Perinephric Abscess and Bacteremia Due to Lactobacillus Species in a Diabetic Adult

Lactobacillus species are a group of anaerobic or facultatively anaerobic, catalase-negative, gram-positive non–spore-forming rods that are usually considered benign commensal organisms present in the human mouth and gastrointestinal and genital tracts. Given their indolent nature, the presence of Lactobacillus species in cultures is often considered contaminants. In rare occasions, however, Lactobacillus species have been reported as pathogens causing a broad range of clinically significant conditions including bacteremia, endocarditis, dental abscesses, meningitis, and intra-abdominal infections such as peritonitis, endometritis, and splenic and liver abscesses. Pyelonephritis has only been seldomly reported in literature, and perinephric abscess has never been reported in literature to date. When infection happens, it usually occurs in immunosuppressed individuals such as those with cancer, transplant recipients, chronic steroid use, or human immunodeficiency virus/AIDS. Despite being gram-positive, the bacteria are usually resistant to vancomycin, and treatment with a penicillin-based regimen is preferred. We describe a case of a diabetic and morbidly obese, but otherwise healthy man, who developed bacteremia and perinephric abscess due to Lactobacillus species.