An Unusual Case of Acute Cholecystitis Caused by Lactobacillus paracasei.

Lactobacillus paracasei is a gram-positive rod commonly found in probiotic foods and is well known to promote healthy gastrointestinal tracts. However, there have been a few case reports that have found Lactobacillus paracasei to be the causative agent in complications such as endocarditis, meningitis, peritonitis, pancreatitis, and cholecystitis. We present the case of a 76-year-old woman who was admitted for decompensated heart failure. The patient also reported abdominal pain in the right upper quadrant. Ultrasound findings suggested cholelithiasis and a subsequent hepatobiliary iminodiacetic acid (HIDA) scan confirmed acute cholecystitis. This patient was not a good candidate for cholecystectomy because of the risk of cardiac complications. Hence, percutaneous cholecystostomy tube (PCT) placement was done, and the aspirate drained during the procedure was sent for pathology. This bile culture was positive for Lactobacillus paracasei and negative for any other kinds of bacteria. The incidence of Lactobacillus species-induced cholecystitis makes up only 0.08% to 0.2% of cases, which makes this an unusual case of acute cholecystitis caused by Lactobacillus paracasei. We will discuss several pathogenic aspects of Lactobacillus paracasei, such as its ability to generate biofilms, pore-forming toxins, drug transporters, and antibiotic susceptibility.