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
cleavage of rRNA that results in disruption of ribosome function
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
Type III secretion systems are used to inject "effector" proteins directly into a host cell. Salmonella uses a type III secretion system to help the pathogen to

survive within macrophages
activate T cells to proliferate and secrete cytokines
secrete LT (heat labile toxin) and ST (heat stable toxin) into the lumen of the intestine
survive the acid pH of the stomach

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

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