Recurrent Staphylococcus warnerii prosthetic valve endocarditis: A case report and review

Coagulase-negative staphylococci (CoNS) have emerged in recent years as important nosocomial pathogens, with Staphylococcus epidermidis the most frequently recognized organism in this group [1]. S. warneri and other coagulase-negative staphylococci have been recognized less frequently as significant human pathogens [2].S. warnerii can cause catheter-related bacteremia, native and prosthetic valve endocarditis (PVE), hematogenous vertebral osteomyelitis and ventriculoperitoneal shunt-associated meningitis [3-10]. S. warnerii is a CoNS that has rarely been reported in infective endocarditis. To our knowledge, there have been only six S. warneri endocarditis cases reported in the English-language literature (Medline: 1966 to April 2011). We report a case of recurrent S. warneri endocarditis in a patient with prosthetic valve and silicon mammoplasty and we also review the relevant literature.A 43-year-old immunocompetent woman presented with a 20-day history of fever and night sweats. On the physical examination, she had an axillary temperature of 38.5°C, a heart rate of 90/min, a blood pressure of 90/70 mmHg and a diastolic murmur (2/4) at the aortic area. Routine chemistry panel and haemogram were normal. The C-reactive protein (CRP) level was 28 g/dl (normal <5) and had an erythrocyte sedimentation rate (ESR) of 30 mm/hour. Three years ago, she had an aortic valve replacement for congenital aortic stenosis. She had a silicon mammoplasty and dental extraction nine months and four months ago respectively prior to this presentation. Three months ago, she had been treated for S. warneri endocarditis with ceftriaxone and gentamicin for four weeks. After one month of being discharged from the cardiology department, the patient developed fever and night sweats again. On the second day of last hospitalization, painful nodules (Oslers nodes) were noted in the pad of the right index finger. We initiated empirical infective endocarditis treatment with ampicillin-sulbactam and g