A 52-year-old active smoker comes to the office due to a 2-week history of malaise, shortness of breath, and decreased appetite. The patient has a history of bicuspid aortic valve and hypertension. His temperature is 39 C (102.2 F), blood pressure is 140/80 mm Hg, and pulse is 110/min. On examination, the patient has a systolic ejection murmur at the right upper sternal border that is unchanged from previous visits; there is a new decrescendo diastolic murmur best heard in the third intercostal space at the left sternal border. Laboratory studies show hemoglobin is 9.3 g/dL and leukocytes are 16,500/mm³. Blood cultures are positive for Streptococcus gallolyticus (formerly S bovis). Additional workup for this patient should focus on which of the following conditions?

Question

Quizplus · Accepted Answer

Streptococcus gallolyticus (formerly S bovis) is the main human pathogen among nonenterococcal group D streptococci. It causes a subacute bacterial endocarditis (SBE) with symptoms similar to those of S viridans SBE. S gallolyticus is part of the normal flora of the colon, and bacteremia or endocarditis caused by S gallolyticus is associated with colonic cancer in ~25% of cases. The relationship between S gallolyticus and colon cancer is unclear, but every patient with S gallolyticus bacteremia with or without endocarditis should be examined for a gastrointestinal tract malignancy. S gallolyticus endocarditis is also unique in that most cases occur in patients without preexisting valvular abnormality. (Choice B) Right-sided endocarditis commonly occurs in intravenous drug users and is typically caused by Staphylococcus aureus. (Choices C and E) There is no known association between endocarditis and lung cancer. S gallolyticus can cause septic shock, meningitis, or joint infection; it does not typically cause urinary tract infections. (Choice D) S viridans is the most common etiologic agent in subacute bacterial endocarditis following dental work. Educational objective: Streptococcus gallolyticus (formerly S bovis) endocarditis and bacteremia are associated with gastrointestinal lesions (colon cancer) in ~25% of cases. When S gallolyticus is cultured in the blood, workup for colonic malignancy with colonoscopy is essential.

A 52-Year-Old Active Smoker Comes to the Office Due to a 2-Week