A Double Whammy: Lactobacillus acidophilus Bacteremia and Subsequent Lactobacillus rhamnosus Prosthetic Valve Infective Endocarditis in an Elderly Diabetic Patient.

The clinical significance of the relatively avirulent organ- ism, Lactobacillus, has been debated in the past. At times misdiagnosed as a contaminant, Lactobacillus has uncommonly been reported to cause intra-abdominal abscesses, peritonitis, meningitis, bacteremia, pneumonia and endocarditis, especially in the population of patients with underlying comorbid conditions including malignancy, diabetes, recent surgery or organ transplantation. We report a case of a 74-year-old male with Lactobacillus bacteremia leading to prosthetic valve infective endocarditis complicated by an aortic root abscess. He was managed with IV antibiotic therapy, ultimately penicillin G, and aortic valve replacement, and completely recovered after a period of rehabilitation. Several factors that predispose to Lactobacillus bacteremia were identified in our patient. This case further supports the proposition that Lactobacillus is not always a contaminant; when pathogenic, underlying disease conditions should be investigated.