Culture media for isolation of S.typhi from stool is
A. blood plate
B. SS plate
C. chocolate plate
D. common plate
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Both staphylococcal food poisoning and salmonellosis can be acquired by eating contaminated food. After eating contaminated food, the time required for the onset of staphylococcal food poisoning is shorter than that for salmonellosis because
A. Staphylococcus aureus grows more rapidly than Salmonella enteritidis serotypes.
B. cells of Salmonella must reach the bloodstream before symptoms of gastrointestinal irritation are experienced.
C. foods that contain Salmonella are usually eaten raw.
D. staphylococcal food poisoning is due to the presence of an exotoxin that forms in the food before it is eaten, but salmonellosis requires the colonization and growth of the bacteria in the intestine.
Salmonella is normally
A. a lactose fermenter
B. non motile
C. indole positive
D. H2S positive
Heat-labile toxin of ETEC acts by which of the following mechanisms?
Attachment
B. Activation of adenylyl cyclase
C. Aggregative adherence
D. Ribosomal dysfunction
Long-term carriage and shedding is most likely to occur after gastrointestinal infection with which of the following species?
A. Escherichia coli O157:H7
B. Shigella dysenteriae
C. Vibrio cholerae
D. Salmonella typhi
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