Staphylococcus hominis Infective Endocarditis Presenting with Embolic Splenic and Renal Infarcts and Spinal Discitis

Staphylococcus hominis (S. hominis) is a Gram-positive, coagulase-negative bacteria that occurs as a normal commensal organism on the skin and may rarely cause native valve endocarditis (NVE). We present a 62-year-old male with type 2 diabetes mellitus, coronary artery disease, and hypertension presenting with fever and abdominal pain. CT (computerized tomography) of the abdomen revealed splenic and renal infarcts; further imaging with MRI (magnetic resonance imaging) revealed enhancements consistent with discitis in T5-6 and L1-2. Three sets of blood cultures were positive for S. hominis sensitive to methicillin on antimicrobial susceptibility tests, and echocardiogram showed posterior mitral valve vegetation. The patient was initially treated with 10 weeks of nafcillin IV (intravenous) 2 g q4 hours. He had recurrent bouts of S. hominis bacteremia that was treated with IV vancomycin. His clinical course was complicated by new-onset atrial fibrillation with rapid ventricular response and congestive heart failure. Once bacteremia was cleared, his infective endocarditis was successfully definitively treated with mitral valve replacement and tricuspid repair.