Infective endocarditis due to Leptotrichia buccalis: a case report.

A patient with Down''s syndrome presented with infective endocarditis due to Leptotrichia buccalis. The source of the infection was not detected, but the predisposing factor was a complex cardiac malformation. The disease followed a subacute course, had a number of immunologic manifestations and was successfully treated with a 28-day course of penicillin G, given intravenously. L. buccalis has never been reported before as a cause of endocarditis.