Bacteriology USMLE Step 1 Practice Question
A 34-year-old man returns from South Asia presenting with profuse watery diarrhea, severe dehydration, and abdominal cramping for 3 days. Vital signs show BP 90/60 mmHg, HR 118/min, RR 20/min, and temperature 37.2°C. Stool culture grows a curved gram-negative rod that is oxidase-positive with elevated stool osmolar gap. He denies bloody stools. Which of the following best describes the mechanism of the enterotoxin produced by this organism?
Answer choices
- AInactivation of the 60S ribosomal subunit
- BCleavage of SNARE proteins in inhibitory neurons
- CCleavage of desmoglein in the superficial epidermis
- DADP ribosylation of Gs causing increased cyclic AMPCorrect answer
- EActivation of superantigen mediated cytokine release
- FActivation of guanylate cyclase increasing intracellular cGMP
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