An unusual etiology of infective endocarditis: Enterobacter cloacae.

Gram-negative microorganisms are rarely implicated in causing infective endocarditis (IE). Although the traditionally identified risk factor for Gram-negative endocarditis has been intravenous drug abuse, recent studies have revealed that healthcare contact and the presence of prosthetic cardiac devices are primary risk factors for IE secondary to non-HACEK Gram-negative bacteria. We present a case of Enterobacter endocarditis in a patient with no prior history of valvular heart disease, implanted endovascular device, or intravenous drug abuse. The patient was treated successfully with carbapenem monotherapy. We have reviewed 43 cases of Enterobacter endocarditis reported in the literature to date. Clinical summary and management of IE secondary to Enterobacter based on all the published cases is outlined.