A 28-year-old man is brought to the emergency department because of a 3-day history of fever, chills, and generalized weakness. He has no cough. He underwent routine dental cleaning with no complications. The patient has a history of mitral valve prolapse. He takes no medications. He has smoked one pack of cigarettes daily for 10 years and drinks two to three beers daily. He appears ill. His temperature is 38.6°C (101.5°F), pulse is 112/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. There are retinal hemorrhages with pale centers. The lungs are clear to auscultation. A grade 3/6 holosystolic murmur is heard best at the lower left sternal border. Blood cultures are drawn and grow gram-positive bacteria that synthesize dextrans from sucrose. Which of the following would be the most likely adherence site for these bacteria?

Question

A 28-year-old man is brought to the emergency department because of a 3-day history of fever, chills, and generalized weakness. He has no cough. He underwent routine dental cleaning with no complications. The patient has a history of mitral valve prolapse. He takes no medications. He has smoked one pack of cigarettes daily for 10 years and drinks two to three beers daily. He appears ill. His temperature is 38.6°C (101.5°F), pulse is 112/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. There are retinal hemorrhages with pale centers. The lungs are clear to auscultation. A grade 3/6 holosystolic murmur is heard best at the lower left sternal border. Blood cultures are drawn and grow gram-positive bacteria that synthesize dextrans from sucrose.  Which of the following would be the most likely adherence site for these bacteria?

Quizplus · Accepted Answer

Eductional Objective: Viridans streptococci are normal inhabitants of the oral cavity and are a cause of transient bacteremia after dental procedures in healthy and diseased individuals.  In patients with pre-existing valvular lesions, viridans streptococci can adhere to fibrin-platelet aggregates and establish infection that leads to endocarditis.

A 28-Year-Old Man Is Brought to the Emergency Department Because