Microorganisms and Disease
Pseudomembraneous colitis is

caused by a spore-forming bacterium
caused by a gram-positive bacterium
precipitated by the use of certain antibiotics
All of these

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Microorganisms and Disease
Cholera toxin is an A-B type toxin in which the B portions bind to a receptor on a host cell and the A portion enters the cell to cause

ADP ribosylation of guanylate cyclase that stimulates production of cGMP
ADP ribosylation of adenylate cyclase that stops production of cAMP
ADP ribosylation of a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP
cleavage of rRNA that results in disruption of ribosome function

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Microorganisms and Disease
The influenza vaccine is administered each year because

the vaccine is sufficiently toxic to make it necessary to administer only a small amount at any one time
None of these
mutations in the viral hemagglutinin may allow the virus to evade the immune response elicited by previous vaccines
it is a polysaccharide vaccine that does not confer long-term protection

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Microorganisms and Disease
Which of the following is common in the disease caused by Coryne-bacterium diphtheriae and Bacillus anthracis?

Both organisms cause skin and respiratory tract infections
The most serious disease symptoms are the direct result of toxin action
Both organisms are gram-positive spore formers
Diphtheria toxin and edema toxin are ADP ribosylating toxins

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