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Part II: Clinical Bacteriology
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The main reason why some bacteria are anaerobes (i.e., they cannot grow in the presence of oxygen) is because:
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(A) they do not have sufficient catalase and superoxide dismutase.
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(B) they have too much ferrous ion that is oxidized to ferric ion in the presence of oxygen.
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(C) they have unusual mitochondria that cannot function in the presence of oxygen.
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(D) transcription of the gene for the pilus protein is repressed in the presence of oxygen.
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Which one of the following sets consists of bacteria that are both anaerobes?
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(A) Actinomyces israelii and Serratia marcescens
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(B) Campylobacter jejuni and Vibrio cholerae
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(C) Clostridium perfringens and Bacteroides fragilis
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(D) Mycobacterium tuberculosis and Pseudomonas aeruginosa
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(E) Mycoplasma pneumoniae and Corynebacterium diphtheriae
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You’re in the clinical laboratory looking at a Gram stain when the laboratory technician comes up to you and says, “I think your patient has Staph epi [short for Staphylococcus epidermidis] bacteremia.” Which one of the following sets of results did the tech find with the organism recovered from the blood culture?
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(A) Gram-positive cocci in chains, catalase-positive, coagulase-positive
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(B) Gram-positive cocci in chains, catalase-negative, coagulase-negative
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(C) Gram-positive cocci in clusters, catalase-positive, coagulase-negative
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(D) Gram-positive cocci in clusters, catalase-negative, coagulase-positive
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(E) Gram-positive diplococci, catalase-negative, coagulase-positive
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Superantigen production by Staphylococcus aureus is involved in the pathogenesis of which one of the following diseases?
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(C) Scalded skin syndrome
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Which one of the following is the virulence factor produced by Staphylococcus aureus that prevents the activation of complement and thereby reduces opsonization by C3b?
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The main reason why methicillin-resistant Staphylococcus ...