胆汁分离病原菌分布及耐药特征分析

目的研究南京医科大学第一附属医院临床送检胆汁培养的主要病原菌分布及耐药菌感染特征，为临床胆道感染提供诊疗依据。 方法回顾性分析胆汁培养病原菌1 264株及耐药菌感染患者的临床资料，采用VITEK 2 Compact 全自动微生物鉴定及药敏系统进行细菌鉴定、药物敏感性试验，应用 WHONET 5.6进行药敏结果分析，SPSS 22.0统计软件进行耐药菌感染预后分析。 结果临床胆汁培养阳性率为32.1%，共分离阳性菌株1 264株，其中革兰阴性菌780株（61.7%），革兰阳性菌417株（33.0%），真菌67株（5.3%），菌株以大肠埃希菌（25.9%）、肺炎克雷伯菌（10.9%）、屎肠球菌（11.7%）、粪肠球菌（8.9%）为主。药敏结果显示肠杆菌科细菌对碳青霉烯类药物、氨基糖苷类药物、哌拉西林/他唑巴坦敏感性较高(＞59.9%)；非发酵菌中铜绿假单胞菌除氨苄西林/舒巴坦、复方新诺明外对其余抗菌药物敏感性较高(＞52.6%)；鲍曼不动杆菌对常用抗菌药物敏感性均＜47.4%；肠球菌属对高浓度庆大霉素、高浓度链霉素、利奈唑胺、万古霉素敏感性较高（＞63.3%），除对万古霉素天然耐药的肠球菌，暂未发现对万古霉素耐药的肠球菌。共分离碳青霉烯类耐药的肠杆菌科细菌（Carbapenem-Resistant Enterobacteriaceae CRE）50株，以肺炎克雷伯菌（62.0%）、大肠埃希菌（26.0%）为主。胆道感染CRE患者多为男性、50岁以上、有恶性肿瘤、肝移植、外伤等严重的原发疾病、有外科手术及胆汁引流史，易合并血流感染，患者预后受CRE细菌类型和有无消化道出血影响，其中碳青霉烯类耐药的肺炎克雷伯菌（Carbapenem-Resistant Klebsiella pneumoniae，CR-KPN）是胆汁培养CRE阳性患者预后不良的独立危险因素。 结论本院胆道感染病原菌以肠杆菌科细菌及肠球菌属为主，胆道CRE感染严重。临床应重点防范多重耐药菌，根据胆汁培养CRE类型可判断预后并及时干预，高危患者应主动筛查并及早去除定植耐药菌，降低胆道感染的病死率。

Analysis on the distribution of pathogen and characteristics of infection with resistant bacteria in bile culture

ObjectiveTo analyze the distribution and characteristics of drug resistanceof pathogenic bacteria in bile culture in the First Affiliated Hospital of Nanjing Medical University, so as to provide evidence for diagnosis and treatment of biliary tract infection.MethodsA total of 1 264 strains of pathogenic bacteria isolated from clinical bile specimens and clinical data of patients with infected by drug-resistant bacteria in our hospital were analyzed retrospectively. VITEK-2 Compactautomatic microbial identification and drug susceptibility systemwas used for the identification of bacteria and drug susceptibility test, and the drug sensitivity analysis was performed by WHONET 5.6 software, while SPSS 22.0 software was used to analyze the prognosis of resistant bacterial infection.ResultsA total of 1 264 positive strains were isolated from clinical bile culture with a positive culture rate of 32.1%. 780(61.7%) gram-negativestrains and 417(33.0%) and gram-positive strains were identified, with 67(5.3%) strains of fungi. Escherichia coli(25.9%), Klebsiella pneumoniae(10.9%), Enterococcus faecalis(11.7%) and Enterococcus faecalis(8.9%) were the main strains. Drug sensitivity test results showed that the sensitivity of Enterobacteriaceae bacteria to carbapenems, aminoglycosides and piperacillin/tazobactam was high(>59.9%); Pseudomonas aeruginosa was highly sensitiveto the remaining antibacterial drugs(>52.6%) except for ampicillin/sulbacillin and cotrimoxazole; the sensitivity of Acinetobacter baumannii to common antibiotics was less than 47.4%; Enterococcus is highly sensitive to high concentration of gentamicin, high concentration of streptomycin, linezolid and vancomycin(>63.3%).No vancomycin-resistant enterococcus was found except for Enterococcus naturally resistant to vancomycin. A total of 50 strains of Carbapenem-Resistant Enterobacteriaceae(CRE)were isolated, of which 62.0% were klebsiella pneumoniae and 26.0% were Escherichia coli. Most of the patients with biliary tract infection of CRE were male, aged over 50 years, with malignant tumor, liver transplantation, trauma and other serious primary diseases, with a history of surgery and bile drainage, and combinedbloodstream infection. The prognosis of patients with positive CRE cultured in bile was affected by the type of CRE bacteria and presence or absence of gastrointestinal hemorrhage, among which Carbapenem-Resistant Klebsiella pneumoniae(CR-KPN) was an independent risk factor for poor prognosis in patients with CRE cultured from bile.ConclusionEnterobacteriaceae bacteria and Enterococcus bacteria are the main pathogens for biliary tract infection in our hospital, and biliary infections of CRE are severe. In clinical practice, clinicians should focus on the prevention of multiple drug-resistant bacteria，evaluate the prognosis according to the type of CRE and provide timely intervention. In addition,high-risk patients should be actively screened forearly removal of colonization resistant bacteria, to reduce the mortality of biliary tract infections.