RESUMEN
A 35-year-old man with pre-existing rheumatic heart disease and aortic regurgitation [AR] presented with intermittent fever, ankle swelling and clinical evidence of endocarditis. Transoesophageal echocardiogram [TEE] revealed vegetations and destruction of the aortic valve [AV]. Blood cultures grew a gram positive coccobacillus which was phenotypically identified as Abiotrophia defectvia [A.defectiva]. A diagnosis of infective endocarditis [IE] due to A.defectiva was made. Treatment, with penicillin and gentamicin, was administered for 4 weeks. Mechanical valve replacement was required few days after starting the antibiotic therapy. The patient had a favorable outcome on follow up. Although A.defectiva is an uncommon cause of endocarditis, early and correct identification of this pathogen is important to improve the outcome and the prognosis of patients with IE due to this organism