Bacterial Infections USMLE Step 1 Practice Question
A 7 year old unimmunized girl is brought to the clinic with fever, sore throat, and neck swelling. Examination shows cervical lymphadenopathy and a thick gray pharyngeal pseudomembrane that bleeds when removed. She later develops palpitations and elevated troponin levels. Which of the following best describes the molecular action of the toxin responsible for this disease?
Answer choices
- AInactivation of elongation factor 2 by ADP ribosylationCorrect answer
- BCleavage of 28S ribosomal RNA
- CActivation of guanylate cyclase in intestinal epithelial cells
- DProteolytic activation of adenylate cyclase in host macrophages
- EInhibition of peptidoglycan cross linking
- FInactivation of 30S ribosomal subunit through direct binding to rRNA
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