Abstract: Objective To analyze the pathogenic characteristics of patients with biliary tract infection and explore their risk factors, so as to provide reference for related prevention and treatment work. Methods 792 patients with biliary tract diseases diagnosed and treated in Jinzhou Central Hospital from November 2019 to October 2020 were selected as the research objects. Bile samples from all patients with biliary tract infection were cultured, identified and drug sensitivity analyzed. The incidence rates of biliary tract infection in patients with different gender, age, body mass index, underlying diseases, types of biliary tract diseases, history of endoscopic retrograde cholangiopancreatography, and history of biliary tract surgery were observed, and the risk factors for biliary tract infection were analyzed. Results A total of 154 patients with biliary tract infection, the incidence of biliary tract infection was 19.4% （154/792）. Co-cultivation and isolation of 179 pathogenic bacteria, mainly Gram-negative bacteria （69.8%）, followed by Gram-positive bacteria （22.3%）, fungi （7.9%）. Escherichia coli （26.3%） and Klebsiella pneumoniae （19.0%） accounted for the higher proportion of Gram-negative bacteria, and Staphylococcus aureus （8.9%） and Staphylococcus epidermis （6.1%） accounted for the higher proportion of Gram-positive bacteria. Among the main Gram-negative bacteria, Escherichia coli had a high resistance rate to piperacillin （83.0%） and ciprofloxacin （70.2%）, and was sensitive to imipenem （0.0%）; Klebsiella pneumoniae had a high resistance rate to piperacillin （79.4%） and ceftazidime （67.6%）, and was sensitive to imipenem （0.0%）. Among the main Gram-positive bacteria, Staphylococcus aureus had high resistance rate to penicillin （75.0%） and erythromycin （62.5%）, and was sensitive to vancomycin （0.0%）; Staphylococcus epidermidis had a high resistance rate to penicillin （81.8%） and ampicillin （63.6%）, and was sensitive to vancomycin （0.0%） and teicolanin （0.0%）. Multivariate Logistic regression analysis showed that the older the age （OR=2.214）, malignant biliary disease （OR=2.373）, the history of endoscopic retrograde cholangiopancreatography （OR=3.979）, and the history of biliary surgery （OR=2.912） were the biliary tract risk factors for infection. Conclusion Patients with biliary tract infections have certain pathogenic characteristics, and the infections are mainly Gram-negative bacteria, effective treatment drugs can be selected according to the results of drug sensitivity tests. Biliary system infection has multiple risk factors such as the patient’s age, malignant biliary disease, history of endoscopic retrograde cholangiopancreatography, and history of biliary surgery, targeted intervention measures should be taken to reduce the incidence of infection.

Key words: Biliary tract infection, Pathogenic characteristic, Pathogen, Drug resistance, Risk factor