Native mitral valve infective endocarditis due to Dolosigranulum pigrum

Dolosigranulum pigrum is an anaerobic, gram-positive coccus rarely identified as a pathogenic organism. However, case reports have suggested D. pigrum as a causative pathogen in bacteremia, nosocomial pneumonia, ventilator-associated pneumonia, synovitis, cholecystitis, and ophthalmologic infections. Herein, we present the first case of Dolosigranulum pigrum causing native mitral valve infective endocarditis. With the exception of erythromycin, the isolate displayed favorable minimum inhibitory concentrations (MIC) to all other antibiotics tested, including beta-lactams, levofloxacin, and vancomycin. The patient was successfully treated with a 6-week course of intravenous (IV) ceftriaxone followed by robotically assisted cardiac valve repair.