Background/Aims: Acute cholangitis (AC) is a potentially life-threatening bacterial infection, and timely antimicrobial treatment, faster than that achieved with bacterial cultures, is recommended.Although the current guidelines refer to empirical antimicrobial treatment, various kinds of antimicrobial agents have been cited because of insufficient analyses on the spectrum of pathogens in AC. Enterococcus spp. is one of the most frequently isolated Gram-positive bacteria from the bile of patients with AC, but its risk factors have not been extensively studied. This study aimed to analyze the risk factors of AC caused by Enterococcus faecalis and Enterococcus faecium. Methods: Patients with AC who were hospitalized in a Japanese tertiary center between 2010 and 2015 were retrospectively analyzed. Patients’ first AC episodes in the hospital were evaluated. Results: A total of 266 patients with AC were identified. E. faecalis and/or E. faecium was isolated in 56 (21%) episodes of AC. Prior endoscopic sphincterotomy (EST), the presence of a biliary stent, prior cholecystectomy, and past intensive care unit admission were more frequently observed in AC patients with E. faecalis and/orE. faecium than in those without such bacteria. Prior EST was identified as an independent risk factor for AC caused by E. faecalis and/or E. faecium in the multivariate analysis. Conclusions Given the intrinsic resistance of E. faecalis and E. faecium to antibiotics, clinicians should consider empirical therapy with anti-enterococcal antibiotics for patients with prior EST.

Background/Aims: Acute cholangitis (AC) is a potentially life-threatening bacterial infection, and timely antimicrobial treatment, faster than that achieved with bacterial cultures, is recommended.Although the current guidelines refer to empirical antimicrobial treatment, various kinds of antimicrobial agents have been cited because of insufficient analyses on the spectrum of pathogens in AC. Enterococcus spp. is one of the most frequently isolated Gram-positive bacteria from the bile of patients with AC, but its risk factors have not been extensively studied. This study aimed to analyze the risk factors of AC caused by Enterococcus faecalis and Enterococcus faecium. Methods: Patients with AC who were hospitalized in a Japanese tertiary center between 2010 and 2015 were retrospectively analyzed. Patients’ first AC episodes in the hospital were evaluated. Results: A total of 266 patients with AC were identified. E. faecalis and/or E. faecium was isolated in 56 (21%) episodes of AC. Prior endoscopic sphincterotomy (EST), the presence of a biliary stent, prior cholecystectomy, and past intensive care unit admission were more frequently observed in AC patients with E. faecalis and/orE. faecium than in those without such bacteria. Prior EST was identified as an independent risk factor for AC caused by E. faecalis and/or E. faecium in the multivariate analysis. Conclusions Given the intrinsic resistance of E. faecalis and E. faecium to antibiotics, clinicians should consider empirical therapy with anti-enterococcal antibiotics for patients with prior EST.

Background/Aims: Empiric antibiotics are given in combina-tion with biliary drainage for acute cholangitis but sometimes turn out to be insensitive to microorganisms in blood and bile. Clinical outcomes were compared according to sensitiv-ity to microorganisms detected in blood and bile culture to evaluate the impact of sensitivity to empiric antibiotics in cholangitis. Methods: Consecutive patients who underwent biliary drainage for acute cholangitis were retrospectively studied. Clinical outcomes such as 30-day mortality, length of hospital stay and high care unit stay, organ dysfunction and duration of fever were compared in three groups: group A (sensitive to both blood and bile culture), group B (sensitive to blood culture alone) and group C (insensitive to both blood and bile culture). Results: Eighty episodes of cholangitis were classified according to sensitivity results: 42, 32 and six in groups A, B and C. Escherichia coli and Klebsiella were two major pathogens. There were no significant differences in 30-day mortality rate (7%, 0%, and 0%, p=0.244), length of hospital stay (28.5, 21.0, and 20.5 days, p=0.369), organ dysfunc­tion rate (14%, 25%, and 17%, p=0.500), duration of fever (4.3, 3.2, and 3.5 days, p=0.921) and length of high care unit stay (1.4, 1.2, and 1.7 days, p=0.070) in groups A, B and C. Empiric antibiotics were changed in 11 episodes but clinical outcomes appeared to be non-inferior even in 31episodes of cholangitis who were on inadequate antibiotics throughout the course. Conclusions Sensitivity of empiric antibiotics was not associated with clinical outcomes in acute cholangitis.