Staphylococcus hyicus: A Novel Cause of Destructive Endocarditis Requiring Mitral Annular Reconstruction

Abstract

Infective endocarditis secondary to Staphylococcus hyicus (S. hyicus) infection has not previously been recorded. Clinically significant infections by S. hyicus have been documented three times prior to this report, where it has produced cellulitis, osteomyelitis, and profound septicaemia [ 1 Osterlund A, Nordlund E. Wound infection caused by Staphylococcus hyicus subspecies hyicus after a donkey bite. Scand J Infect Dis. 1997;29(1):95. Google Scholar , 2 Casanova C, Iselin L, von Steiger N, Droz S, Sendi P. Staphylococcus hyicus bacteremia in a farmer. J Clin Microbiol. 2011;49(12):4377–8. Google Scholar ]. This paper presents the first documented case of destructive endocarditis caused by S. hyicus in an immunocompetent man. This pathogen showed several unique and important features that differ from classic Staphylococcal infections. S. hyicus shows a strong zoonotic association and shares endotoxin-producing capabilities akin to that of Staphylococcus aureus. Its destructive and aggressive nature should not be overlooked when cultured; however, it is difficult to identify and advanced molecular identification may be required. The echocardiographic findings of this organism were as equally unusual and are detailed in the following report. In this case it produced necrosis of the mitral annulus, whilst sparing the mitral valve leaflets macroscopically and echocardiographically. Reconstruction of the mitral annulus and mitral valve replacement was required. Images including echocardiography, computed tomography, and intraoperative photos from this case are included for reference.