Bacterial Infections USMLE Step 1 Practice Question
A 24 year old woman with cystic fibrosis is admitted for worsening cough, fever, and increased sputum production. Sputum culture grows an oxidase positive gram negative rod that produces blue green pigment and has a fruity odor. Which of the following virulence mechanisms is most closely associated with severe tissue necrosis caused by this organism?
Answer choices
- APreformed heat stable toxin activation of guanylate cyclase
- BSuperantigen activation of T lymphocytes
- CCleavage of 28S ribosomal RNA
- DADP ribosylation of elongation factor 2Correct answer
- EInactivation of Rho GTPases
- FPhospholipase C mediated degradation of phosphatidylinositol 4,5-bisphosphate
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