Bacteriology USMLE Step 1 Practice Question
A 45-year-old man with COPD presents with sudden-onset fever (39.2°C), productive cough with blood-tinged sputum, and pleuritic chest pain. Vital signs show HR 108/min, RR 22/min, BP 128/82 mmHg, and SpO2 94% on room air. Sputum culture grows gram-positive diplococci that are optochin-sensitive and bile-soluble. Chest X-ray demonstrates left lower lobe consolidation. He denies recent antibiotic use. Which of the following is most appropriate initial therapy?
Answer choices
- AFluoroquinolone monotherapy
- BMacrolide monotherapy
- CPenicillin G or high-dose amoxicillinCorrect answer
- DMetronidazole plus ceftriaxone
- EVancomycin alone
- FCephalexin monotherapy
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.