Pneumonia USMLE Step 1 Practice Question
A 63-year-old man presents with a 3-day history of high fever, confusion, watery diarrhea, and nonproductive cough following attendance at a hotel conference. Vital signs show temperature 39.2°C, BP 128/76 mmHg, HR 102/min, RR 22/min, and SpO2 94% on room air. Laboratory studies reveal hyponatremia (126 mEq/L) and elevated LDH. Chest X-ray shows patchy left lower lobe consolidation. He denies taking antibiotics prior to presentation. Which organism is most likely responsible?
Answer choices
- AMycoplasma pneumoniae
- BKlebsiella pneumoniae
- CStreptococcus pneumoniae
- DChlamydophila psittaci
- ELegionella pneumophilaCorrect answer
- FCoxiella burnetii
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