Name............................................................................................................. Group C 12.11.2008.
1. A 2-year-old child has a high fever and is irritable. He has a stiff neck. Gram stain smear of spinal fluid reveals gram-negative, small pleomorphic coccobacillary organisms. What is the most appropriate procedure to follow in order to reach an etiological diagnosis?
a) Culture the spinal fluid in chocolate agar and identify the organism by growth factors
b) Culture the spinal fluid in mannitol-salt agar
c) Perform a catalase test of the isolated organism
d) Perform a latex agglutination test to detect the specific antibody in the spinal fluid
2. A hyperemic edema of the larynx and epiglottis that rapidly leads to respiratory obstruction in young children is most likely to be caused by which of the following organisms?
a) Haemophilus hemolyticus
b) H. influenzae b
c) K. pneumoniae
d) Neisseria meningitidis
3. B. abortus, one of the three species causing brucellosis, a possible bioterrorism agent, is best descibed by which of the following statements?
a) Manifests different biochemical and physiologic characteristics, depending on growth temperature and causes a spectrum of human disease, most commonly mesenteric lymphadenitis
b) Pits agar, grows both in carbon dioxide and under anaerobic conditions and is part of the normal oral cavity flora
c) Typically infects cattle, requires 5 to 10% carbon dioxide for growth and is inhibited by the dye thionine
d) Typically is found in infected animal bites in humans and cause hemorrhagic septicemia in animals
4. F. tularensis is the bacterium that causes tularemia, a disease not uncommonly seen in hunters. Which one of the following statements best characterizes this bacterium?
a) It produces a toxin that blocks protein synthesis in an infected cell and carries a lytic bacteriophage that produces the genetic information for toxin production
b) It secretes an erythogenic toxin that causes the characteristic signs of scarlet fever
c) It secretes an exotoxin that has been called “verotoxin” and “Shiga-like toxin”; infection is mediated by specific attachment to mucosal membranes
d) It requires cysteine for growth
5. Bordetella pertussis, called whooping cough, can best be detected by which of the following procedures?
a) Culture of respiratory secretions in HeLa cells after centrifugation of the inoculated tubes
b) Culture of respiratory secretions on Regan-Lowe agar
c) Direct microscopy of sputum by Gram stain
d) Fluorescent antibody detection of the organism in sputum
6. E. coli O157 H7 is a newsworthy microorganism that has been isolated from foods, with increasing frequency. Its characteristic biology is best described by one of the following statement:
a) It produces protein toxin that cause severe spasmatic cough usually in children.
b) It secretes an erythrogenic toxin that causes the characteristic signs of scarlet fever
c) It secretes an exotoxin that has been called „Shiga - like toxin” and „verotoxin”
d) It produces a toxin that blocks protein synthesis in an infected cell
7. Which of the following tests would be most useful to differentiate Shigella flexneri from Shigella boydii?
a) fermentation of lactose
b) motility
c) agglutination in specific antisera
d) production of H2S
8. Local lesions induced by Salmonella typhi are localized mainly in:
a) large intestine
b) small intestine
c) kidneys
d) liver
9. Which of the following is most likely to cause urinary tract infections:
a) Salmonella typhi
b) Streptococcus pneumoniae
c) Shigella flexneri
d) Escherichia coli
10. Diarrhea in travelers is commonly cause by:
a) Proteus vulgaris
b) Klebsiella pneumoniae
c) ETEC (enterotoxigenic E. coli)
d) EPEC (enteropathogenic E. coli)