Bacteriology USMLE Step 1 Practice Question
A 24-year-old female presents with fever (38.9°C), malaise, and a dry, nonproductive cough for 5 days. She reports headache, myalgias, and leg pain. Vital signs show HR 102/min, RR 18/min, BP 118/76 mmHg, SpO2 98% on room air. Laboratory studies reveal elevated cold agglutinins (titer 1:512) and mild anemia. Chest X-ray shows interstitial infiltrates. She denies recent antibiotic use. Which microorganism is responsible for her symptoms?
Answer choices
- AKlebsiella pneumoniae
- BLegionella pneumophila
- CMycoplasma pneumoniaeCorrect answer
- DHaemophilus influenzae
- EStreptococcus pneumoniae
- FChlamydophila pneumoniae
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