Microbiology and risk factors for gram-positive Cocci bacteremia in biliary infections.

BACKGROUND: The rapid antibiotics treatment targeted to a specific pathogen can improve clinical outcomes of septicemia. We aimed to evaluate the clinical characteristics and outcomes of biliary septicemia caused by cholangitis or cholecystitis according to causative organisms. METHODS: We performed a retrospective cohort study in 151 patients diagnosed with cholangitis or cholecystitis with bacterial septicemia from January 2013 to December 2015. All patients showed clinical evidence of biliary tract infection and had blood isolates that demonstrated septicemia. RESULTS: Gram-negative, gram-positive, and both types of bacteria caused 84.1% (127/151), 13.2% (20/151), and 2.6% (4/151) episodes of septicemia, respectively. The most common infecting organisms were Escherichia coli among gram-negative bacteria and Enterococcus species (Enterococcus casseliflavus and Enterococcus faecalis) among gram-positive bacteria. There were no differences in mortality, re-admission rate, and need for emergency decompression procedures between the gram-positive and gram-negative septicemia groups. In univariate analysis, previous gastrectomy history was associated with gram-positive bacteremia. Multivariate analysis also showed that previous gastrectomy history was strongly associated with gram-positive septicemia (Odds ratio = 5.47, 95% CI: 1.19-25.23; P = 0.029). CONCLUSIONS: Previous gastrectomy history was related to biliary septicemia induced by gram-positive organisms. This information would aid the choice of empirical antibiotics.