Endocarditis caused by Neisseria elongata subspecies nitroreducens: case report and literature review.

Neisseria elongata subsp. nitroreducens, an usual commensal of the nasopharynx, can cause serious infections, usually endocarditis. A case of Neisseria elongata endocarditis complicating mitral valve prolapse in a patient allergic to penicillin is reported. Cure was obtained with a combination of ceftriaxone and gentamicin, there being no requirement for surgery during the acute phase of the disease.