Silent Native-valve Endocarditis Caused by Propionibacterium acnes

We describe a rare case of Propionibacterium acnes native-valve endocarditis that silently progressed in a 67-year-old man with hybrid dialysis. The patient was scheduled for kidney transplantation, and pre-operative investigation incidentally detected a vegetative structure at his native mitral valve that had increased in size. He underwent cardiac surgery and P. acnes was detected in cultures of a resected cardiac valve specimen and blood. This case highlights that P. acnes can silently cause infective endocarditis in a native-valve, and that physicians should consider the possibility of infection when P. acnes is isolated in blood cultures.