Endocarditis caused by Neisseria mucosa in a patient with a prosthetic heart valve

A forty year old man was admitted with suspected subacute bacterial endocarditis. Neisseria mucosa was isolated in pure culture. Initial antibiotic therapy included penicillin and gentamicin. After onset of allergic symptoms, penicillin was discontinued and vancomycin therapy instituted. Gentamicin therapy was discontinued after the serum creatinine began to rise. Minimum inhibitory concentration indicated that N mucosa was resistant to vancomycin. After allergy testing proved negative, intravenous penicillin therapy was reinstituted and continued until discharge, at which time the patient was to continue on oral penicillin for six months.