Late bioprosthetic valve endocarditis caused by Phialemonium aff. curvatum and Streptococcus sanguis: a case report.

Dual fungal and Streptococcus sanguis endocarditis is reported in a 63-year-old woman 7 months after placement of a porcine aortic valve prosthesis. Both micro-organisms were isolated by blood cultures, and the patient succumbed after a full course of antibacterial chemotherapy without having received antifungal chemotherapy. The best possible designation of the fungus was Phialemonium aff. curvatum W. Gams & W. B. Cooke, as represented by CBS 331.93. At autopsy hyphae were revealed in the porcine valve tissue by conventional staining. A hyperimmune rabbit antiserum raised towards strain CBS 331.93 and extensively absorbed with heterologous fungal antigens reacted strongly with hyphae in the valve tissue by indirect immunofluorescence technique. We consider it most likely that the Phialemonium infection evolved insidiously from the time of open heart surgery and led to a haematogenous streptococcal infection of a more fulminant course.