Portage Microbiology Exam #5 Questions and Answers Already Passed

Portage Microbiology Exam #5 Questions and Answers Already Passed Define the concept of universal precautions (short answer) Universal precautions means any and all samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials List at lease 3 observations a researcher would be sure to note while assessing and unknown microbial sample (short answer) Need to note: 1. Size and shape 2. Any observable motility 3. Gram status (positive or negative) While observing an unknown sample of limited amounts, a researcher must determine the following observations: 1) the presence of any motility and 2) its Gram status using the same sample- the liquid sample cannot be divided. Which would you determine first and why? (short answer) You must determine motility before determining Gram status. Motility requires a wet mount, while gram staining requires heat fixing the sample. If one were to begin with the gram stain, the heat fixation process would kill the organism, making any observations regarding motility impossible. The correct approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the same liquid culture can be heat fixed and gram stained. A facultative anaerobe is a microorganism capable of growth under what conditions? (short answer) A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen) conditions True or False: The Lancefield groups are used to subdivide antigenic groups of alpha-hemolytic Streptococcus False. The Lancefield groups are used to subdivide beta-hemolytic strep The distinctions for Lancefield subgroups lie in its: (select all that apply) A. Catalase activity B. Carbohydrate composition of antigens C. Hemolytic activity D. All of the above B. Carbohydrate composition of antigens Rheumatic fever displays _____ hemolytic activity and occurs when _____ if left untreated Beta: strep. Pharyngitis True or False: Under most circumstances, staphylococcus can be found in ~80% of human population where it remains non-symptomatic False. Staphylococcus in only found (non-symptomatic) in ~30% of the human population Define commensal bacteria (short answer) (know term and definition first) The bacterium neither harms nor benefits from the host from which it obtains nutrients How can staphylococcus be differentially tested? (short answer) Staphylococcus species are capable of growth in the presence of bile salts Symptoms of folliculitis Pus-filled lesions on skin or hair Symptoms of scalded-skin syndrome Ruptured-pustules; treated with penicilin Symptoms of Impetigo Childhood skin disease near mouth/nose Symptoms of conjuctivitis Infections of thin, transparent scieral tissue Symptoms of ophthalmia neonatorum Infection occurs at time of birth True or False: the causative agent of conjunctivitis can be either bacterial or viral True. There are bacterial (staph) and viral forms of conjunctivitis, both resulting in the inflammation of the conjunctiva and 'pink eye' True or False: Tuberculosis is best identified by a gram stain False. Mycobacterium show poor Gram staining and show be screened via an acid-fast stain True or False: You can become infected with TB simply by sharing a drink with someone who is currently infected with TB False. As per the CDC guidelines, simply shaking someone's hand, sharing a drink, or even kissing someone cannot spread TB Identify the disease based on the following (select all that apply): It is a small, acid-fast rod usually remaining asymptomatic for up to 20 years. It affects the skin, nerves, upper respiratory tract and eyes of infected individuals A. Tuberculosis B. Leprosy C. Scalded-skin syndrome D. Hansen's disease E. Bacterial conjunctivitis B & D (Hansen's disease is another name for leprosy) True or False: Only directly ingesting the pre-formed clostridium toxin (neither the bacteria nor its spores) will cause disease in adults True While visiting his grandparents, a 10-year old child has green beans for dinner that were harvested from his grandparents' garden and canned the previous year. Severe illness sets in and the child is taken to the hospital. Botulism is suspected, but what form? (short answer) Foodbourne botulism. The child is too old (> 6 months) to be considered and wounds were not present. The green beans were likely improperly canned and under the low-acidic, anaerobic conditions, bacterial growth was encouraged True or False: Although there is no cure for tetanus, it can be prevented through vaccination True. There is not cure for tetanus, however tetanus is entirely preventable through vaccination Describe the symptoms and treatment regimen for someone infected with Clostridium pefringens (short answer) Clostridium perfringens presents with muscle necrosis, swelling of infected areas, fever, and intense gas production. Treatment entails removal of all infected tissue, often resulting in amputation of the affected areas, in conjunction with heavy antibiotic therpies Why does the alpha toxin (perfringolysin) produced during an infection of gas gangrene cause cell death? (short answer) The toxin perforates the membrane. It forms pores in the plasma membrane of host cells resulting in uncontrolled ion fluxes and eventually cell lysis and death You develop a fever, chills, and pneumonia after recently using a warm midst vaporizer in an attempt to open your sinuses. What bacterial disease would a doctor suspect is causing your symptoms? Would the doctor suspect you contracted it from touching (potentially) contaminated doorknobs? (short answer) Legionnaires. No- legionella cannot be spread simply by direct contact between two people. Legionella can only be transmitted through droplets small enough to be breathed in True or False: Bubonic plague is often characterized by painfully swollen lymph nodes True Which form of the plague is highly virulent? What does it target? Pneumonic