Recurrent Lactobacillus Bacteremia in a Patient With Leukemia

Lactobacillus species are a commensal flora of the human gastrointestinal and the female genitourinary tract. Lactobacilli especially the rhamnosus species, are common components of commercial probiotics. They are rarely associated with pathology in immunocompetent people, but they have been known to cause dental caries, bacteremia, and endocarditis in patients with suppressed immune function. Cases of Lactobacillus bacteremia have been reported in patients with acute myeloid leukemia, large granular lymphocytic leukemia, and in transplant recipients. In this article, we report a strange case of recurrent Lactobacillus bacteremia causing multiple episodes of fever of unknown origin in a patient with leukemia. This report is unique as Lactobacillus is not recognized as a common source of bacteremia. Moreover, the source of the bacillus continued to elude us even after extensive investigation.