<prompt> A 62-year-old man with a prosthetic aortic valve develops fevers and malaise. His valve was replaced 5 years ago because of aortic stenosis from a bicuspid valve. He has a systolic ejection murmur but no other abnormalities on examination. Blood cultures are most likely to grow which of the following?fungibartonelladiphtheroidStaphylococcus epidermidis  <response>: S. epidermidis is still the most frequent early and late cause of endocarditis in patients with prosthetic heart valves. The other organisms are seen less frequently in late prosthetic valve endocarditis. 