Successful treatment of a penicillin-intermediate and ceftriaxone-resistant Granulicatella adiacens presumed prosthetic valve endocarditis with vancomycin.

Advancements in rapid diagnostics have helped to identify nutritionally variant streptococci (NVS) as an increasing cause of infective endocarditis (IE). This case report highlights the challenges in susceptibility testing and the importance of appropriate empiric treatment for Granulicatella adiacens, and provides considerations for future practice guideline recommendations. Guidelines for treatment of IE caused by NVS are currently limited to patients with native valve disease. We present a patient with presumed prosthetic valve endocarditis caused by G. adiacens, with clinically relevant resistance to recommended first-line agents (penicillin and ceftriaxone), who was successfully treated with 8 weeks of intravenous (IV) vancomycin. Vancomycin is currently recommended as an alternate therapy for patients intolerant of penicillins, but we believe vancomycin should be considered a first-line empiric treatment option for IE when the identified organism is G. adiacens and susceptibility testing is not readily available.