Aortic endocarditis caused by gentamicin-resistant Enterococcus faecalis.

A case is reported of a patient who developed aortic endocarditis after protracted hospitalization during which time the patient received multiple courses of aminoglycoside and cephalosporin therapy. The infecting organism, an Enterococcus faecalis strain, was resistant to gentamicin and to the combination of ampicillin with gentamicin. Valve replacement was performed after four weeks of therapy with ampicillin, and enterococci were isolated from cardiac vegetations. Valve replacement may be necessary to achieve cure of endocarditis due to enterococci highly resistant to gentamicin.