923Lactococcus garvieae infective endocarditis requiring valve replacement: First case in the United States

Background. Lactococcus, a gram-positive organism of low virulence, is an uncommon cause of human infection. Infective endocarditis due to Lactococcus is extremely rare. Methods. We present a case of native aortic valve endocarditis due to Lactococcus garvieae with severe aortic insufficiency requiring valve replacement. Results. The patient is a sixty year old male with history of Waldenstrom’s macroglobulinemia for which he had been receiving intravenous immunoglobulin infusions for the previous two years. He was admitted to the hospital with a two week history of fatigue, decreased appetite and worsening shortness of breath. Chest radiograph showed findings consistent with interstitial pulmonary edema. Blood cultures grew Lactococcus garvieae. A transesophageal echocardiogram showed a mobile echodensity on the aortic valve extending into the left ventricular outflow tract; there was associated leaflet perforation and severe aortic regurgitation. Two thirds of the aortic valve leaflets were essentially destroyed. The patient underwent aortic valve replacement with a pericardial valve. Surveillance blood cultures and cultures of the resected valve were negative. He was treated with vancomycin and gentamicin for two weeks, followed by ceftriaxone for a total of six weeks. The patient has done well since discharge from the hospital, with a follow up transthoracic echocardiogram showing a normally functioning bioprosthetic aortic valve. Lactococcus. was placed in a separate genus from Streptococcus in 1985 based on genetic analysis. L. garvieae is a catalase-negative, facultatively anaerobic, serogroup N, gram-positive coccus. A review of the English literature revealed fifteen cases of infective endocarditis due to L. garvieae. More than half of the patients had a prosthetic or repaired valve. Most patients were treated medically with the majority receiving a six week course of β-lactams. All but one patients survived. Conclusion. Lactococcus garvieae is an extremely uncommon cause of infective endocarditis. β-lactams appear to be the antibiotics of choice, and the prognosis is favorable. We believe our patient represents the first case in the US that required valve replacement. Disclosures. All authors: No reported disclosures.