Microorganisms and Disease
Pseudomembraneous colitis is

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

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Microorganisms and Disease
The influenza vaccine is administered each year because

it is a polysaccharide vaccine that does not confer long-term protection
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

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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

cleavage of rRNA that results in disruption of ribosome function
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

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Microorganisms and Disease
The "A" subunit of diphtheria toxin

lysis macrophages with the release of cytokines
binds host cell receptors found on heart cells
cause ADP ribosylation of a factor involved in protein synthesis
forms cAMP that leads to fluid accumulation

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Microorganisms and Disease
Which of the following characteristic of the Rotavirus was important for the construction of the Rotashield vaccine?

The possession of a segmented RNA genome
A limited number of capsule types
The ability of the Rotavirus to be transmitted faster
The ability of monkey Rotavirus strains to cause serious illness (diarrhea) in human beings

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