Endocarditis caused by Moraxella nonliquefaciens.

We have described a case of endocarditis caused by Moraxella nonliquefaciens on a prosthetic Hancock valve, which was cured with a six-week course of ampicillin and gentamicin therapy. Cases of Moraxella septicemia or endocarditis are uncommon, and this apparently represents the first case of Moraxella nonliquefaciens endocarditis on a prosthetic valve. The fastidious growth characteristics of this and similar species may require prolonged incubation of blood cultures and development of different methods for testing the bactericidal activity of the patient's serum.