A traveler has watery diarrhea that looks like rice water, with rapid dehydration. Which toxin mechanism explains the diarrhea?
Answer and explanation
Correct answer: A. Permanent activation of Gs, raising cyclic AMP
- Step 1: Rice-water diarrhea points to Vibrio cholerae. Step 2. Cholera toxin ADP-ribosylates the Gs protein, which keeps cyclic AMP high and drives chloride secretion. Answer: permanent activation of Gs. Why not the others: inhibition of 60S is Shiga toxin, inactivation of elongation factor 2 is diphtheria toxin and SNARE cleavage is botulinum or tetanus toxin.
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