Bacteriology USMLE Step 1 Practice Question
A 60-year-old female comes to the physician because of fever, chills, and a cough for the past 2 weeks. She lives at home with her husband, has no chronic medical conditions, and has not traveled recently. She does not smoke cigarettes or drink alcohol. Her temperature is 38.2°C (100.8°F). Physical examination reveals altered breath sounds. Chest x-ray is abnormal. Which of the following is the most likely causal organism?
Answer choices
- AHaemophilus influenzae
- BStreptococcus pneumoniaeCorrect answer
- CMycoplasma pneumoniae
- DStaphylococcus aureus
- EChlamydophila pneumoniae
- FLegionella pneumophila
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.