Bacterial remnants in an aortic valve after treatment for staphylococcal endocarditis

A patient with staphylococcal endocarditis was treated for 6 weeks with high doses of nafcillin. Despite a prompt clinical response and bacteriologic cure, residual damage to the aortic valve led to severe congestive heart failure necessitating surgery. Valve tissue obtained at surgery was sterile, but organisms consistent with staphylococci were observed in the inflammatory infiltrate by light and electron microscopy.