and antiinfective hostile pressure forces. REF: 754 OBJ: Level 1: Recall 6. All of the following organisms are very efficient at converting from planktonic to biofilm biotypes when environmental stresses hit except: a. Coagulase-negative staphylococci. b. Pseudomonas aeruginosa. c. Micrococcus luteus. d. Candida albicans. C It is not by accident that coagulase-negative staphylococci, P. aeruginosa, and C. albicans are some of the most efficient and upregulated prone microbes when selective pressures magnify the need to survive in a biofilm community. These microorganisms are also important human pathogens. REF: 754 OBJ: Level 1: Recall 7. What is stage I of biofilm development? a. Multiplication phase b. Irreversible binding phase c. Layering phase d. Attachment phase D Stage I is the attachment phase that can take only seconds to initiate and is likely induced by environmental signals. REF: 754 OBJ: Level 1: Recall 8. What is stage II of biofilm development? a. Irreversible binding phase b. Multiplication phase c. Attachment phase d. Layering phase A Stage II is characterized as irreversible binding and begins minutes after stage I (attachment). During stage II, cell aggregates are formed and motility is decreased. Toward the end of this stage, exopolysaccharide is produced that is able to trap nutrients and planktonic bacteria. REF: 755 OBJ: Level 1: Recall 9. What is stage III of biofilm development? a. Irreversible binding phase b. Layering phase c. Attachment phase d. Multiplication phase B When cell aggregates become progressively layered, with a thickness greater than 10 m, the biofilm is in stage III. This stage is also referred to as maturation-1. REF: 755 OBJ: Level 1: Recall 10. What is stage IV of biofilm development? a. Multiplication phase b. Thickening phase c. Cell dispersion d. Planktonic stage B When biofilms reach their ultimate thickness, generally greater than 100 m, this is referred to as stage IV or maturation-2. It takes a biofilm several days to reach this stage. REF: 755 OBJ: Level 1: Recall 11. What is stage V of biofilm development? a. Spreading phase b. Multiplication phase c. Cell dispersion d. Layering phase C During stage V, cell dispersion is noted. Some of the bacteria develop the planktonic phenotype and leave the biofilm. REF: 755 OBJ: Level 1: Recall 12. What are the metabolically inert microorganisms present in a biofilm called? a. Spores b. Pheromone cells c. Quorum sensing cells d. Persister cells D Persister cells, essentially metabolically inert microorganisms analogous to bacterial spores, are present in all biofilms and bacterial populations. Persister cells are hypothesized to have disabled programmed cell death or apoptosis. These cells have the greatest potential for maintenance of the gene pool and resistance to environmental stress, including antimicrobial agents. REF: 755 OBJ: Level 1: Recall 13. This layer of a biofilm is exposed to the highest concentration of nutrients and oxygen, containing the most active organisms. What layer is this? a. Outer b. Inner c. Middle d. Substrata A The outermost layer of a biofilm is exposed to the highest concentration of nutrients and oxygen. It contains the most active organisms that primarily resemble the structure and activity of their planktonic counterparts. REF: 755 OBJ: Level 1: Recall 14. In what level of the biofilm do the organisms slightly downregulate their metabolic activity, but still use nutrients and exchange genes? a. Outer b. Intermediate c. Inner d. Substrata B The second layer of the architecture is an intermediate level. Organisms in the second layer downregulate somewhat in their metabolic activity, but they clearly have the capacity to use nutrients, exchange genes, and have the potential for multiple drug resistance. This spatial arrangement, physiologic heterogeneity, and nonuniformity are based on the proximity of microorganisms aligning next to one another. REF: 756 OBJ: Level 2: Interpretation 15. In what level of the biofilm do the organisms downregulate very efficiently and are the least metabolically active? a. Outer b. Intermediate c. Inner d. Substrata C The innermost layer of cells is attached to the substratum and represents the earliest part of the biofilm. These microorganisms also downregulate very efficiently and are the least metabolically active. This is where most of the persister cells are located. REF: 756 OBJ: Level 2: Interpretation 16. In which step of the infectious process could biofilms help bacteria when it comes to developing colonization of indwelling medical devices? a. Downregulation b. Phenotypic variation c. Genotypic variation d. Attachment D Colonization is often an important first step in infectious disease, and biofilms may be an important mechanism of attachment to host tissue and indwelling medical devices. REF: 756 OBJ: Level 2: Interpretation 17. What do biofilms allow members of the microbial community to do? a. Withstand the shear forces of blood and urine b. Remain in a nutrient rich environment c. Survive d. All of the above D Biofilms allow members of the microbial community to withstand the shear forces of blood and urine flow, presumably keeping the microorganisms in a nutrient-rich environment. REF: 757 OBJ: Level 1: Recall 18. Biofilms can protect its members from all of the following except: a. antibodies. b. oxygen-reactive molecules. c. antimicrobial drugs. d. phagocytosis. A Biofilms can afford protection from host defenses including oxygen reactive molecules, antimicrobial proteins, antimicrobial drugs, and phagocytosis. In addition, biofilms protect against pH changes and nutrient deprivation. REF: 757 OBJ: Level 1: Recall 19. How do microorganisms that live in close proximity exchange DNA? a. Frame-shift mutations and plasmid uptake b. Transformation and conjugation c. Conjugation and frame-shift mutations d. All of the above B The biofilm is an optimal environment for the horizontal transfer for DNA. The microorganisms live in close proximity, which facilitates the uptake of DNA by transformation and conjugation. REF: 757 OBJ: Level 1: Recall 20. What process allows the bacteria of the biofilm to spread to other body sites? a. Conjugation b. Metastasis c. Disaggregation d. Planktonization C Disaggregation or detachment of aggregates clearly has the potential of transmitting already upregulated aggregates of microorganisms to other body sites. Similar to cancer metastasis, this is most significant when aggregates spread via the bloodstream. This provides the microorganisms an opportunity to reach almost any body site. REF: 758 OBJ: Level 1: Recall 21. What is the common name for a dental biofilm? a. Cavity b. Gingivitis c. Periodontitis d. Plaque D Dental biofilms, more commonly called plaque, are probably the most well-studied natural biofilm in humans. The microorganisms making up a dental biofilm are considered normal flora of the oral cavity. REF: 758 OBJ: Level 1: Recall 22. The late colonizers in the dental biofilm include all the following except: a. Capnocytophaga. b. Streptococcus salivarius. c. Selenomonas flueggei. d. Prevotella spp. A The late colonizers forming aggregates with the fusobacteria in dental biofilms include Streptococcus salivarius, Propionibacteria, Prevotella, Veillonella, and Selenomonas flueggei. REF: 759 OBJ: Level 1: Recall 23. What happens to dental plaque if it is allowed to remain undisturbed for several days? a. The biofilm disaggregates. b. The persister cells predominate the biofilm. c. Pathogenic bacteria become the main bacterial constituents of the biofilm. d. Nonpathogenic bacteria become the main bacterial constituents of the biofilm. C If the plaque is allowed to remain undisturbed on the teeth for several days, the microbial flora continues to change and becomes composed mainly of anaerobic and facultative anaerobic gram-negative bacilli and spirochetes. The last colonizers of the biofilm are considered pathogenic because of their role in periodontal disease. REF: 759 OBJ: Level 1: Recall 24. What disease, caused by biofilms, consumes more resources in the intensive care unit (ICU) than any other infectious disease? a. Blood cultures positive with coagulase-negative staphylococci b. Urinary tract infections due to gram-negative rods c. Surgical site infections d. Ventilator-associated pneumonia D Ventilator-associated pneumonia, a condition that consumes more resources in the ICU than any single infectious disease, is another example in which biofilms are an important disease-contributing factor. REF: 760 OBJ: Level 1: Recall 25. All the following are laboratory-associated problems related to identifying biofilm-associated diseases except: a. false-positive cultures. b. false-negative cultures. c. viable but noncultural organisms. d. loss of or decreased antimicrobial susceptibility. A The emergence of biofilm-associated diseases causes considerable diagnostic problems for the clinical laboratory. In general, these problems can be classified into five categories: false-negative cultures, viable but nonculturable organisms, underestimated or low colony count, inappropriate specimens, and loss of or decreased antimicrobial susceptibility. REF: 760 OBJ: Level 1: Recall 26. What types of cells in a biofilm are viable but nonculturable? a. Phagocytes b. Persister c. Attachment cells d. Layering cells B Some persister cells found in biofilms are viable but nonculturable bacteria. REF: 760 OBJ: Level 1: Recall 27. Treating infectious diseases has shifted from planktonic susceptibility profiles to: a. therapeutic modalities. b. creative treatments. c. multiple interventions. d. degrading enzymes. C Because of the physical and chemical properties of biofilms, traditional antimicrobial therapy based on planktonic susceptibility profiles will have limited impact on resilient multispecies biofilms. Therapeutic modalities are refocusing on multiple interventions, recognizing that properties of biofilms are similar to organic polymers and not planktonic microbes. REF: 761 OBJ: Level 1: Recall

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Chapter 30: Agents of Bioterror and Forensic Microbiology. Answers Explained Chapter 30: Agents of Bioterror and Forensic Microbiology Test Bank MULTIPLE CHOICE 1. What is bioterrorism? a. The use of bacteria, viruses, fungi, or toxins to injure people, animals, or crops to cause civil unrest b. The use of synthetic biological substances to kill innocent people c. The use of biological substances to kill, maim, or injure as many people as possible d. The use of biohazardous substances to cause chaos A Bioterrorism is the use of bacteria, viruses, fungi, or toxins to injure people, animals, or crops to cause civil or economic unrest. REF: 728 OBJ: Level 1: Recall 2. Who will be most likely to suspect a covert bioterrorism attack? a. Firefighters and the police b. Microbiologists and physicians c. The public health department d. Centers for Disease Control and Prevention (CDC) and Homeland Security B A covert event poses more of a challenge to public health interests. Clinical microbiologists and physicians will most likely be the first to suspect the attack. REF: 728 OBJ: Level 2: Interpretation 3. What document prohibits the use of biological agents during war? a. Geneva Protocol b. Treaty of Versailles c. Antiproliferation Pact d. Law of Armed Conflict A Despite a Geneva Protocol prohibiting the use of biological agents during war signed by many nations, a number of countries began biological warfare research programs in the 1920s. REF: 728 OBJ: Level 1: Recall 4. What classification system was developed in 1999 by academic infectious disease experts, government officials, military intelligence experts, and law enforcement officials? a. Biosafety levels b. High, moderate, and low categories c. A, B, C categories d. Normal, increased, and high categories C In 1999, academic infectious disease experts, national public health experts, Department of Health and Human Services agency representatives, civilian and military intelligence experts, and law enforcement officials met to comment on the threat potential of infectious agents to civilian populations. As a result, agents were placed into one of three categories—A, B, or C—for initial public health preparedness efforts. REF: 729 OBJ: Level 1: Recall 5. What category of bioterrorism agents would have the greatest impact? a. Category A b. Category B c. Category C d. Category D A Category A agents (or Biothreat Level A) would have the greatest impact, whereas categories B and C would have less impact. Although Bacillus anthracis is considered a biosafety level 2 (BSL-2) in clinical laboratories, it is a category A agent in regard to a bioterror threat. REF: 730 OBJ: Level 1: Recall 6. How can biological weapons enter the host? a. Through the respiratory tract b. Through the gastrointestinal (GI) tract c. Through the mucous membranes d. All of the above D Biological weapons can enter the host via the respiratory tract, GI tract, and through the skin and mucous membranes. Dispensing bioterror agents in food or water may not be efficient because of the dilution of the agents. REF: 731 OBJ: Level 2: Interpretation 7. One of the first recorded terror attacks occurred in 1984 in a restaurant in The Dalles, Oregon. What organism was used in this attack? a. Salmonella b. Escherichia coli c. Clostridium d. Staphylococcus A In 1984, the followers of Bhagwan Shree Rajneesh used Salmonella as a weapon to help influence election results in The Dalles, Oregon. By spraying liquid-based Salmonella culture into salad bars in restaurants, these followers caused 750 people to develop culture-positive salmonellosis. REF: 728 OBJ: Level 1: Recall 8. What federal regulation establishes the rules of possession, use, and transfer of select agents and toxins? a. Public Health Security and Bioterrorism Preparedness and Response Act of 2002 b. 42 CFR 73 c. Animal Health and Inspection Act d. Infectious Agent Act B In the 1990s, an individual was arrested in Ohio and in Nevada while carrying Yersinia pestis and anthrax spores in his car. Ironically, ordering and possessing these potential weapons did not necessarily constitute a crime. These cases identified gaps in the law and helped define the need for stricter laws, such as the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 and the recently enacted 42 CFR 73, Possession, Use and Transfer of Select Agents and Toxins; Final Rule (March 2005). REF: 728 OBJ: Level 1: Recall 9. All the following organizations established the Laboratory Response Network except: a. United States Army Medical Research Institute for Infectious Diseases (USAMRIID). b. Centers for Disease Control and Prevention (CDC). c. Central Intelligence Agency (CIA). d. Federal Bureau of Investigation (FBI). C In an effort to increase responsiveness and to create a nationwide ability to rapidly detect the covert or overt deployment of biological weapons in the United States and its territories, the CDC, the Association of Public Health Laboratories (APHL), the FBI, and USAMRIID established the Laboratory Response Network (LRN) in 1999; later that year, most states and territories were implementing training for the detection of biological attacks using standardized LRN protocols. REF: 731 OBJ: Level 1: Recall 10. Which of these are designated as sentinel hospitals in the Laboratory Response Network (LRN)? a. Centers for Disease Control and Prevention (CDC) b. Reference laboratories c. State public health laboratories d. Community hospitals with microbiology laboratories D As defined by the LRN, community hospitals with microbiology capabilities are designated as sentinel (formerly level A) LRN laboratories. Sentinel laboratories must have a biosafety level 2 (BSL-2) facility and the laboratory protocols published on the CDC and American Society for Microbiology (ASM) Web sites to rule out the presence of biological agents. REF: 731 OBJ: Level 1: Recall 11. What is the role of the sentinel laboratory? a. To rule out or refer suspicious isolates b. To identify suspicious isolates c. To act as a reference laboratory for physician office laboratories d. None of the above A The role of a sentinel laboratory is to rule out or refer suspicious isolates, not to identify. Because sentinel laboratories will refer isolates to a regional reference laboratory, clinical laboratory scientists must be aware of the strict requirements for shipping and transporting infectious agents. REF: 731 OBJ: Level 1: Recall 12. What type of anthrax is most deadly and most likely to be seen in a bioterrorism attack? a. Gastrointestinal b. Inhalation c. Cutaneous d. Spinal B Inhalation anthrax occurs when a patient inhales Bacillus anthracis; it usually takes at least 8000 spores to initiate this form of the disease. Inhalation anthrax is the form of anthrax most likely to be seen in a bioterrorism event. Data from the accidental spore release in Sverdlosk, Russia, in 1976 suggested a mortality rate of almost 100%. However, the mortality rate of patients with inhalation anthrax in the United States in 2001 was only 45% (5 out of 11). REF: 733 OBJ: Level 1: Recall 13. What is the specimen of choice for cutaneous anthrax? a. Blood b. Spinal fluid c. Vesicular fluid from lesions d. Sputum C The specimen of choice for cutaneous anthrax is vesicular fluid from fresh vesicles. Also, swabs can be used to collect material from under the edge of the crust of the eschar. REF: 734 OBJ: Level 1: Recall 14. What is the specimen of choice for gastrointestinal and inhalation anthrax? a. Sputum b. Vesicular fluid from lesions c. Spinal fluid d. Blood D The specimen of choice for patients with gastrointestinal anthrax is blood, particularly a few days after exposure. The specimen of choice for patients with inhalation anthrax is also blood. REF: 734 OBJ: Level 1: Recall 15. A microbiologist is looking at a sheep blood agar (SBA) plate from a patient who might have been exposed to a biological agent. The colonies that are growing on the plate are nonhemolytic, large, have a ground-glass appearance, and look like a Medusa’s head. On Gram stain, the colonies are large gram-positive rods that seem to have central spores. What is the most probable organism? a. Bacillus anthracis b. Brucella mallei c. Burkholderia cepacia d. Yersinia pestis A In aerobic culture, B. anthracis will yield large (2- to 5-mm), nonhemolytic colonies on 5% SBA. Colony growth can be rapid, as little as 8 hours. Mature colonies have a ground-glass appearance; cells are characteristically large gram-positive bacilli, possibly showing endospore formation. The spores are central or subterminal and do not cause the bacterial cell to swell. The colony margins often have feathery projections coming from the margin, referred to as “Medusa-head” colonies. REF: 734 OBJ: Level 3: Synthesis 16. Organisms that have the following characteristics—aerobic growth, nonhemolytic colonies 2 to 5 m in diameter, catalase positive, nonmotile, large gram-positive bacilli recovered from lesions, blood, cerebrospinal fluid (CSF) or lymph nodes—can be presumptively identified as: a. Brucella mallei. b. Bacillus anthracis. c. Yersinia pestis. d. Burkholderia cepacia. B According to Centers for Disease Control and Prevention (CDC) protocols, a presumptive identification of B. anthracis can be made if an isolate has the following characteristics: aerobic growth, nonhemolytic colonies 2 to 5 mm in diameter, catalase positive, nonmotile, large gram-positive bacilli recovered from lesions, blood, CSF, or lymph nodes. REF: 734 OBJ: Level 2: Interpretation 17. What organism caused the disease known as the Black Death? a. Brucella mallei b. Bacillus anthracis c. Yersinia pestis d. Burkholderia cepacia C Throughout history, plague pandemics have demonstrated the efficacy of this organism as a weapon against humankind. The infection, commonly referred to as the Black Death, was decimating the Muslims, and in an effort to spread the disease to the Genoese in Kaffa, Tartar soldiers who had died of the Black Death were catapulted into the walled city. REF: 735 OBJ: Level 1: Recall 18. Yersinia pestis causes all the following except _____ plague. a. bubonic b. septicemic c. pneumonic d. meningococcal D Y. pestis causes bubonic plague, septicemic plague, and pneumonic plague. The infections can occur as a result of being bitten by an infested flea, handling contaminated materials, or inhaling aerosolized plague bacteria. REF: 736 OBJ: Level 1: Recall 19. What type of plague is the most common and results from the bite of a flea? a. Bubonic plague b. Septicemic plague c. Pneumonic plague d. Osmotic plague A Bubonic plague, the most common form of disease, results from the bite of a flea. It is characterized by fever, chills, headache, and malaise. The plague bacteria are transported to the local lymph nodes, most commonly the femoral, inguinal, or cervical nodes. As the bacteria multiply, the lymph node becomes inflamed and painful, forming the characteristic bubo with evident erythema. REF: 736 OBJ: Level 1: Recall 20. A microbiologist is looking at a set of plates from a seriously ill patient. The sheep blood agar (SBA) plate shows small, nonhemolytic colonies that have a fried egg appearance. On MacConkey, these organisms grow as a small, nonlactose fermenter. On Gram stain, this organism is a bipolar staining, plump gram-negative rod. What is the most probable organism? a. Brucella mallei b. Bacillus anthracis c. Yersinia pestis d. Burkholderia cepacia C Laboratory Response Network (LRN) protocols define a suspicious Yersinia pestis isolate as a bipolar staining gram-negative node that forms very small colonies after 24 hours of incubation at 37° C, although colonies grown at room temperature may be larger. Colonies of Y. pestis on SBA may grow slowly, and cultures may have to be held for up to 48 hours for good colony growth. Colonies are nonhemolytic and can have a fried egg appearance. On media selective for gram-negative bacilli, such as MacConkey agar, the organism will grow as small, nonlactose fermenting colonies. REF: 737 OBJ: Level 3: Synthesis 21. What disease is associated with rabbits? a. Francisella tularensis b. Bacillus anthracis c. Yersinia pestis d. Burkholderia cepacia A The most common mammal associated with tularemia in the United States is the rabbit. F. tularensis was first isolated and described in 1911, when it was found to be the cause of an outbreak in ground squirrels in Tulare County, California. REF: 737 OBJ: Level 1: Recall 22. What is the most common presentation for tularemia? a. Pneumonic tularemia b. Ulceroglandular tularemia c. Bubonic tularemia d. Septicemic tularemia B Depending on the source and route of infection, tularemia can have a number of clinical presentations. The most common presentation is ulceroglandular tularemia, which results from the inoculation of the organism into the dermis of the patient. REF: 738 OBJ: Level 1: Recall 23. When should a microbiologist consider Francisella tularensis? a. Tiny, gram-negative coccobacilli that do not grow well on chocolate or MacConkey’s and are biochemically inert b. Tiny, gram-negative coccus that grows well on blood agar c. Tiny, pleomorphic, poor-staining, gram-negative coccobacilli that do not grow well, if at all on blood agar d. None of the above C The microbiologist should consider F. tularensis when she or he finds a pleomorphic, poorly staining, gram-negative coccobacilli from a blood culture that does not grow well, if at all, on blood agar. REF: 739 OBJ: Level 2: Interpretation 24. All of the following are synonyms for brucellosis except _____ fever. a. Malta b. undulant c. Gibraltar d. relapsing D Synonyms for brucellosis include Malta fever, undulant fever, Mediterranean fever, Gibraltar fever, goat fever, Bang’s disease, and Cyprus fever. REF: 740 OBJ: Level 1: Recall 25. A microbiologist is looking at the blood culture plates taken from a woman who had ingested fresh, unpasteurized milk. The growth on the blood agar and chocolate agar showed small, circular, smooth, convex, nonpigmented, and nonhemolytic colonies. Gram stain revealed tiny gram-negative rods. The organism was catalase, oxidase, nitrate reduction, and urease positive, but showed a lack of motility. What is the most probable organism? a. Francisella tularensis b. Brucella abortus c. Yersinia pestis d. Burkholderia cepacia B Brucella colonies are small, circular, smooth, and convex, nonpigmented and nonhemolytic. On Gram stain, brucellae reveal tiny gram-negative coccobacilli. Results for a presumptive identification of Brucella spp. include the characteristics mentioned earlier for an organism that was isolated from an appropriate specimen, along with catalase, oxidase, nitrate reduction, urease positivity, and lack of motility. REF: 740 OBJ: Level 3: Synthesis 26. What organism causes glanders? a. Francisella tularensis b. Brucella abortus c. Yersinia pestis d. Burkholderia mallei D The genus Burkholderia contains two species considered potential agents of bioterrorism: B. mallei and B. pseudomallei. The disease caused by B. mallei is called glanders, and the disease caused by B. pseudomallei is called melioidosis. REF: 740 OBJ: Level 1: Recall 27. A microbiologist observes culture plates that have larger nonpigmented gray colonies at 24 hours that are indole-negative, nonmotile, catalase-positive, and resistant to polymyxin B disks. The Gram stain shows this is a gram-negative coccobacilli. What is the most probable organism? a. Francisella tularensis b. Brucella mallei c. Yersinia pestis d. Burkholderia cepacia B Gram-negative coccobacilli or small gram-negative bacilli with poor growth at 24 hours, forming larger nonpigmented gray colonies at 48 hours that are indole-negative, nonmotile, catalase-positive, and resistant to polymyxin B disks or colistin disks are presumptively identified as B. mallei and must be submitted to the state public health laboratory or a Laboratory Response Network (LRN) reference laboratory. REF: 742 OBJ: Level 3: Synthesis 28. What organism causes Q fever? a. Coxiella burnetii b. Brucella abortus c. Yersinia pestis d. Burkholderia cepacia A C. burnetii is the causative agent for the oddly named Q fever. The name of the disease was derived after an outbreak among slaughterhouse workers in Australia in 1935. The disease was called Query fever because no cause was found. REF: 742 OBJ: Level 1: Recall 29. What is characteristic of smallpox? a. The pustules penetrate deeply into the tissue b. Infections also occur on the palms and the soles of the feet c. The synchronous progression of the lesions d. All of the above D One of the most characteristic signs of smallpox, differentiating it from other viral fever/rashes, is the synchronous progression of the lesions—all lesions have nearly the same appearance. Also, lesions are more heavily concentrated on the extremities, as the virus prefers cooler body temperatures found in these locations. Another significant feature of smallpox infection is that the palms and soles are not spared, as they are with varicella. Vesicles continue to progress into pustules. The pustules are unique, in that they penetrate deeply into the tissue of the patient and are extremely turgid. REF: 743 OBJ: Level 2: Interpretation 30. How is smallpox diagnosed? a. Through a Centers for Disease Control and Prevention (CDC) algorithm b. By clinical signs c. Through cell culture d. All of the above D Detection and identification of smallpox virus is based on patient signs and symptoms as defined by the CDC’s Acute, Generalized Vesicular or Pustular Rash Protocol. REF: 745 OBJ: Level 1: Recall 31. Viral hemorrhagic fevers include all the following except: a. Ebola. b. Crimean-Congo. c. Lassa fever. d. black fever. D The hemorrhagic fever viruses include, but are not limited to, Ebola and Marburg viruses; Lassa fever virus; Crimean-Congo hemorrhagic fever virus; Rift Valley fever virus; several hantaviruses; and Dengue, yellow fever, and Omsk hemorrhagic fever viruses. REF: 745 OBJ: Level 1: Recall 32. Botulism toxin is a(n) _____ primarily produced by Clostridium botulinum. a. neurotoxin b. mucosal toxin c. enterotoxin d. endotoxin A Botulinum toxin is a neurotoxin primarily produced by C. botulinum, although other clostridia, including C. butyricum and C. baratii, can also produce this toxin. Seven different serotypes of the toxin, designated A through G, have been identified. The serotypes implicated in disease are A, B, and E. REF: 746 OBJ: Level 1: Recall 33. What is ricin? a. A potent biological toxin that disrupts native DNA strands b. A potent biological toxin that stops cell wall synthesis c. A potential biological toxin that inhibits protein synthesis d. All of the above C Ricin, from castor beans, is a potent biological toxin that inhibits protein synthesis. Clinical manifestations depend on the route of exposure. Ingestion of ricin typically leads to profuse vomiting and diarrhea followed by multisystem organ failure and possible death within 36 to 72 hours of exposure. Inhalation of ricin usually leads to respiratory distress, fever, and cough followed by the development of pulmonary edema, hypotension, respiratory failure, and possible death within 36 to 72 hours. REF: 747 OBJ: Level 1: Recall

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Chapter 29: Clinical Virology Answers Explained Chapter 29: Clinical Virology Test Bank MULTIPLE CHOICE 1. The genome of a virus is composed of: a. single-stranded DNA. b. RNA. c. double-stranded DNA. d. any of the above. D At a minimum, viruses contain a viral genome of either RNA or DNA and a protein coat—the capsid. The genome can be either double-stranded (ds) or single-stranded (ss). REF: 689 OBJ: Level 1: Recall 2. What requirements do viruses have for replication? a. They must be inside a living cell. b. They must be in an environment where all the necessary amino acids are present. c. They can use a dead cell to replicate. d. They need to be around dead, decaying flesh so that all the amino acids and enzymes are present. A Viruses are obligate intracellular parasites, meaning they must be inside a living cell to replicate. REF: 690 OBJ: Level 1: Recall 3. What is the correct sequence of viral infection, then destruction of a host cell? a. Attachment, penetration, replication, cell lysis b. Penetration, attachment, replication, cell lysis c. Replication, penetration, attachment, cell lysis d. Penetration, replication, attachment, cell lysis A The virus first attaches to the host cell. Next, the genome penetrates into the host cell. Once in the host cell, the virus uses the host cell machinery to replicate itself. Once replication is complete and the new viruses are assembled and ready to go, the cell is lysed to release the new viruses. REF: 690 OBJ: Level 2: Interpretation 4. When is the best time to collect a specimen for culture from a patient suspected of having a viral disease? a. 1 week after onset of symptoms b. 5 days after onset of symptoms c. Less than 3 days after onset of symptoms d. 2 weeks after onset of symptoms C Viral shedding is usually greatest during the early stages of infection, so the best specimens are those collected as early as possible. The sensitivity of viral culture may decrease rapidly 3 days after onset of symptoms. REF: 691 OBJ: Level 1: Recall 5. What is the composition of viral transport media? a. Amies media with charcoal b. Isotonic buffered saline with protein c. Cary-Blair d. Cooked meat broth B Several viral transport systems are commercially available. Most transport media consist of buffered isotonic solution with some type of protein, such as albumin, gelatin, or serum, to protect less stable viruses. REF: 691 OBJ: Level 1: Recall 6. What is an unsuitable storage temperature for viruses because it allows the development of ice crystals? a. 4 C b. –10 C c. –20 C d. –70 C C Specimens should not be stored at –20 C. This temperature facilitates the formation of ice crystals, which disrupts the host cells and results in significant loss of viral viability. REF: 691 OBJ: Level 1: Recall 7. All the following methods are used by the laboratory to diagnose viral infections except: a. chemiluminescence. b. direct detection. c. culture. d. serologic assays. A The laboratory uses three major methods to diagnose viral infections: direct detection of the virus in the clinical specimens, isolation of the virus in culture, and serologic assays to detect viral antibodies. REF: 692 OBJ: Level 1: Recall 8. Which of the following is the description of cytopathic effects in viral culture? a. The way viruses kill the infected host cell b. The visual changes produced in an infected cell by a virus c. The tears that the virus puts in an infected host cell’s membrane d. The way the virus lyses the infected cell after all the new virus particles are formed and ready to be released. B Many viruses produce characteristic visual changes in infected cells, referred to as cytopathic effect. REF: 692 OBJ: Level 1: Recall 9. All the following are direct methods for diagnosing viral infections except: a. indirect fluorescent antibody (IFA). b. direct fluorescent antibody (DFA). c. radioimmunoassay (RIA). d. enzyme immunoassay (EIA). C In DFA tests, host cells are fixed to a microscope slide and fluorescence-labeled antibodies are added. The IFA test for antigen detection can also be used. Many EIA tests for viral detection are commercially available; most are packaged as microtiter plate assays. REF: 692 OBJ: Level 1: Recall 10. All of the following methods are used as culture techniques to detect viruses except: a. cell culture. b. animal inoculation. c. embryonated eggs. d. media culture. D Traditionally, three methods are used for isolation of viruses in diagnostic virology: cell culture, animal inoculation, and embryonated eggs. REF: 693 OBJ: Level 1: Recall 11. Which of the following is the best description of a primary cell culture? a. It is a culture where tissue is removed from an animal, arranged in a monolayer, and in which very little cell division occurs. b. It is a culture that can divide, but passage is limited to 50 generations. c. It often has variable numbers of chromosomes and can be subcultured indefinitely. d. This describes the only cells the specimen will be plated on. A Primary cell cultures are obtained from tissue and removed from an animal. The tissue is finely minced and then treated with an enzyme such as trypsin to disperse further individual cells. The cells are then seeded onto a surface to form a monolayer. With primary cell lines, only minimal cell division occurs. REF: 694 OBJ: Level 1: Recall 12. Which of the following describes a diploid cell culture that is not a primary culture? a. It is a culture where tissue is removed from an animal, arranged in a monolayer, and very little cell division occurs. b. It is a culture that can divide, but passage is limited to 50 generations. c. It often has variable numbers of chromosomes and can be subcultured indefinitely. d. This describes the only cells the specimen will be plated on. B Diploid cell cultures can divide, but passage is limited to about 50 generations. With increasing passage, diploid cells become more insensitive to viral infection. REF: 694 OBJ: Level 1: Recall 13. Which of the following is the description of continuous cell cultures? a. It is a culture where tissue is removed from an animal, arranged in a monolayer, and in which very little cell division occurs. b. It is a culture that can divide, but passage is limited to 50 generations. c. It often has variable numbers of chromosomes and can be subcultured indefinitely. d. This describes the only cells the specimen will be plated on. C Continuous cell cultures have variable numbers of chromosomes and are capable of indefinite passage. Continuous cell lines are heteroploid, meaning they have an abnormal and a variable number of chromosomes that are not a multiple of the normal haploid number. REF: 694 OBJ: Level 1: Recall 14. What are giant multinucleated cells formed from cell fusion as a result of viral infection? a. Giant cells b. Macrophages c. Glial cells d. Syncytia D The respiratory viruses may not produce characteristic cytopathic effect. Respiratory syncytial virus (RSV) can produce a classic syncytial formation in Hep2 cells or even in monkey kidney cells. Syncytia are giant multinucleated cells formed from cell fusion as a result of virus infection. REF: 695 OBJ: Level 1: Recall 15. All of the following are common problems associated with using serologic methods to diagnose viral infections except: a. the host does not produce specific antibodies to viruses. b. serologic assays measure host response rather than directly detecting the virus. c. the antibody-producing capabilities of human hosts vary widely. d. the antibody level does not correlate with the activity level of the infection. A Viral serology provides limited information, and certain problems are inherent in the methods. First, serologic assays measure host response rather than directly detecting the virus. Second, the antibody-producing capabilities of human hosts vary widely and the antibody level does not necessarily correlate with the acuteness or acuity level of the infection. REF: 696 OBJ: Level 1: Recall 16. Adenoviruses produce all the following types of infections except: a. acute hemorrhagic cystitis. b. meningitis. c. acute respiratory distress. d. epidemic keratoconjunctivitis. B Although half of all adenovirus infections are asymptomatic, the virus causes about 10% of all pneumonia and 5% to 15% of all gastroenteritis in children. The virus causes upper respiratory tract infections, acute respiratory distress, epidemic keratoconjunctivitis, acute hemorrhagic cystitis, and pharyngoconjunctival fever. REF: 696 OBJ: Level 1: Recall 17. What type of genome do herpesviruses have? a. ssDNA b. ssRNA c. dsDNA d. Both dsDNA and ssRNA C The herpesviruses have a genome of linear dsDNA, an icosahedral capsid, an amorphous integument surrounding the capsid, and an outer envelope. REF: 697 OBJ: Level 1: Recall 18. What is another name for HHV-4? a. Varicella-zoster b. Cytomegalovirus c. Herpes simplex d. Epstein-Barr D Eight species of human herpesviruses (HHV) are currently known: herpes simplex virus type I (HSV-1); herpes simplex virus type 2 (HSV-2); varicella-zoster virus (VZV), also known as HHV-3; Epstein-Barr virus (EBV), also known as HHV-4; cytomegalovirus (CMV), also known as HHV-5; human herpesvirus 6 (HHV-6); human herpesvirus 7 (HHV-7); and human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma herpes virus (KSHV). REF: 697 OBJ: Level 1: Recall 19. What is another name for HHV-5? a. Varicella-zoster b. Cytomegalovirus c. Herpes simplex d. Epstein-Barr B Eight species of human herpesviruses (HHV) are currently known: herpes simplex virus type I (HSV-1); herpes simplex virus type 2 (HSV-2); varicella-zoster virus (VZV), also known as HHV-3; Epstein-Barr virus (EBV), also known as HHV-4; cytomegalovirus (CMV), also known as HHV-5; human herpesvirus 6 (HHV-6); human herpesvirus 7 (HHV-7), and human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma herpes virus (KSHV). REF: 697 OBJ: Level 1: Recall 20. What is another name for HHV-3? a. Varicella-zoster b. Cytomegalovirus c. Herpes simplex d. Epstein-Barr A Eight species of human herpesviruses (HHV) are currently known: herpes simplex virus type I (HSV-1); herpes simplex virus type 2 (HSV-2); varicella-zoster virus (VZV), also known as HHV-3; Epstein-Barr virus (EBV), also known as HHV-4; cytomegalovirus (CMV), also known as HHV-5; human herpesvirus 6 (HHV-6); human herpesvirus 7 (HHV-7), and human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma herpes virus (KSHV). REF: 697 OBJ: Level 1: Recall 21. What virus causes genital herpes? a. Human herpesvirus 6 (HHV-6) b. Cytomegalovirus (CMV) c. Herpes simplex virus type 2 (HSV-2 or HHV-2) d. Human herpesvirus (HHV-5) C Genital herpes are usually caused by HSV-2, although HSV-1 can cause as many as one third of the infections. REF: 697 OBJ: Level 1: Recall 22. A symptomatic congenital infection with cytomegalovirus (CMV) includes all the following symptoms except: a. hepatosplenomegaly. b. microcephaly. c. chorioretinitis. d. meningitis. D Congenital infections and infections in immunocompromised patients are often symptomatic and can be serious. Symptomatic congenital infection is characterized by petechiae, hepatosplenomegaly, microcephaly, and chorioretinitis. REF: 698 OBJ: Level 1: Recall 23. Complications of Epstein-Barr virus (EBV) infection include all the following except: a. acute glomerulonephritis. b. Reye’s syndrome. c. thrombocytopenia purpura with hemolytic anemia. d. splenic hemorrhage and rupture. A Complications of EBV infections are splenic hemorrhage and rupture, hepatitis, thrombocytopenia purpura with hemolytic anemia, Reye’s syndrome, encephalitis, and other neurologic syndromes. REF: 699 OBJ: Level 1: Recall 24. Which cancer is associated with Epstein-Barr virus (EBV)? a. Hepatocellular carcinoma b. Burkitt’s lymphoma c. Non-Hodgkin’s lymphoma d. T-cell leukemia B EBV has been associated with some cancers, including Burkitt’s lymphoma and nasopharyngeal carcinoma (NPC). Burkitt’s lymphoma is a malignant disease of the lymphoid tissue seen most commonly in African children. REF: 699 OBJ: Level 1: Recall 25. What disease does the varicella zoster virus (VZV) cause? a. Mumps b. Genital warts c. Chickenpox d. Rubella C VZV, in the genus Varicellovirus, spreads by droplet inhalation or direct contact with infectious lesions. The virus causes two different clinical manifestations: varicella (chickenpox) and zoster (shingles). REF: 700 OBJ: Level 1: Recall 26. What type of cancer is associated with human papilloma virus (HPV)? a. Lung b. Ovarian c. Skin d. Cervical D Although associated with the common wart, some of the HPV types are associated with cancer, including cervical cancer. REF: 701 OBJ: Level 1: Recall 27. What virus is the most common cause of viral gastroenteritis in infants and children? a. Rotavirus b. Influenzae virus c. Torovirus d. Respiratory syncytial virus (RSV) A Rotaviruses are the most common cause of viral gastroenteritis in infants and children. REF: 704 OBJ: Level 1: Recall 28. Which was the first arenavirus found to cause hemorrhagic fever? a. Ebola b. Malta c. Junin d. Marburg C The first of the arenaviruses found to cause hemorrhagic fever was the Junin virus, which causes Argentine hemorrhagic fever. REF: 704 OBJ: Level 1: Recall 29. All the following viruses cause hemorrhagic fever with renal syndrome (HFRS) except: a. Hantaan virus. b. Seoul virus. c. Dobrava virus. d. calicivirus. D The genus Hantavirus includes Hantaan virus, Seoul virus, Puumala virus, and Dobrava virus. These viruses cause a disease referred to as hemorrhagic fever with renal syndrome. REF: 705 OBJ: Level 1: Recall 30. What virus causes the Hantavirus pulmonary syndrome? a. Sin Nombre virus b. Dobrava virus c. Junin d. Lassa A The virus that occurred in mice and had infected the couple in New Mexico was ultimately characterized as a new Hantavirus; it was named Sin Nombre (“no name”) virus. The disease caused by this virus is now known as Hantavirus pulmonary syndrome. REF: 705 OBJ: Level 1: Recall 31. What virus is the most common cause of arboviral encephalitis in the world? a. Ebola b. Japanese encephalitis virus c. Venezuelan equine encephalitis virus d. Eastern equine encephalitis virus B Japanese encephalitis (JE) virus is a major cause of encephalitis in Asia and is the most common cause of arboviral encephalitis in the world. REF: 708 OBJ: Level 1: Recall 32. What is the most common flavivirus infection in the United States? a. West Nile virus b. Eastern equine encephalitis virus c. St. Louis encephalitis d. Rocky Mountain spotted fever C In the United States, the most common flavivirus is St. Louis encephalitis (SLE). Since the mid-1970s, an average of 193 cases of SLE has been reported annually in the United States. REF: 709 OBJ: Level 1: Recall 33. What virus causes the measles? a. Mumps b. Respiratory syncytial virus (RSV) c. Herpes virus 6 d. Rubeola virus D The measles virus (rubeola) is an enveloped virus classified in the genus Morbillivirus. REF: 711 OBJ: Level 1: Recall 34. What is the most common virus isolated from infants with lower respiratory infections and causes croup, bronchitis, bronchiolitis, and interstitial pneumonia? a. Respiratory syncytial virus (RSV) b. Lassa c. Rotavirus d. Norovirus A RSV is the most common virus isolated from infants with lower respiratory tract infections and causes croup, bronchitis, bronchiolitis, and interstitial pneumonia. REF: 712 OBJ: Level 2: Interpretation 35. What virus is the major cause of the common cold? a. Rotavirus b. Respiratory syncytial virus (RSV) c. Rhinovirus d. Norovirus C Rhinoviruses are the major cause of the common cold. REF: 714 OBJ: Level 1: Recall 36. What virus causes acquired immunodeficiency syndrome (AIDS)? a. Hepatitis C virus (HCV) b. Hepatitis B virus (HBV) c. Respiratory syncytial virus (RSV) d. Human immunodeficiency virus (HIV) D HIV causes AIDS. REF: 714 OBJ: Level 1: Recall 37. What viral genus causes rabies? a. Lyssavirus b. Lassa virus c. Marburg virus d. Calicivirus A Rabies is caused by several strains of viruses belonging to the genus Lyssavirus. REF: 716 OBJ: Level 1: Recall 38. Which virus is a bloodborne pathogen? a. Hepatitis A virus (HAV) b. Rabies c. Hepatitis C virus (HCV) d. Norovirus C Hepatitis C is spread through blood and blood products. REF: 693 OBJ: Level 1: Recall 39. What is a prion? a. A virion b. A viroid c. A proteinaceous infectious particle d. A lipopolysaccharide infectious particle C Prions, proteinaceous infectious particles, cause a group of diseases in mammals called transmissible spongiform encephalopathies. REF: 723 OBJ: Level 1: Recall 40. What infectious agent causes Creutzfeldt-Jakob disease, Kuru, and “mad cow” disease? a. Prion b. Bacteria c. Virus d. Parasite A Prions, proteinaceous infectious particles, cause a group of disease in mammals called transmissible spongiform encephalopathies (TSEs). Examples of TSEs include Kuru and Creutzfeldt-Jakob disease in humans, scrapie in sheep, bovine spongiform encephalopathy (BSE, or mad cow disease) in cattle, and chronic wasting disease in elk. REF: 723 OBJ: Level 2: Interpretation

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Chapter 28: Diagnostic Parasitology. Answers Explained Chapter 28: Diagnostic Parasitology Test Bank MULTIPLE CHOICE 1. A 4-year-old child has been complaining of a stomachache and has had intermittent episodes of diarrhea. Physical examination reveals an apparently healthy child with a mildly distended abdomen. Because of the diarrhea, a fecal sample is sent for culture and for O&P. What is the identity of that found in the child’s fecal sample? (Courtesy CDC Public Health Image Library (PHIL); a. Ascaris lumbricoides b. Strongyloides stercoralis c. Hookworm d. Schistosoma haematobium A The usual diagnostic stage is the egg. Fertile Ascaris eggs are oval, measure 45 to 75 by 35 to 50 m, and have thick hyaline walls surrounding a one-cell-stage embryo. Most eggs have a brown, bile-stained mammillated outer layer. CDC PHIL #410 REF: 676 OBJ: Level 3: Synthesis 2. A 15-year-old boy spent most of the summer at the northern Minnesota family cabin on a lake in a densely wooded area. After returning to school in the fall, he was frequently tired and listless with periods of fever and chills. A blood sample taken at the physician’s office revealed the following organism. The most likely identification is: (Courtesy CDC Public Health Image Library (PHIL); a. Plasmodium ovale. b. Babesia microti. c. Plasmodium malariae. d. Trypanosoma cruzi. B The diagnosis of babesiosis is made from a Wright-Giemsastained thin blood smear. The organisms appear as small, delicate, ring-form trophozoites, about 1 to 2 m, with a prominent chromatin dot and faintly staining cytoplasm. More mature trophozoites may appear as pyriform organisms in single, double, or the classic tetrad (Maltese cross) formation within the red blood cells. CDC PHIL #5944 REF: 656 OBJ: Level 3: Synthesis 3. What is the organism shown below? (Courtesy CDC Public Health Image Library (PHIL); a. Brugia malayi b. Loa loa c. Wuchereria bancrofti d. Onchocerca volvulus C Diagnosis of W. bancrofti should include the examination of a blood specimen obtained at night (10 p.m. to 2 a.m.) for the presence of microfilariae. The blood may be examined immediately for live microfilariae. If examined on a Wright’s-stained smear, the microfilariae of W. bancrofti are sheathed, and the nuclei do not extend to the tip of the tail. CDC PHIL #3010 REF: 681 OBJ: Level 3: Synthesis 4. A woman who just returned from a trip to Southeast Asia has signs of biliary obstruction, which is confirmed by CT scan. Due to her recent travel history, the physician orders an O&P examination before considering surgical intervention. The following element is found in her fecal sample. The most likely identity of this organism is: (Courtesy CDC Public Health Image Library (PHIL); a. Schistosoma mansoni. b. Opisthorchis sinensis. c. Fasciola hepatica. d. Heterophyes heterophyes. B The Chinese liver fluke, Clonorchis (Opisthorchis) sinensis, is geographically limited to the Far East, where dogs and cats serve as reservoir hosts. The adults live in the distal bile ducts. Repeated or heavy infections cause inflammation because of mechanical irritation, fever, diarrhea, pain, fibrotic changes, or obstruction of the bile duct. The diagnosis is made by finding the egg in a stool specimen. The egg is 29 to 35 m long, embryonated when passed, flash shaped, and operculated with prominent shoulders at the operculum and a knob at the opposite end. CDC PHIL #5248 REF: 665 OBJ: Level 3: Synthesis 5. A young man from rural Brazil is visiting family in the United States when he becomes ill with muscle pains, high fever, and hepatosplenomegaly. A blood sample taken in the emergency room reveals the following organism. The most likely identification of this organism is: (Courtesy CDC Public Health Image Library (PHIL); a. Leishmania donovani. b. Babesia microti. c. Plasmodium falciparum. d. Trypanosoma cruzi. D The primary diagnostic stage in the blood is the trypomastigote. It is an elongated structure 15 to 20 m long that often appears in a C or U shape. Individuals in the acute phase may be asymptomatic or have local symptoms including the presence of a chagoma (ulcerative skin lesion at the site of the insect bite) or a unilateral edema around the eye (Romaña sign) if the bite is on the ocular conjunctiva. Systemic manifestations include fever, lymphadenitis, hepatosplenomegaly, malaise, muscular pains, and diarrhea and vomiting. The latent phase can last 10 to 40 years after infection, but only about 30% to 40% of patients develop the chronic form of Chagas disease. CDC PHIL #3013 REF: 649 OBJ: Level 3: Synthesis 6. Five members of a family develop a sudden onset of watery diarrhea, nausea, vomiting, headache, and cramps. They go to the family physician who orders fecal cultures and complete ova and parasites (O&P) analysis. Each sample reveals the presence of organisms seen below. The most likely cause of the infection is: (Courtesy CDC Public Health Image Library (PHIL); a. Cryptosporidium parvum. b. Isospora belli. c. Cyclospora cayetanensis. d. Encephalitozoon intestinalis. A The recommended detection methods when Cryptosporidium infection is suspected are the modified Ziehl-Nielsen acid-fast stain and an immunofluorescent antibody test using a monoclonal antibody directed against Cryptosporidium. With the acid-fast stain, the organism stains as a bright red sphere that distinguishes it from yeasts, which stain green. CDC PHIL #5242 REF: 659 OBJ: Level 3: Synthesis 7. A housewife from the Great Lakes area comes to her family physician with fatigue and malaise. Blood tests show that she has enlarged but pale red blood cells (RBCs) (megaloblastic anemia) along with a vitamin B12 deficiency. Her history includes a dietary habit of making pickled fish, a family favorite. Because of this, an O&P is also requested and reveals the following parasite egg. What is the identity of this parasite? (Courtesy CDC Public Health Image Library (PHIL); a. Hymenolepis nana b. Taenia saginata c. Diphyllobothrium latum d. Taenia solium C D. latum, the fish tapeworm, is found worldwide in areas where the population eats pickled or raw fresh water fish. In the United States, it is primarily seen in the areas around the Great Lakes. The organism may cause a vitamin B12 deficiency, especially in persons of northern European descent, and long-term infection may lead to a megaloblastic anemia. The egg is operculated and yellow-brown, about 58 to 76 m by 40 to 50 m and has a small, knoblike protuberance at the end opposite the operculum. CDC PHIL #1541 REF: 668 OBJ: Level 3: Synthesis 8. The following organism was found in the fecal sample of a patient with diarrhea and elevated liver enzymes. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Entamoeba histolytica. b. E. hartmanni. c. Giardia lamblia. d. E. coli. A The size of the organism ranges from 10 to 50 m, averaging 15 to 25 m. The organism is refractile, and the characteristic “bull’s-eye” nucleus, consisting of a small central karyosome. Even, fine peripheral chromatin may be only slightly visible. The average size of the E. histolytica cyst is 10 to 20 m and may have one to four nuclei each with a small central karyosome and fine, evenly distributed peripheral chromatin. CDC PHIL #607 REF: 634 OBJ: Level 3: Synthesis 9. Several children at a daycare center are having trouble sleeping and are showing increasing signs of restlessness. Because one child was recently diagnosed with a parasite, the parents are informed that other children should be tested. The organism below is found during examination. This organism is: (Courtesy CDC Public Health Image Library (PHIL); a. Trichuris trichiura. b. Enterobius vermicularis. c. Ascaris lumbricoides. d. hookworm. B Enterobius vermicularis (pinworm) is a worldwide parasite commonly detected in children. Key risk factors for this infection are inadequate personal and/or community hygiene. The cellophane tape preparation is routinely used for detection of suspected pinworm infections. This procedure involves swabbing the child’s perianal area with a tongue blade covered with cellophane tape (sticky side out). The egg is oval, colorless, and slightly flattened on one side. It measures approximately 50 to 60 m by 20 to 30 m. CDC PHIL #5229 REF: 674 OBJ: Level 3: Synthesis 10. A recent emigrant from Somalia develops high fever, chills, and severe headache. Blood work on admission to the hospital reveals the following in his blood smear. This patient is most likely infected with: (Courtesy CDC Public Health Image Library (PHIL); a. Plasmodium ovale. b. P. malariae. c. P. falciparum. d. P. vivax. C P. falciparum invades RBCs of any age and, for this reason, often exhibits the highest parasitemia—reaching 50% in some cases. The ring forms of P. falciparum are more delicate than those of other species, often have two chromatin dots, and may show multiple ring forms in a single RBC. Gametocytes have a characteristic banana or crescent shape. CDC PHIL #5941 REF: 655 OBJ: Level 3: Synthesis 11. A farmer who raises sheep and cattle shows signs of jaundice. Along with elevated liver enzymes, he also has an elevated eosinophil count. A fecal sample for O&P shows the parasite form seen below. The organism causing this infection is: (Courtesy CDC Public Health Image Library (PHIL); a. Wuchereria bancrofti. b. Brugia malayi. c. Loa loa. d. Fasciola hepatica. D Fasciola hepatica, the sheep liver fluke, is seen in the major sheep-raising areas of the world, including parts of the southwestern United States. In addition, the organism is found in some cattle-raising areas. The unembryonated and operculated eggs of Fasciola hepatica are carried in the bile to the intestinal tract and are passed in the feces. The size range is 130 to 150 m by 60 to 90 m. They are virtually indistinguishable from eggs of F. buski. CDC PHIL #4846 REF: 664 OBJ: Level 3: Synthesis 12. A woman patient with history of travel to tropical Africa was noncompliant with her antimalarial medications. She now has a cyclical fever and paroxysm every 72 hours. The following organism is seen in her peripheral blood smear consistent with an infection caused by: (Courtesy CDC Public Health Image Library (PHIL); a. Plasmodium ovale. b. P. vivax. c. P. falciparum. d. P. malariae. D Plasmodium malariae usually invades older RBCs, perhaps accounting for the occasional darker appearance of the invaded RBC. The life cycle is characterized as quartan, with reproduction occurring every 72 hours and invasion of new RBCs every fourth day. The trophozoite of P. malariae is compact and may assume a characteristic “band” appearance, in which it stretches across the diameter of the RBCs. The mature schizont contains 6 to 12 merozoites with an average of 8. Merozoites may be arranged in a characteristic loose daisy petal arrangement around the clumped pigment. CDC PHIL #5130 REF: 650 OBJ: Level 3: Synthesis 13. An international male student from Egypt comes to the campus clinic complaining of blood in his urine. A urinalysis reveals the parasite seen below. This organism is: (Courtesy CDC Public Health Image Library (PHIL); a. Schistosoma mansoni. b. S. japonicum. c. S. haematobium. d. S. madurella. C S. haematobium, which is primarily found in the Nile Valley, the Mideast, and East Africa, lives in the veins surrounding the bladder. Diagnosis is made by finding embryonated eggs in the urine. S. haematobium eggs are elongated and 110 to 170 m by 40 to 70 m, and have a terminal spine. The best time to collect the eggs in urinary schistosomiasis is during peak excretion time in early afternoon (12 p.m. to 2 p.m.). CDC PHIL #4843 REF: 666 OBJ: Level 3: Synthesis 14. A patient with recent history of travel to the Philippines has bloody diarrhea. An O&P sample shows the following parasite egg. What is this called? (Courtesy CDC Public Health Image Library (PHIL); a. Schistosoma mansoni b. S. japonicum c. S. haematobium d. S. madurella B S. japonicum, which is commonly found in the Far East, including Japan, China, and the Philippines, lives in venules of the small intestine. The egg spines cause trauma to the tissues and walls of the vessels during the early stage of acute infections and can result in diarrhea. S. japonicum eggs are round and 60 to 95 m by 40 to 60 m; they have a small, curved, rudimentary spine. CDC PHIL #4842 REF: 666 OBJ: Level 3: Synthesis 15. A patient who has traveled to the Puerto Rico comes to clinic with a history of diarrhea for the past 2 weeks. A fecal sample collected for O&P shows the following parasite. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Schistosoma mansoni. b. S. japonicum. c. S. haematobium. d. S. madurella. A S. mansoni, which is most commonly found in Africa, parts of South America, the West Indies, and Puerto Rico, lives in venules of the mesentery and large intestines. The egg of S. mansoni is yellowish, elongated and 115 to 175 m by 45 to 75 m, and has a prominent lateral spine. CDC PHIL #4841 REF: 666 OBJ: Level 3: Synthesis 16. A patient finds a small ribbon-like piece in his stool sample and reports this to his physician. The physician orders a fecal O&P analysis that reveals the following egg in the sample. The most likely identity of this parasite is: (Courtesy CDC Public Health Image Library (PHIL); a. Hymenolepis nana. b. Taenia spp. c. Diphyllobothrium latum. d. Paragonimus westermani. B Laboratory diagnosis of Taenia spp. infection can be made by finding the egg, scolex, or proglottid in the feces. The egg is yellow-brown and surrounded by a thick wall with radial striations; it measures 30 to 43 m. The egg is embryonated with a six-hook oncosphere when passed in the feces. Eggs of this species are indistinguishable and must be reported as “Taenia spp.” eggs. CDC PHIL #906 REF: 669 OBJ: Level 3: Synthesis 17. A patient with a history of eating wild game comes to the physician with a history of diarrhea over the past 3 weeks. In addition he complains of fever, muscular pain and tenderness, headache, and general weakness. The patient also has a significant eosinophilia. A biopsy of a nodular area on his forearm is seen in the image below. This is consistent with a diagnosis of: (Courtesy CDC Public Health Image Library (PHIL); a. Leishmania donovani. b. Wuchereria bancrofti. c. Trichinella spiralis. d. Loa loa. C Trichinosis is the infection of muscle tissue with the larval form of T. spiralis, a helminth whose adult stages live in the human intestine. Humans acquire the infection by eating undercooked meat, particularly pork that contains the larval forms. In recent years ingestion of wild game has led to infection by other species of Trichinella. Because it is difficult to recover adults or larvae in a stool sample, the diagnosis is often based on clinical symptoms and the patient’s history. Biopsy of muscle tissue and identification of encapsulated, coiled larva is the definitive diagnostic method. CDC PHIL #10142 REF: 679 OBJ: Level 3: Synthesis 18. A young man who returned a week ago from a family vacation to Kenya, develops a high fever and delirium. Although he was compliant with his antimalarial medications, a blood sample is taken to rule out malaria. The laboratory scientist sees the following on the blood smear. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Trypanosoma brucei. b. Leishmania donovani. c. Wuchereria bancrofti. d. Loa loa. A Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense are the causative agents of human African trypanosomiasis, commonly called sleeping sickness, which is seen primarily in central Africa. The diagnostic stage of trypanosomes in humans is the trypomastigote, which is usually seen in a Wright’s-stained blood smear. The trypomastigote is 15 to 20 m, with a single large nucleus and a posterior kinetoplast to which is attached the flagellum of the undulating membrane. CDC PHIL #3017 REF: 647 OBJ: Level 3: Synthesis 19. A patient comes to the emergency room stating that he has fever and chills every 48 hours. The patient has a history of travel to Central America in the past month and did not take any preventative measures against malaria. A complete blood count (CBC) shows the following RBC inclusions. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Plasmodium malariae. b. P. ovale. c. P. falciparum. d. P. vivax. D P. vivax has the widest geographic distribution and is the one most likely to be found in temperate climates. A fine pink stippling, known as Schüffner’s stippling, may be present in the cell. The young trophozoite of P. vivax is characterized by its ameboid appearance; by maturity, it usually fills the red blood cell, and golden brown malarial pigment is present. CDC PHIL #5927 REF: 650 OBJ: Level 3: Synthesis 20. When a request is submitted to examine a blood sample for malaria, which of the following procedures should be performed? a. A thick smear for maximum detection and to determine morphology b. A PVA trichrome-stained blood smear c. A Giemsa thick blood smear preparation for maximum detection and a thin smear for speciation d. A formalin-ethyl acetate concentration for detection and a thin smear for speciation C History of travel to an endemic area and the presence of classic clinical symptoms, including the malarial paroxysm of fever and chills, should alert a health care provider to request Giemsa-stained thick and thin smears for malaria. The thick smear is used to detect malarial parasites; however, distortions of parasite morphology and the lack of intact RBCs require that a thin smear be examined to identify the species. REF: 653 OBJ: Level 1: Recall

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Chapter 27: Medically Significant Fungi. All Answers Chapter 27: Medically Significant Fungi Test Bank MULTIPLE CHOICE 1. This organism was isolated from a sinus aspirate of a patient with chronic sinusitis and respiratory allergies. Identify the organism shown below. (Courtesy CDC Public Health Image Library (PHIL); a. Candida albicans b. Alternaria spp. c. Mucor spp. d. Pseudallescheria boydii B Although these isolates may be recovered from virtually any source, they are primarily implicated in chronic fungal sinusitis. Patients are often misdiagnosed and treated for an extended time for bacterial sinusitis. Microscopic evaluation reveals short conidiophores bearing conidia in chains that lengthen in an acropetal fashion. Multicelled conidia have angular cross walls and taper toward the distal end. Alternaria spp. are dematiaceous, rapidly growing fungi with colonies ranging from shades of gray, to brown, to black. CDC PHIL #3962 REF: 610 OBJ: Level 3: Synthesis 2. A bone marrow transplant patient develops an abrupt fever with respiratory distress. Despite treatment with antifungal medications, the patient dies on the fifth day. The following organism was isolated from both sputum and blood cultures. Identify the organism shown below. (Courtesy CDC Public Health Image Library (PHIL); a. Rhizopus spp. b. Mucor spp. c. Histoplasma capsulatum d. Aspergillus spp. D Aspergillus spp. are the second most isolated fungus after Candida spp. Neutropenia is the single most predictive factor for developing aspergillosis. Aspergillus spp. are the most frequent cause of disease in the bone marrow transplant recipient in addition to other cancer and transplant patients. Infection is initiated following inhalation of fungal conidia. In the lung air spaces, conidia germinate and invade the tissue. Within a few days, the patient develops a severe fever that fails to respond to antifungal therapy. CDC PHIL #300 REF: 608 OBJ: Level 3: Synthesis 3. A graduate student returning from a month-long fieldwork experience in South America develops a dark nodular lesion on his left hand. Microscopic examination of the nodule reveals dark, coinlike inclusions. The following organism grows in culture. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Cladosporium spp. b. Candida spp. c. Coccidioides immitis. d. Cryptococcus neoformans. A An infrequent cause of disease, Cladosporium is primarily recovered as a laboratory contaminant. Infections are typically confined to the sinuses or following traumatic inoculation. Cladosporium forms brown, to olive, to black hyphae and conidia. Conidiophores are erect and may branch into several conidiogenous cells. This disease is diagnosed by the presence of characteristic lesions accompanied by microscopic sclerotic bodies, often referred to as copper pennies because of their shape and staining properties in tissue sections. CDC PHIL #3214 REF: 611 OBJ: Level 3: Synthesis 4. A Seattle woman with HIV complains of headaches and also displays some memory loss. Because of her history, the physician collects cerebrospinal fluid (CSF) and sends it to the laboratory for analysis. The following image is seen using India ink stain. What is the most likely identification of this organism? (Courtesy CDC Public Health Image Library (PHIL); a. Coccidioides immitis b. Blastomyces dermatitidis c. Cryptococcus gattii d. Candida albicans C Cryptococcus spp. are important causes of meningitis, pulmonary disease, and septicemia. C. neoformans, the most notable pathogen in this genus, has become a major cause of opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). Cryptococcus spp. express a capsule that produces the characteristic mucoid colony. The capsule can be detected surrounding the budding yeast in spinal fluid with the aid of India ink or Nigrosin. Cryptococcus gattii is an emerging pathogen, particularly in the Pacific Northwest of the United States. CDC PHIL #3771 REF: 612 OBJ: Level 3: Synthesis 5. The following organism was isolated from an immunocompetent patient with chronic sinusitis. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Mucor spp. b. Rhizopus spp. c. Alternaria spp. d. Curvularia spp. D Curvularia isolates are most often implicated in chronic sinusitis in immunocompetent patients. Multicelled conidia are produced on sympodial conidiophores. This genus is easier to identify because of the frequently crescent-shaped conidia with three to five cells of unequal size, with an enlarged central cell. CDC PHIL 4270 REF: 611 OBJ: Level 3: Synthesis 6. A patient returning from a trip to tropical Africa comes to his physician noting scaly patches of skin along the waistband, which are lighter in color than his normal skin. A skin scraping reveals budding yeast and short septate hyphal elements, with some branching present. This organism, shown below, is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Malassezia furfur. b. Trichophyton schoenleinii. c. Microsporum audouinii. d. Trichophyton rubrum. A The M. furfur complex causes tinea versicolor, a disease characterized by patchy lesions or scaling of varying pigmentation. M. furfur may be identified by visualizing skin scrapings from characteristic lesions in a potassium hydroxide preparation or by observing yellow fluorescence with a Wood’s lamp upon examination of the infected body site. Microscopic examination of the direct smear in potassium hydroxide (KOH) preparations reveals budding yeasts, approximately 4 to 8 m, along with septate, sometimes branched, hyphal elements. The microscopic appearance has gained M. furfur the term “the spaghetti and meatballs” fungus. CDC PHIL #2916 REF: 594 OBJ: Level 3: Synthesis 7. A patient who wears long-term contact lenses comes to her physician after noting a small spot on her cornea. Collection of the lesion for culture produced a fast-growing mold with a slight pink color on the surface. Microscopic review showed the following organism. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Sporothrix schenckii. b. Fusarium spp. c. Mucor spp. d. Geotrichum spp. B Fusarium is frequently seen in mycotic dermatitis. In bone marrow transplant patients, mortality from infections caused by the fusaria approaches 100%. Normally, abundant macroconidia with fewer microconidia are produced on vegetative hyphae. Macroconidia are banana- or canoe-shaped and are formed singly, in small clusters, or they may cluster together in mats termed sporodochia. CDC PHIL #4011 REF: 609 OBJ: Level 3: Synthesis 8. The following organism was isolated from the sputum culture of a cancer chemotherapy patient. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Mucor spp. b. Penicillium spp. c. Geotrichum spp. d. Alternaria spp. C Geotrichum has been implicated in pulmonary disease in immunocompromised patients. Microscopic evaluation reveals abundant arthroconidia formed from the vegetative hyphae that occur either single or branched. CDC PHIL #3056 REF: 609 OBJ: Level 3: Synthesis 9. A recreational cave explorer develops a productive cough and fever. A sputum culture is sent to the laboratory for bacterial, fungal, and mycobacterial cultures. A white mold colony develops on Sabouraud’s agar after 5 days at 22° C. Identify the organism shown below. (Courtesy CDC Public Health Image Library (PHIL); a. Histoplasma capsulatum b. Toxoplasma gondii c. Microsporum tonsurus d. Paracoccidioides brasiliensis A Histoplasmosis is acquired by the inhalation of the microconidia of Histoplasma capsulatum var. capsulatum. Histoplasmosis is also known as reticuloendothelial cytomycosis, cave disease, spelunker’s disease, and Darling’s disease. H. capsulatum grows as a white to brownish mold. Early growth of the mycelial culture produces round to pyriform microconidia measuring 2 to 5 m. As the colony matures, large echinulate or tuberculate macroconidia, a characteristic of the species, are formed. CDC PHIL #10958 REF: 604 OBJ: Level 3: Synthesis 10. A young boy develops itchy, dry scaly lesions on his leg with a raised, red, outer edge. A culture of the lesion reveals the following organism in a lactophenol cotton blue stain. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Trichophyton spp. b. Mucor spp. c. Microsporum canis. d. Blastomyces dermatitidis. C Each ringworm lesion is the result of a local inoculation of the skin with the etiologic agent. Lesions enlarge with time, usually with most inflammation occurring at the advancing edge of the lesion. Macroconidia are spindle shaped with echinulate, thick walls; measuring 12 to 25 m by 35 to 100 m and have 3 to 15 cells. The tapering, sometimes elongated, spiny distal ends of macroconidia are key features that distinguish this species. CDC PHIL #15472 REF: 597 OBJ: Level 3: Synthesis 11. The following organism is isolated from a case of tinea capitis. The organism grew rapidly producing tan mold colonies. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Trichophyton rubrum. b. Epidermophyton audouinii. c. Fonsecaea compacta. d. Microsporum gypseum. D The fusiform, moderately thick-walled conidia typical of M. gypseum can have as many as six cells. Colonies that form tan to buff conidial masses are typical of fresh isolates, but this species tends to develop pleomorphic tufts of white, sterile hyphae in aging cultures and after serial transfers. CDC PHIL # 15079 REF: 597 OBJ: Level 3: Synthesis 12. This organism was isolated from a diabetic patient with a sinus infection. The mold was extremely fast growing with a dirty white surface. Microscopic observation revealed wide aseptate hyphae without rhizoids. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Mucor spp. b. Microsporum spp. c. Sporothrix schenckii. d. Malassezia furfur. A Mucor spp. have been implicated in rhinocerebral zygomycosis in addition to disseminated disease. Mucor spp. are commonly isolated from the environment worldwide. Rhizoids, typical of some Mucorales, are not found in Mucor spp. Mucor spp. grow rapidly and form cottony, dirty white colonies that become mousy-brown to gray with age. CDC PHIL # 3961 REF: 607 OBJ: Level 3: Synthesis 13. A student working for the summer at a plant nursery has a nodular lesion on his forearm that develops a draining tract. The following organism is isolated from the culture at 22C. Identify the organism shown below. (Courtesy CDC Public Health Image Library (PHIL); a. Trichosporon boydii b. Sporothrix schenckii c. Trichophyton rubrum d. Microsporum canis B Sporothrix schenckii commonly presents as a progressive lymphocutaneous infection beginning with a single draining lesion and progressing along the limbs via the lymphatic system forming multiple draining lesions. In temperate countries such as France, Canada, and the United States, most cases of sporotrichosis are associated with gardening, particularly with exposure to rose thorns (rose-handler’s disease) and sphagnum moss. Microscopic examination from culture reveals thin, delicate hyphae bearing conidia developing in a rosette pattern at the end of delicate conidiophores. CDC PHIL #10603 REF: 594 OBJ: Level 3: Synthesis 14. A patient with thickened and discolored nails was diagnosed with onychomycosis. A scraping of the nail was sent for culture. Microscopic analysis of the mold colony growth revealed the following morphology. The most likely identity of this organism is: (Courtesy CDC Public Health Image Library (PHIL); a. Microsporum canis. b. Sporothrix schenckii. c. Aspergillus fumigatus. d. Trichophyton mentagrophytes. D Onychomycosis, infection of the nails, is most often caused by dermatophytes but also may be the result of infection by other fungi. Nails become thick, discolored, and flakey. Some common agents that infect the nails are Trichophyton rubrum, T. mentagrophytes, and T. tonsurans, as well as Epidermophyton floccosum. Trichophyton mentagrophytes makes both microconidia and macroconidia. Microconidia are primarily globose but may appear tear-shaped. Microconidia are found primarily in clusters described as grapelike or “engrape.” Macroconidia are thin walled, smooth, and cigar shaped, with four to five cells separated by parallel cross walls. CDC PHIL # 15105 REF: 597 OBJ: Level 3: Synthesis 15. After returning from a vacation trip to the Amazon River delta in Brazil, a man notices a white dirtlike substance on his axilla hair that does not wash off in the shower. His health care provider samples the hairs and sends them to the laboratory for culture. Straw-colored yeastlike colonies show the following microscopic morphology. This is most consistent with an identification of: (Courtesy CDC Public Health Image Library (PHIL); a. Malassezia furfur. b. Trichosporon spp. c. Microsporum audouinii. d. Trichophyton rubrum. B Trichosporon spp. produce both arthroconidia and blastoconidia. White piedra occurs on the hair shaft and is characterized by a soft mycelial mat surrounding hair of the scalp, face, and pubic region. White piedra is endemic in tropical areas of South America, the Far East, and the Pacific. CDC PHIL #3936 REF: 595 OBJ: Level 2: Interpretation 16. A young man notices a darkened area of skin on the palm of his hand. It seems to be increasing in size over the past 2 weeks. His health care provider collects a skin scraping for microscopic examination, which shows septate hyphal elements and budding cells. This organism is most likely: (Courtesy CDC Public Health Image Library (PHIL); a. Malassezia furfur. b. Mucor spp. c. Hortaea werneckii. d. Microsporum canis. C Tinea nigra, characterized by brown to black nonscaly macules that occur most often on the palms of the hands and soles of the feet, is caused by H. werneckii. The disease is endemic in the tropical areas of Central and South America, Africa, and Asia. Diagnosis of tinea nigra can be made by direct examination of skin scrapings placed in 10% to 20% KOH. Microscopic examination shows septate hyphal elements and budding cells. CDC PHIL #4206 REF: 596 OBJ: Level 3: Synthesis 17. All of the following are examples of dimorphic fungi except: a. Candida albicans. b. Coccidioides immitis. c. Histoplasma capsulatum. d. Sporothrix schenckii. A These dimorphic fungi include a mould phase and either a yeast or spherule phase. The yeast or tissue state is seen in vivo or when the organism is grown at 37 C with increased CO2. The mould phase is seen when the organism is grown at room temperature. Thermally dimorphic fungal species associated with human disease include Blastomyces dermatitidis, C. immitis, H. capsulatum var. capsulatum, Paracoccidioides brasiliensis, S. schenckii, and Penicillium marneffei. REF: 592 OBJ: Level 1: Recall 18. A patient with very pale patches on his arms and legs is examined at his physician’s office. His physician orders a fungal culture. The fungus shows a spaghetti-and-meatball appearance on the direct smear. What organism is it? a. Microsporum canis b. Malassezia furfur c. Trichophyton rubrum d. Epidermophyton floccosum B Microscopic examination of the direct smear in potassium hydroxide (KOH) preparations reveals budding yeasts, approximately 4 to 8 m, along with septate, sometimes branched, hyphal elements. This microscopic appearance has gained M. furfur the term spaghetti and meatballs fungus. REF: 595 OBJ: Level 3: Synthesis 19. What is the causative agent of black piedra? a. Microsporum canis b. Trichosporon beigelii c. Piedraia hortae d. Sporothrix schenckii C P. hortae is the causative agent of black piedra, an infection that occurs on the hairs of the scalp. REF: 595 OBJ: Level 1: Recall 20. What is the causative agent of tinea nigra? a. Microsporum canis b. Trichosporon beigelii c. Piedraia hortae d. Hortaea werneckii D Tinea nigra, characterized by brown to black nonscaly macules that occur most often on the palms of the hands and soles of the feet, is caused by P. werneckii. REF: 596 OBJ: Level 1: Recall 21. All of the following organisms cause cutaneous mycoses except: a. Sporothrix schenckii. b. Trichophyton beigelii. c. Microsporum canis. d. Epidermophyton floccosum. A Three genera of fungi, Trichophyton, Microsporum, and Epidermophyton, are etiologic agents of dermatophytosis. Species within these genera are keratinophilic—that is, they are adapted to grow on hair, nails, and cutaneous layers of skin that contain the scleroprotein keratin. REF: 594 OBJ: Level 1: Recall 22. Chromoblastomycosis is caused by all the following organisms except: a. Fonsecaea compacta. b. Penicillium marneffei. c. Fonsecaea pedrosoi. d. Phialophora verrucosa. B Chromoblastomycosis is caused by several infectious agents, namely Fonsecaea compacta, F. pedrosoi, Phialophora verrucosa, Cladophialophora carrionii, and Rhinocladiella aquaspera. REF: 598 OBJ: Level 1: Recall 23. What organism is found in the San Joaquin Valley region of California? a. Sporothrix schenckii b. Penicillium marneffei c. Coccidioides immitis d. Paracoccidioides brasiliensis C Although morphologically identical, genetic evaluation has differentiated between C. immitis and C. posadasii. It appears that the species can be traced to specific geographical locations. C. immitis is encountered in the San Joaquin Valley region of California, whereas C. posadasii is found in the desert southwest of the United States, Mexico, and South America. REF: 604 OBJ: Level 2: Interpretation 24. What organism frequently presents in fungus balls? a. Fonsecaea compacta b. Penicillium marneffei c. F. pedrosoi d. Aspergillus fumigatus D Neutropenia is the single most predictive factor for developing aspergillosis. Another frequent presentation is “fungus balls” in the lungs of agricultural workers who routinely are in contact with fungal conidia from environmental sources. REF: 608 OBJ: Level 1: Recall 25. What organism is one of the primary opportunistic infections in AIDS patients? a. Pneumocystis jirovecii b. Hortaea werneckii c. Coccidioides immitis d. Paracoccidioides brasiliensis A Since the early 1980s, P. jirovecii (nee P. carinii) has remained one of the primary opportunistic infections found in patients with AIDS. REF: 623 OBJ: Level 1: Recall 26. For potassium hydroxide (KOH) to work properly, what is done to speed up the dissolution of the keratin and skin layers? a. Mix gently. b. Let the slide sit for 30 minutes before reading. c. Heat gently, then cool. d. Let sit under an ultraviolet light for 20 minutes. C In this procedure, a drop of the KOH preparation is added to a slide. Nail scrapings, hair, skin scales, or thin scales of tissue are added to the drop, and a coverslip is added. The slide is then gently heated and allowed to cool for approximately 15 minutes. The KOH breaks down the keratin and skin layers so that observers can more easily visualize any fungi that may be present in the specimen. REF: 617 OBJ: Level 2: Interpretation

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Chapter 26: Mycobacterium tuberculosis and Nontuberculous Mycobacteria. All Answers Chapter 26: Mycobacterium tuberculosis and Nontuberculous Mycobacteria Test Bank MULTIPLE CHOICE 1. What is the optimum culture incubation time for most mycobacteria associated with human disease? a. 2 to 6 weeks b. 1 to 2 weeks c. 5 to 7 days d. 3 to 5 days A Most mycobacteria associated with disease require 2 to 6 weeks of incubation on complex media at specific optimum temperatures. REF: 564 OBJ: Level 1: Recall 2. What Mycobacterium spp. fails to grow in vitro? a. Mycobacterium tuberculosis b. M. leprae c. M. avium d. M. marinum B One mycobacterium that is pathogenic for humans, M. leprae, fails to grow in vitro. REF: 564 OBJ: Level 1: Recall 3. All of the following are traditional characteristics used to identify mycobacteria except: a. rate of growth. b. colony morphology. c. gram stain results. d. pigmentation. C Rate of growth, colony morphology, pigmentation, nutritional requirements, optimum incubation temperature, and biochemical test results are traditional characteristics used to differentiate species within the genus Mycobacterium. REF: 573 OBJ: Level 1: Recall 4. How are mycobacterial infections transmitted? a. By blood b. By fomites c. By sexual contact d. By air D The serious nature of tuberculosis disease and the usual airborne route of infection require that special safety precautions be used by anyone handling mycobacterial specimens. REF: 573 OBJ: Level 1: Recall 5. When designing a mycobacterial laboratory, the designers should build in all the following engineering controls to keep the workers safe except: a. inside air vents to outside. b. nonrecirculating ventilation system. c. negative air pressure. d. separate room from main laboratory. A Laboratory design and ventilation play an important role in mycobacteriology laboratory safety. Ideally, the mycobacteriology laboratory should be separate from the remainder of the laboratory and should have a nonrecirculating ventilation system. The area in which specimens and cultures are processed should have negative air pressure in relation to other areas; that is, the airflow should be from clean areas, such as corridors, into less clean areas. REF: 573 OBJ: Level 1: Recall 6. What is the single most important piece of equipment in a mycobacterial laboratory? a. Ultraviolet lights b. Covered centrifuge c. Biological safety cabinet d. CO2 incubator C Because the route of infection by mycobacteria is primarily through inhalation, it is essential that the dispersal of organisms into the air be minimized and that inhalation of airborne bacilli be avoided. The biological safety cabinet is the single most important piece of equipment in a mycobacteriology laboratory. REF: 573 OBJ: Level 1: Recall 7. What is the recommended contact time for most disinfectants in a mycobacteriology laboratory? a. 5 minutes b. 10 to 30 minutes c. 10 minutes d. 60 minutes B The following disinfectants are used in the mycobacterial laboratories to disinfect working surfaces: Phenol soap, 10 to 30 minutes; sodium hypochlorite, 10 to 30 minutes; formaldehyde, 30 minutes; and phenol, 10 to 30 minutes. REF: 573 OBJ: Level 1: Recall 8. What is the purpose of the digestion-decontamination processing of specimens submitted for mycobacterial culture? a. To release all bacteria in the sample b. To make the specimen easier to plate c. To allow chemical decontaminants to kill nonmycobacterial organisms d. To liquefy the outer cell wall of the mycobacteria so that they will grow faster C The purposes of the digestion-decontamination process are to liquefy the sample through digestion of the proteinaceous material and to allow the chemical decontaminating agent to contact and kill the nonmycobacterial organisms. REF: 576 OBJ: Level 1: Recall 9. Decontaminating agents used in the decontamination-digestion process include all of the following except: a. sodium hydroxide. b. N-acetyl-1-cysteine. c. benzalkonium chloride. d. hydrochloric acid. D Sodium hydroxide, N-acetyl-1-cysteine, benzalkonium chloride, and oxalic acid are used as decontaminating chemicals in the digestion-decontamination process. REF: 577 OBJ: Level 1: Recall 10. All of these stains are commonly used to visualize mycobacteria on a smear except: a. Ziehl-Neelsen. b. Kinyoun. c. auramine. d. acridine orange. D The conventional acid-fast staining methods, Ziehl-Neelsen and Kinyoun stains, use carbolfuchsin as the primary stain, acid-alcohol as a decolorizing agent, and a methylene blue counterstain. The Ziehl-Neelsen staining procedure involves the application of heat with the carbolfuchsin stain, whereas the Kinyoun acid-fast stain is a cold stain. The auramine or auramine-rhodamine fluorochrome stains are more sensitive than the carbolfuchsin stains. REF: 577 OBJ: Level 1: Recall 11. What media are recommended for routine culturing of specimens for the recovery of acid-fast bacilli? a. Löwenstein-Jensen and liquid-based media b. Middlebrook 7H10 and cooked meat broth c. Sabouraud dextrose and LIM broth d. Thiosulfate-citrate-bile salts-sucrose (TCBS) and thioglycollate broth A Because some isolates do not grow on a particular agar and each type of culture medium offers certain advantages, a combination of culture media is generally recommended for primary isolation. The use of a solid-based medium, such as Löwenstein-Jensen (LJ) medium, in combination with a liquid-based medium is recommended for routine culturing of specimens for the recovery of AFB. REF: 578 OBJ: Level 1: Recall 12. What constituent of Löwenstein-Jensen (LJ) medium is added to suppress the growth of gram-positives? a. Carbolfuchsin b. Malachite green c. Gentian purple d. Mercurochrome B The basic ingredients in an inspissated egg medium, such as LJ, Petragnani, and American Thoracic Society (ATS) media, are fresh whole eggs, potato flour, and glycerol, with slight variations in defined salts, milk, and potato flour. Each contains malachite green to suppress the growth of gram-positive bacteria. REF: 578 OBJ: Level 1: Recall 13. Middlebrook 7H10 and 7H11 media are enriched with all of the following except: a. oleic acid. b. bovine albumin. c. heme. d. beef catalase. C Serum albumin agar media, such as Middlebrook 7H10 and 7H11 agars, are prepared from a basal medium of defined salts, vitamins, cofactors, glycerol, malachite green, and agar combined with an enrichment consisting of oleic acid, bovine albumin, glucose, and beef catalase. REF: 578 OBJ: Level 1: Recall 14. What is the most sensitive and rapid primary isolation liquid media for Mycobacterium spp.? a. Thioglycollate b. Cooked meat c. 5% NaCl broth d. Middlebrook 7H12 D The most sensitive and rapid primary isolation liquid media are Middlebrook 7H12 and 7H13 (BACTEC 12 B and 13 B). REF: 579 OBJ: Level 1: Recall 15. How long does it take to detect Mycobacterium spp. with the BACTEC method? a. Less than 2 weeks b. 3 weeks c. 4 weeks d. 6 weeks A With the BACTEC method, mycobacteria may be detected in clinical specimens in less than 2 weeks. In general, the time required for isolation and identification of Mycobacterium tuberculosis is reduced from 6 weeks to 3 weeks. REF: 579 OBJ: Level 1: Recall 16. What type of media is recommended for the recovery of Mycobacterium haemophilum? a. Sheep blood agar (SBA) b. Chocolate c. Polysaccharide egg antigen (PEA) d. Löwenstein-Jensen (LJ) B A chocolate agar plate should be included in the primary isolation media for skin and other body surface specimens for the recovery of M. haemophilum, which requires ferric ammonium citrate or hemin for growth. Alternatively, hemin (X) strips or disks used for the identification of Haemophilus spp. can be placed on Middlebrook agar plates. REF: 580 OBJ: Level 1: Recall 17. A microbiologist is checking the mycobacteria cultures. She notices growth in one tube of Löwenstein-Jensen (LJ) that is a buff color, rough, and seems arranged in a cord. It has taken these organisms 4 weeks to grow. What is the most probable organism? a. Mycobacterium leprae b. M. avium c. M. tuberculosis d. M. marinum C Colonies of M. tuberculosis that are rough also exhibit a prominent patterned texture referred to as cording; this texture is the result of tight cohesion of the bacilli. M. tuberculosis has a generation time of 20 to 22 hours and generally grows in culture in approximately 26 days. REF: 581 OBJ: Level 3: Synthesis 18. What are photochromogens? a. Species that produce carotene pigment upon exposure to light b. Species that produce pigment in the light or the dark c. Species whose colonies remain buff colored after exposure to light d. Species whose colonies fluoresce under ultraviolet light A Species that produce carotene pigment upon exposure to light are photochromogens. Color may range from pale yellow to orange. REF: 581 OBJ: Level 1: Recall 19. What are scotochromogens? a. Species that produce carotene pigment upon exposure to light b. Species that produce pigment in the light or the dark c. Species whose colonies remain buff colored after exposure to light d. Species whose colonies fluoresce under ultraviolet light B Species that produce pigment in the light or the dark are scotochromogens. Growth temperature may influence the photoreactive characteristics of a species. REF: 581 OBJ: Level 1: Recall 20. What are nonchromogens? a. Species that produce carotene pigment upon exposure to light b. Species that produce pigment in the light or the dark c. Species whose colonies remain buff colored after exposure to light d. Species whose colonies fluoresce under ultraviolet light C Some Mycobacterium spp., such as M. tuberculosis, are nonchromogenic or nonphotochromogenic. These colonies are a buff color and are nonphotoreactive; exposure to light does not induce pigment formation. REF: 581 OBJ: Level 1: Recall 21. All of the following are biochemical tests for the identification of Mycobacterium spp. except: a. niacin. b. nitrate. c. catalase. d. PYR. D The biochemical tests are based on the enzymes the organisms possess, the substances that their metabolisms produce, and the inhibition of growth on exposure to selected biochemicals: niacin, nitrate reduction, catalase, hydrolysis of Tween 80, iron uptake, arylsulfatase, pyrazinamidase, tellurite reduction, urease, NAP inhibition test, TCH inhibition tests, sodium chloride tolerance, and growth on MacConkey agar. REF: 581 OBJ: Level 1: Recall 22. All of the following are biochemical tests for the identification of Mycobacterium spp. except: a. gelatin liquefaction. b. hydrolysis of Tween 80. c. iron uptake. d. arylsulfatase. A The biochemical tests are based on the enzymes the organisms possess, the substances that their metabolisms produce, and the inhibition of growth on exposure to selected biochemicals: niacin, nitrate reduction, catalase, hydrolysis of Tween 80, iron uptake, arylsulfatase, pyrazinamidase, tellurite reduction, urease, NAP inhibition test, TCH inhibition test, sodium chloride tolerance, and growth on MacConkey agar. REF: 583 OBJ: Level 1: Recall 23. What component of mycobacteria is used for identification in nucleic acid hybridization assays? a. DNA b. Ribosomal RNA c. Transfer RNA d. Messenger RNA B These tests are nonisotopically labeled probes specific to the mycobacterial ribosomal RNA. The ribosomal RNA is released from the cell after sonification. REF: 585 OBJ: Level 1: Recall 24. How has the treatment of mycobacterial disease changed in light of the multidrug-resistant strains of mycobacteria that are being isolated? a. Antibiotic therapy is started sooner in the course of the disease. b. More powerful antibiotics are used to treat mycobacterial disease. c. Combinations of three or four drugs are used instead of a single drug. d. Patients are hospitalized for the duration of their disease. C Random drug resistance has a good chance of developing when only one antimycobacterial agent is used or if the patient is on multidrug therapy and fails to complete the course of medication. Therefore, the use of three or more drugs to treat mycobacterial infections has become common. REF: 567 OBJ: Level 2: Interpretation 25. The Centers for Disease Control and Prevention (CDC) recommends all the following drugs for the treatment of Mycobacterium tuberculosis except: a. ethambutol. b. isoniazid. c. rifampin. d. ciprofloxacin. D The CDC currently recommends that, when isolated, M. tuberculosis be tested for susceptibility to isoniazid, rifampin, ethambutol, and streptomycin. REF: 586 OBJ: Level 1: Recall 26. What classifies an organism as a multidrug-resistant Mycobacterium tuberculosis? a. Organisms resistant to at least isoniazid and rifampin b. Organisms resistant to isoniazid, rifampin, ethambutol, and streptomycin c. Organisms resistant to streptomycin and rifampin d. Organisms resistant to ciprofloxacin and imipenem A Multidrug-resistant M. tuberculosis denotes the presence of M. tuberculosis resistant to at least isoniazid and rifampin. REF: 567 OBJ: Level 1: Recall 27. What is the antigen used in the purified protein derivative (PPD) skin test? a. A purified protein from the nucleus of Mycobacterium tuberculosis b. A purified piece of DNA from M. tuberculosis c. A purified protein from the cell wall of M. tuberculosis d. A piece of ribosomal RNA from M. tuberculosis C Purified protein derivative of the cell wall extracted from culture-grown M. tuberculosis is used as the antigen for the PPD test. REF: 587 OBJ: Level 1: Recall 28. A child visits his doctor because he has had a fever and a nonproductive cough. The child is also short of breath. The doctor orders a routine sputum culture and an acid-fast bacillus (AFB) culture and smear. The smear shows red organisms arranged in ropes. What is the most probable cause of this child’s fever and cough? a. Mycobacterium leprae b. M. avium c. M. intracellulare d. M. tuberculosis D Clinical diagnosis of primary tuberculosis is usually limited to signs and symptoms, and a positive tuberculin skin test. Children may demonstrate a nonproductive cough and fever with or without shortness of breath; these symptoms are unusual in adults. REF: 565 OBJ: Level 3: Synthesis 29. If a person has had tuberculosis during his or her lifetime, how likely is it that the person will get the disease again? a. 5% to 15% b. 20% to 25% c. 1% d. 50% A The risk of reactivation of tuberculosis is about 3.3% during the first year after a positive tuberculin skin test and a total of 5% to 15% thereafter. REF: 565 OBJ: Level 1: Recall 30. All of the following are common extrapulmonary infection sites for tuberculosis except: a. kidneys. b. gastrointestinal. c. liver. d. spleen. B The most common sites of spread of M. tuberculosis are the spleen, liver, lungs, bone marrow, kidney, adrenal gland, and eyes, usually in that order of occurrence. Other forms of extrapulmonary TB include pleural, lymphadenitis, gastrointestinal, skeletal, meningeal, peritoneal, and genitourinary infections. REF: 566 OBJ: Level 1: Recall 31. A 35-year-old man travels on a multidestination vacation over a 2 month period, including lengthy stops in tropical Africa and Southeast Asia. Six weeks after returning come home to the United States, he develops a productive cough, fatigue, weight loss, low-grade fever, and night sweats. What disease should the physician consider as a result of his travel history? a. Streptococcal pneumonia b. Primary atypical pneumonia c. Tuberculosis (TB) d. Pneumonia caused by gram-negative rods C The symptoms for TB include cough, fatigue, weight loss, low-grade fever, and night sweats. In 2011, the World Health Organization estimated that 12 million people worldwide suffered from TB. However, as many as one third of the world’s population might be harboring the bacteria. Currently, in the United States more cases are associated with foreign-born individuals from endemic areas than with U.S.–born persons. REF: 568 OBJ: Level 3: Synthesis 32. A patient with Hodgkin’s disease is feeling bad, so he pays a visit to his physician. The physician’s clinical examination reveals submandibular lymphadenitis, subcutaneous nodules, painful swellings, ulcers progressing to abscesses, and draining fistulas. What organism is probably producing these symptoms? a. Mycobacterium tuberculosis b. M. avium c. M. gordonae d. M. haemophilum D The rare infections associated with M. haemophilum occur primarily in patients who are immunocompromised. Cases have been reported in patients with Hodgkin’s disease and acquired immunodeficiency syndrome (AIDS). Submandibular lymphadenitis, subcutaneous nodules, painful swellings, ulcers progressing to abscesses, and draining fistulas are often the clinical manifestations. REF: 569 OBJ: Level 3: Synthesis 33. This disease is slowly progressive, malignant, and, if untreated, life threatening. It is characterized by skin lesions and progressive, symmetric nerve damage. Lesions of the mucous membranes of the nose may lead to destruction of the cartilaginous septum, resulting in nasal and facial deformities. What disease is this? a. Hansen’s disease b. Extrapulmonary tuberculosis c. Non–Mycobacterium tuberculosis pulmonary disease d. M. xenopi A Patients with lepromatous leprosy do not produce an effective cell-mediated immune (CMI) response. Hansen’s disease is slowly progressive, malignant, and, if untreated, life threatening. It is characterized by skin lesions and progressive, symmetric nerve damage. Lesions of the mucous membranes of the nose may lead to destruction of the cartilaginous septum, resulting in nasal and facial deformities. Despite its reputation, Hansen’s disease is not considered a highly contagious disease. REF: 572 OBJ: Level 3: Synthesis 34. A sputum culture from a patient in Texas has colonies that grow buff colored colonies in approximately 4 weeks. After exposure to light, the colonies turn intense yellow. This isolate is most likely: a. M. scrofulaceum. b. M. kansasii. c. M. fortuitum. d. M. xenopi. B Mycobacterium kansasii is second to MAC as the cause of NTM lung disease. In the United States, most cases of M. kansasii infections have been reported from the southern states of Texas, Louisiana, and Florida; from Illinois and Missouri in the Midwest; and from California. Colonies are photochromogenic, meaning that they form a pigment when exposed to light but are nonpigmented in the dark. REF: 568 OBJ: Level 3: Synthesis

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