Prevalence, Resistance Rates, and Risk Factors of Pathogens in Routine Bile Cultures Obtained during Endoscopic Retrograde Cholangiography

Abstract

Introduction and Objective Acute cholangitis is a life-threatening condition. The early initiation of antibiotic therapy significantly impacts on the course of disease. Only few data are available on distribution and resistance-profiles of bile-pathogens. Here we report on an analysis of routinely acquired bile-specimens and provide an overview of the prevalence, resistance-rates and risk-factors for the presence of pathogens in bile. Methods Bile-cultures obtained from 388 endoscopic retrograde cholangiographies (ERC) with corresponding clinical data were analysed in 208 patients. Results The majority (84.8%) of cultures yielded positive for at least one organism. Abundancy was highest for Enterococcus faecalis, Enterococcus faecium and Escherichia coli. Multiresistant organisms were present in 14.9%. The initial antibiotic regimen was changed in 44.1 %, which increased the length of hospital-stay significantly (*** p<0.001). Pre-existing papillotomy (EPT) or biliary drainage were associated with higher frequency of bile-pathogens (** p<0.01) in an univariate-analysis. Multivariate-analysis confirmed these results for EPT, and revealed significantly more positive results for pathogens, Gram-negative bacteria and fungi in patients with biliary drainage. Significant differences in the prevalence of pathogens were observed between relevant subgroups of ERC-indications. The highest susceptibility-rates were observed for Linezolid and Tigecyclin in Gram-positive and for Meropenem and Gentamicin in Gram-negative bacteria. Conclusions Our study provides a comprehensive analysis of the distribution, resistance-profiles and risk-factors for the detection of bile-pathogens. The frequent change in initial antibiotic treatment highlights the importance of routine bile-culture and indicate that current schemas of empiric treatment might not cover the contemporary spectrum of pathogens in bile.