Pneumonia USMLE Step 1 Practice Question
A 45-year-old woman recovering from influenza develops recurrent fever (39.2°C), progressive dyspnea, and productive cough with purulent sputum. Vital signs show BP 128/82 mmHg, HR 112/min, RR 22/min, SpO2 94% on room air. Chest CT reveals multiple patchy infiltrates with cavitary lesions in the right upper lobe. WBC count is 14,200/μL. She denies recent antibiotic use. Which organism is most likely responsible?
Answer choices
- AStreptococcus pneumoniae
- BStaphylococcus aureus pneumoniaCorrect answer
- CChlamydophila psittaci
- DMycoplasma pneumoniae
- EPneumocystis jirovecii pneumonia
- FKlebsiella pneumoniae
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.