Bacterial Infections USMLE Step 1 Practice Question
A 73 year old man presents with 2 weeks of low grade fever and malaise. One month ago he underwent transurethral resection of the prostate for urinary obstruction. Cardiac examination reveals a new blowing systolic murmur, and blood cultures grow gram positive cocci that are catalase negative, gamma hemolytic, and able to grow in bile and 6.5 percent sodium chloride. Which of the following is the most likely causal organism?
Answer choices
- AEscherichia coli
- BStreptococcus pyogenes
- CEnterococcus faecalisCorrect answer
- DStreptococcus gallolyticus
- EStaphylococcus epidermidis
- FStreptococcus agalactiae
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.