ABSTRACT
A 66-year-old man was given a diagnosis of urinary-tract infection and hospitalized for 2 weeks in another hospital in late August 2009. In late October of that year he was transferred to our hospital by ambulance because he was unable to ingest anything orally. Echocardiography showed that a vegetation of about 10 mm in maximum dimension was attached to the aortic valve, causing severe aortic stenosis and regurgitation. The patient's general condition was poor, and sepsis and disseminated intravascular coagulation syndrome developed. The next day, an urgent operation was performed, and an abscess was observed occupying one-third of the aortic valve annulus. The abscess was completely excised and the abscess cavity was covered with an equine pericardium patch. We then performed aortic valve replacement using a bioprosthetic valve followed by tricuspid valve annuloplasty. <i>Peptostreptococcus </i>spp. was detected in a culture of the abscess. Infective endocarditis due to <i>Peptostreptococcus </i>spp. is rare. There has been no recurrence of infection for 7 months postoperatively.