Quadruple-valve infective endocarditis caused by Abiotrophia defectiva.

Quadruple-valve endocarditis is a challenging condition, for which there is limited treatment experience and poor overall survival. We report the first case caused by Abiotrophia defectiva that has been surgically treated both with the replacement of the aortic and pulmonary valves and the repair of the mitral and tricuspid valves with a good outcome. The patient's clinical course is described and a review of literature on this rare causative agent is given.