Risk Factors for Multi-Drug Resistant Pathogens and Failure of Empiric First-Line Therapy in Acute Cholangitis

Background Acute cholangitis (AC) requires the immediate initiation of antibiotic therapy in addition to treatment for biliary obstruction. Against a background of an increasing prevalence of multi drug resistant (MDR) bacteria, the risk factors for the failure of empiric therapy must be defined. Methods Using a pathogen-based approach, 1764 isolates from positive bile duct cultures were retrospectively analyzed to characterize the respective pathogen spectra in two German tertiary centers. Using a patient-based approach, the clinical and laboratory data for 83 patients with AC were assessed to identify risk factors for AC with pathogens resistant to the applied empiric therapy. Results Bile cultures were predominantly polymicrobial, and empiric antibiotic therapies did not cover the full biliary pathogen spectrum in 78% of cases. MDR bacteria were isolated from the bile of 24/83 (29%) patients. The univariate risk factors for biliary MDR bacteria were male sex, nosocomial AC, prior antibiotic exposure and prior biliary stenting, of which biliary stenting was the only independent risk factor according to multivariate analysis (OR = 3.8; 95% CI 1.3-11.0, P=0.013). Although there were no significant differences in survival or hospital stay in AC patients with and without detected biliary MDR pathogens, the former more often had a concomitant bloodstream infection (58% vs. 24%; P= 0.019), including those involving MDR pathogens or fungi (21% vs. 2%; P= 0.007). Conclusion Patients with biliary stents who develop AC should receive empiric therapy covering enterococci and extended-spectrum beta-lactamase(ESBL)-producing Enterobacteriaceae. These patients are at an increased risk for bloodstream infections by MDR pathogens or fungi.