Prosthetic valve endocarditis resulting from Nocardia asteroides.

Nocardia asteroides was isolated from the prosthetic valve of a 64-year-old woman who had died of endocarditis after aortic valve replacement. Multiple blood cultures had all been negative. This organism is increasingly being recognised as a pathogen and is usually sensitive to sulphonamides. These should be tried in culture negative endocarditis unresponsive to standard therapy.