A case of isolated tricuspid valve infective endocarditis caused by Abiotrophia defectiva.

A 17-year-old man with a history of dental caries was admitted to our hospital because of 1-week high fever. There was no history of previous cardiac disease. He denied drug abuse. Blood culture was positive for Abiotrophia defectiva. Echocardiography demonstrated large vegetation attached to the anterior cusp of the tricuspid valve with moderate regurgitation. Although he was treated with antibiotics for more than 3 weeks, he had chest pain due to septic pulmonary emboli on chest computed tomography. Surgical resection of the vegetation was performed. The postoperative course was uneventful and he is doing well at the time of follow-up.