Bacterial Infections USMLE Step 1 Practice Question
A 34 year old man who works processing imported animal hides presents with fever, dyspnea, and chest discomfort. Chest radiograph shows a widened mediastinum and pleural effusions. Blood cultures grow large gram positive spore forming rods. Which of the following virulence mechanisms is most directly responsible for the marked edema seen with this infection?
Answer choices
- AInactivation of elongation factor 2
- BInhibition of acetylcholine release at the neuromuscular junction
- CCleavage of synaptobrevin in inhibitory neurons
- DSuperantigen mediated T cell activation
- EAdenylate cyclase mediated increase in cyclic AMPCorrect answer
- FInhibition of phagocytosis through polysaccharide capsule synthesis
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.