Propionibacterium acnes as a cause of aggressive aortic valve endocarditis and importance of tissue grinding: case report and review.

A case of prosthetic valve endocarditis with Propionibacterium acnes is described. The diagnosis was documented by histology and isolation of P. acnes from both blood and anulus tissue. Grinding of the tissue, which was first omitted to avoid contamination, was indispensable for cultivating the agent. The literature for P. acnes endocarditis is reviewed.