2026 Volume 68 Issue 3 Pages 219-227
Background and Objectives: In recent years, the evolutions of the pathogenesis of biliary tract infections and the antimicrobial susceptibility of the causative pathogens have gained considerable attention. Identifying the causative microorganisms and their susceptibility to antimicrobial agents is important in the treatment of biliary tract infections. The purpose of this study was to investigate changes in the causative bacteria of biliary tract infections and their antimicrobial susceptibility, as identifying these factors is crucial for effective treatment.
Methods: Bile samples were collected from patients with biliary tract infections during ERCP and cultured aerobically and anaerobically for bacteriological examination.
Results: Gram-negative rods, including Escherichia coli, were the most frequently detected aerobic bacteria, and no significant changes in the trends of bacterial species were evident. However, microbial susceptibility to ampicillin-sulbactam decreased overall. An increasing trend was observed in the number of patients with carbapenem-resistant Enterobacteriaceae and carbapenem-resistant Pseudomonas aeruginosa. Conversely, the detection rate of extended-spectrum β-lactamase-producing bacteria decreased.
Conclusion: Although there was no change in the type of bacteria found, changes in antimicrobial susceptibility from conventional patterns were observed. Therefore, collecting and culturing bile during ERCP is useful for selecting appropriate antibiotics for the treatment of biliary tract infections.
