Pneumonia USMLE Step 1 Practice Question
A 40-year-old woman with a history of splenectomy presents with fever, productive cough, and dyspnea. Vital signs show temperature 39.2°C, heart rate 102/min, respiratory rate 22/min, blood pressure 128/82 mmHg, and SpO2 94% on room air. Chest X-ray demonstrates right middle lobe consolidation. Blood culture grows gram-positive, lancet-shaped diplococci. She denies recent antibiotic use. Which organism is most likely responsible for her infection?
Answer choices
- AKlebsiella pneumoniae
- BLegionella pneumophila
- CStaphylococcus aureus pneumonia
- DStreptococcus pneumoniaeCorrect answer
- EMycoplasma pneumoniae
- FHaemophilus influenzae
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