Distribution And Drug Resistance Of Pathogens In Bile Specimens Of The Patients With Biliary Tract Diseases

Objective: To understand the distribution, the change and the drug resistance to antibiotics of pathogens isolated from bile specimens of the patients with biliary tract diseases in recent 6 years so as to provide guidance for reasonable clinical use of antibiotics, and to explore the factors affecting positive rate of bacteria cultivation.Methods: Bile specimens collected from 326 patients with biliary tract diseases during surgery or endoscopic retrograde cholangiopancreatography(ERCP) from Jan 2010 to Dec 2015 were cultured and tested for drug sensitivity to pathogens. The correlations between clinicpathologic characteristics and the positive rates of biliary pathogenic bacteria culture were analyzed.Results:(1) Of the 140 samples collected from Jan 2010 to Dec 2012 and 186 samples collected from Jan 2013 to Dec 2015, 73 and 118 were cultured positive for pathogens, with positive rates 52.1% and 63.4%, respectively. A total of 85 and 140 strains of pathogens were isolated in the two periods, including 63(74.1%) and 96(68.6%) strains of Gram-negative bacteria, 21(24.7%) and 40(28.6%) strains of Gram-positive bacteria and 1(1.2%) and 4(2.1%) strains of fungi. The commonest pathogen was E. coli in Gram-negative strains, in which the positive rate of producing extended spectrum β-lactamases(ESBLs) strains from Jan 2013 to Dec 2015(55.0%, 22/40) was significantly higher than that from Jan 2010 to Dec 2012(19.2%, 4/26)(P<0.05). Enterococcus was the major pathogen in Gram-positive strains.(2) The positive culture rate in patients above and equal 60 years old, with symptoms of acute biliary infection, gallstones, benign biliary tract diseases, biliary surgery history, biliary ERCP history or with long operation time(≥3h) was significantly higher than that in patients lower than 60 years old, absence of acute biliary tract infection symptoms, absence of gallstones, malignant biliary diseases, absence of surgery operations history and ERCP history or short operation time(<3h)(P<0.05).(3) The drug resistant rates of Gram-negative bacteria to Imipenem and Meropenem was lowest, while the resistant rates were high to Penicillins, Quinolones, some third generation Cephalosporins and so on(>50.0%). None of the Gram-positive strains were resistant to Vancomycin, Teicoplanin and Daptomycin. They were highly resistant to Penicillins, Quinolones, Erythromycin and so on(>40.0%). The antibiotic resistant rates of Gram-negative bacilli and Gram-positive cocci increased and changed in period Jan 2013 to Dec 2015 to period Jan 2010 to Dec 2012.Conclusions:(1)Gram-negative strains remain the commonest pathogens, and E.coli and Enterococcus are dominant among the pathogens isolated from bile specimens of the patients with biliary tract diseases. The ESBLs-producing E. coli is increased and the types of pathogens in biles are changed from Jan 2010 to Dec 2012 to Jan 2013 to Dec 2015.(2) Agedness, signs of biliary infection, biliary surgery history, biliary ERCP history, gallstones and long surgery time are the factors increasing the positive rate of biliary pathogenic bacteria culture.(3) Pathogens in biliary tract have a high resistant rate to the commonly used antibiotics. It is necessary for the hospital to strengthen the detection of pathogens and reasonably use antibiotics based on the results of drug susceptibility testing.