Cholelithiasis - always infected?

Abstract

This study aims to present results regarding the presence and identification of bacterial strains found in bile and gallstones located in the gallbladder and bile ducts in patients operated on due to cholelithiasis.

Materials and methods: Bacterial culture was evaluated in 92 patients. There were 54 women (59%) and 38 men (41%) who underwent surgery on account of cholelithiasis and /or gallstones in bile ducts between 2013 and 2014. Bile and gallstone samples were cultured intraoperatively for bacteria; bacterial strains were identified, and their sensitivity to antibiotics was determined. Molecular methods (NGS and Sanger method) were used to separate bacterial strains in one of the gallbladder stones and the results were compared with bacterial strains grown from the bile.

Results: Bile cultures were positive in 46 patients that is, 50% of the study group. The following bacteria strains were grown: Enterococcus spp. (44%), Escherichia coli (37%) and Klebsiella spp. (35%). Candidiasis accompanied by bacterial infection was detected in 7 patients (15%). Molecular testing of gallstones revealed DNA of Enterococcus spp., Escherichia spp., Streptococcus spp. and Clostridium spp. In the bile culture of the same patient Enterococcus spp. (avium and faecalis) was detected. Conclusion 1. More than one pathogen was grown on samples obtained from 31 patients (70%) with bile infection. 2. The most common pathogens include Enterococcus spp., Escherichia coli and Klebsiella spp. 3. Bacterial infections are often accompanied by a fungal infection (Candida albicans) 4. Bacterial strains grown from a gallstone sample partially corresponded with strains identified in the bile of the same patient.

Keywords: bacteria; bile; bile deposits; biliary infection; gallstones.