Endocarditis due to Peptostreptococcus anaerobius: case report and literature review of peptostreptococcal endocarditis.

Infective endocarditis caused by anaerobic streptococci occurs rarely, and only five cases have been described in detail, with two additional cases mentioned in a review of anaerobic infective arthritis. All have resulted from infection caused by peptostreptococci. Another case of anaerobic gram-positive endocarditis caused by Peptostreptococcus anaerobius has recently been encountered. The patient was successfully treated with a beta-lactam for six weeks, plus gentamicin (to which the organism was resistant in vitro) for two weeks. In reviewing these six cases, all but one involved a prosthetic valve, and in three instances the organism was isolated only from the infected valve. In four of six patients the aortic valve was involved, and five of the six survived with appropriate antimicrobial therapy. Embolic phenomena were confirmed in only one patient, who also manifested the only non-diagnostic echocardiogram.