Immunology USMLE Step 1 Practice Question
A 4 month old infant with no prior vaccinations is brought to clinic because of paroxysmal coughing spells followed by inspiratory whooping and posttussive vomiting. The responsible organism produces a toxin that increases cyclic AMP by preventing inhibition of adenylate cyclase. This toxin acts by which of the following mechanisms?
Answer choices
- AADP ribosylation of Gs
- BCleavage of SNARE proteins
- CInactivation of elongation factor 2
- DActivation of guanylate cyclase
- EADP ribosylation of GiCorrect answer
- FBlockade of phosphodiesterase activity
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