Kocuria kristinae endocarditis related to diabetic foot infection

We report an unusual case of endocarditis occurring in a 74-year-old man with a history of systemic hypertension, diabetes mellitus and minor amputation for left forefoot ulcer. The patient was hospitalized for vacuum-assisted closure therapy to aid in wound healing. After the first treatment session, the patient reported abdominal pain with haematemesis and fever (40 degrees C). Owing to persistent fever, three blood cultures were performed, all positive for Kocuria kristinae. The identification was based on biochemical tests and automated systems. The speciation of the micro-organism was achieved with MALDI-TOF and then confirmed by 16S rRNA gene sequencing. Transthoracic echocardiographic examination showed the presence of a large vegetation (38x20 mm) on the posterior mitrel leaflet and moderate mitral regurgitation. Since there are no current guidelines for the treatment of K. kristinae endocarditis, empiric antibiotic therapy with intravenous sulbactam/ampicillin (1.5 g twice daily) and gentamicin (6 mg kg(-1) per day) was started. After 7 days of hospitalization, the patient's condition suddenly worsened because of the occurrence of haemorrhagic stroke. Despite inotropic support and rifampicin infusion, the haemodynamic status progressively deteriorated. After an initial improvement, he worsened again, becoming stuporous, hypotensive and dyspnoeic. In the following days, the patient developed compartment syndrome resulting in right foot ischaemia. Unfortunately, 25 days after hospitalization, the patient died of multiple organ failure from overwhelming sepsis. To the best of our knowledge, this is the first case of K. kristinae endocarditis on a native valve that is not related to a central venous catheter but associated with diabetic foot infection.