USMLE Step 2 - Question 17

A 62 year old male with a history of mitral valve prolapse, rhematoid arhtritis, and colon cancer presents to the emergency room with increased dyspnea on exertion, lower extremity swelling, and fevers slowly worsning over the past month. His temperature is 38.0 C, blood pressure 95/65, heart rate 80, respirations 20, and oxygen saturation 92% on room air. Physical examination reveals normal breath sounds, a II/VI holosystolic murmur at the apex, and 1+ bilateral lower extremity pitting edema. Laboratory studies show a WBC count of 20 thousand and an ESR of 100. Echocardiogram reveals an 8 mm mobile vegitation on the anterior leaflet of the mitral valve. Which of the following is the most likely pathogen?

A. Staphalococcus aureus

B. Pseudomonas auriginosa

C. Candida albicans

D. Streptococcus bovis