Corynebacterium jeikeium native valve infective endocarditis case report: a confirmed microbiological and pathological diagnosis from heart valvular tissue

Abstract

Abstract Background The Modified Duke criteria is an important structured schematic for the diagnosis of infective endocarditis (IE). Corynebacterium jeikeium is a rare cause of IE that is often resistant to standard IE anti-microbials. We present a case of C. jeikeium IE, fulfilling the Modified Duke pathological criteria. Case summary A 50-year-old male presented with left leg peripheral vascular disease with septic changes requiring amputation. Routine echocardiography post-amputation demonstrated severe aortic valve regurgitation with vegetations that required valve replacement. Two initial blood cultures from a single venepuncture showed Streptococcus mitis which was treated with penicillin G prior to surgery. Subsequent aortic valve tissue cultured C. jeikeium with suggestive IE histological valvular changes and was successfully treated on a prolonged course of vancomycin. Discussion This is the first C. jeikeium IE case diagnosed on heart valvular tissue culture and highlights the importance for the fulfilment of the Modified Duke criteria in diagnosing left-sided IE. Mixed infection IE is rare, and this case possibly represents an unmasking of resistant C. jeikeium IE following initial treatment of penicillin G.