155. A Case Series of Patients with Gemella Endocarditis

BACKGROUND: Gemella is a genus of gram-positive bacteria that thrives best at a high partial pressure of CO2 and is an unusual cause of infective endocarditis (IE). METHODS: We identified cases of Gemella IE in patients aged >18 years old, hospitalized at Cleveland Clinic between July 1, 2007 and January 1, 2017, by screening the Cleveland Clinic IE Registry. Gemella IE was defined as meeting modified Duke Criteria and having Gemella identified as the pathogen (by culture and/or 16S RNA sequencing from explanted valve tissue). Clinical features were obtained by manual chart review. RESULTS: A total of 13 cases of Gemella IE (G. haemolysans [6], G. morbillorum [3], G. sanguinis [2], and 2 undifferentiated species) were identified within the study period and accounted for <1% of all cases of IE. 9 were native valve IE and 4 were prosthetic valve endocarditis. Age varied from 20 to 86 years and 77% were male. The most common predisposing factors were pre-existing valvular disease (54%) and congenital heart disease (46%). 3 cases had dental manipulation within the prior 3 months, 3 had bioprosthetic valves, 2 had mechanical heart valves, and 2 were actively using intravenous recreational drugs. All cases were left-sided: 38% involved the aortic valve, 23% the mitral valve and 38% involved both. 69% had positive blood cultures, 38% had positive blood cultures and positive valve PCR, and 31% were identified based on positive valve PCR results only. Not one patient had positive valve cultures. 85% had significant valvular regurgitation and locally invasive disease occurred in 4 patients. Central nervous system emboli occurred in 3 cases and metastatic infection, in the form of lumbar diskitis, in one. All patients were treated surgically and the most commonly used anti-microbials were parenteral ceftriaxone and vancomycin, administered for a median duration of 42 days. All cases survived to hospital discharge and none relapsed over a median follow-up of 2.2 years. CONCLUSION: Gemella species account for less than 1% of cases of IE, with G. haemolysans being the most common species. In a third of cases valve PCR provided the only means of diagnosis. It is effectively treated with surgery and antibiotics. DISCLOSURES: All authors: No reported disclosures.