Microorganisms and Disease
Plastic implants can pose a serious nosocomial infection problem because

All of these
infected implants usually have to be surgically removed
phagocytes have trouble engulfing bacteria embedded in a biofilm
phagocytes have trouble moving on the plastic surface

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Microorganisms and Disease
The "A" subunit of diphtheria toxin

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

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Microorganisms and Disease
Prontosil is

an effective antibacterial when used in in-vitro cultures
an effective antibacterial both in animals as well as in in-vitro cultures
not used as an antibacterial agent
an effective antibacterial when used in animals

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

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