Lactobacillus Endocarditis: A Chronic Active Infection

Lactobacilli are gram positive rod-shaped or filamentous bacteria that are a rare cause of endocarditis. We review the literature of less than 50 reported cases, and present a case of a 43-year-old male with a protracted, one-year history consistent with endocarditus. The pathologic findings in the heart at autopsy indicate a long, chronic course of smoldering infection with extensive secondary fibroelastosis of valvular structure and adjacent endocardium, although superimposed more acute vegetation with viable organisms consistent with the premortem blood culture of Lactobacillus acidophilus were abuntly present. Thus, the pathologic and clinical features of this case, and our review of the available literature, suggest that infective endocarditis caused by Lactobacillus species has an indolent nature and results in severe, chronic alterations of valvular structure.