[Infectious Endocarditis due to Methicillin-sensitive Bovine Staphylococcus aureus;Report of a Case].

A 19-year-old male patient was admitted to our hospital after developing infectious endocarditis associated with methicillin-sensitive bovine Staphylococcus aureus septicemia. Brain magnetic resonance imaging confirmed occipital lobe cerebral bleeding. An echocardiogram showed severe mitral regurgitation with vegetation on the posterior mitral leaflet. We performed mitral valve replacement. However, a hepatic artery aneurysm and a ruptured splenic artery aneurysm was found on the 5th postoperative day and coil embolization was accordingly performed. The patient suffered repeated cerebral bleeding and received external decompression. He was discharged on the 92nd day after the valve replacement. Our case is rare in that methicillin-sensitive bovine Staphylococcus aureus isolated from human is extremely unusual especially complicated by multiple peripheral aneurysms. This is the 1st reported case of methicillin-sensitive bovine Staphylococcus aureus isolated from human in the Japanese literature.