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
survive the acid pH of the stomach
secrete LT (heat labile toxin) and ST (heat stable toxin) into the lumen of the intestine

ANSWER DOWNLOAD EXAMIANS APP

Microorganisms and Disease
What is common in catheters and ventilators?

They bypass important defenses of the body
They predispose patients to viral rather than bacterial infections
Bacteria responsible for associated infections are usually susceptible to antibiotics
They are used primarily in neonatal intensive care units

ANSWER DOWNLOAD EXAMIANS APP

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 a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP
ADP ribosylation of adenylate cyclase that stops production of cAMP
ADP ribosylation of guanylate cyclase that stimulates production of cGMP

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Microorganisms and Disease