Microbiology Board Exam Graded A+

Microbiology Board Exam Graded A+ Which of the following is more likely to be diagnostic of an acute infection? t iter of 2 followed by a convalescent titer of 16 Diagnosis of group A streptococci infection is indicated by the presence of: A total acute antibody Anti-DNase The rapid plasma reagin assay for syphilis does not need to be read microscopically because the antigen is: Complexed with charcoal The VDRL test for syphilis is classified as a: One cause of a false positive VDRL test is: Flocculation reaction Systemic lupus erythematosus Which of the following is an example of a treponemal antigen test used for the diagnosis of syphilis? FTA-ABS A serum sample is positive for HBsAg. This result indicates that the person from whom the serum was taken: Has either active or chronic hepatitis B infection Patient serum is mixed with a suspension of guinea pig antigen. When the sample is then mixed with horse red blood cells, agglutination occurs. This is suggestive of an infection caused by: Barr virus The first serologic marker to appear in patients with acute hepatitis B virus infection is: Why does vaccination against hepatitis B virus also prevent hepatitis D virus infections? requires the host to be concurrently infected with HBV Anti-HAV: Nonreactive Anti-HBc: Reactive Anti-HBs: Nonreactive HBsAg: Reactive Epstein HBsAg HDV HBeAg: Reactive Anti-HCV: Nonreactive CMV IgG titer: 20 EBV IgM titer: 80 Chronic HBV infection Acute EBV infection What is the next step after a reactive ELISA for HIV? Enterococcus Repeat the ELISA on the same sample A test for the hydrolysis of esculin in the presence of bile is especially useful in identifying species of the genus: The organism associated with a disease characterized by the presence of a psuedomembrane in the throat and the production of exotoxin that is absorbed into the bloodstream with a lethal effect is: Corynebacterium diphtheriae Enterotoxin produced by Staphylococcus aureus is responsible for causing: Enterocolitis Abiotrophia, formerly known as nutritionally variant streptococci, will not grow on routine blood or chocolate stars because they are deficient in: Pyridoxal/Vitamin B6 Exfoliatin produced by S. aureus is responsible for causing: S. pyogenes can be presumptively identified using a: Scalded skin syndrome PYR disk A GPC that is catalase positive, nonmotile, lysostaphin resistant and modified oxidase positive is best identified as a member of the genus: Micrococcus Nocardia asteroides infections in humans characteristically produce: Erysipelothrix infections in humans characteristically produce: Draining cutaneous sinuses Pathology at the point of entrance of the organism What organism can be presumptively identified by the CAMP test? S. agalactiae S. saprophyticus is the cause of: Urinary tract infections GPB with translucent beta-hemolytic colonies on SPA Listeria monocytogenes The etiologic agent most commonly associated with septicemia and meningitis of newborns is: agalactiae S. Which of the following is the most commonly isolated species of Bacillus in opportunistic infections? B. cereus Loeffler's serum medium is recommended for the cultivation of: Cornyebacterium diphtheriae On Tinsdale agar, colonies of C. diphtheriae are characterized by the observance of: on the culture medium surrounded by brown halos Black colonies Precipitates of diphtheria toxin and antitoxin formed in agar gels are an in vitro means for detecting toxigenic strains of C. diphtheriae. The name of this test is: Elek test The etiologic agent of the disease erysipelas is: S. pyogenes S. aureus when present could most likely be recovered from a stool sample if the primary plating medium included: Phenylethyl alcohol A common member of the normal flora of the upper respiratory tract is: Streptococci obtain all their energy from the fermentation of sugars to: Streptococci are unable to synthesize the enzyme: Catalase Viridans streptococcus Lactic acid The beta hemolysis produced by group A streptococcus seen on the surface of a sheep blood agar plate is primarily the result of: Streptolysin S When an infection due to streptomyces is suspected, isolates can be separated from most other bacteria by: Incubating the culture at 25 C The production of H2S is one characteristic used to differentiate which of the aerobic GPB? Erysipelothrix Test tube brush motility at room temperature Rhodococcus equi Listeria monocytogenes A former species of Corynebacterium pathogenic for swine, horses and cattle which grows pale pink colonies. Which of the following is not appropriate when describing S. pneumoniae? Nocardia can be differentiated from Actinomyces based on: Bile resistant Nocardia being catalase positive Enterococcus faecium is characteristically: salt A negative PYR test is demonstrated by: Able to grow in the presence of high concentrations of Viridans streptococci A gram stain of a sputum specimen from a patient with a suspected case of lobar pneumonia reveals many WBCs and many GPC, which are primarily diplococci. Which of the following is true? optochin test should be performed on the culture isolate An