胆道感染大肠埃希菌的耐药性及喹诺酮类药物的耐药机制研究  

Drug resistance of E.coli from biliary tract infections and mechanisms of its resistance to quinolones

作　　者：孙国华 刘小香[2] 孙爱华[2] 

机构地区：[1]浙江省义乌市稠州医院外科,322000 [2]浙江医学高等专科学校,杭州市310053

出　　处：《中华全科医学》2015年第6期884-886,共3页Chinese Journal of General Practice

基　　金：浙江省卫生高层次创新人才培养工程项目([2012]241);浙江医学高等专科学校学科持续建设计划项目(2013XKCX03)

摘　　要：目的了解胆道感染病原菌分布及耐药性,研究大肠埃希菌gyr A和par C基因的QRDR区突变和耐药的相关性。方法留取2009年1月—2013年12月医院肝胆外科施行胆道手术的257例患者的术中胆汁,其中胆囊胆汁219例,胆管胆汁38例,进行细菌培养。纸片法和琼脂稀释法进行大肠埃希菌药敏试验和MICs检测;PCR扩增目的基因并测序。结果胆汁培养阳性率为30.0%（77/257）,检测到大肠埃希菌23株最常见。大肠埃希菌临床菌株对亚胺培南100%敏感,对加酶抑制剂复合抗菌药物耐药率低于20%。环丙沙星和左氧氟沙星耐药率分别为65.2%和60.7%。8株对两种喹诺酮药物均敏感的菌株仅有1株gyr A基因存在突变,14株对两种喹诺酮药物均耐药的菌株,6株只存在gyr A基因突变菌株MICs≤16 mg/L,8株同时存在gyr A和par C基因突变菌株中有7株对两种喹诺酮药物的MICs为16-≥128 mg/L。结论大肠埃希菌为本地区胆汁培养最常见病原菌,gyr A和par C基因突变在大肠埃希菌对喹诺酮类药物耐药中起重要作用,par C基因突变与耐药程度密切相关。Objective To study the bacterial distribution of biliary tract infections, drug resistance and the relationship between quinolone resistance and mutations of QRDR of gyrA and/or parC genes in E. coil. Methods From Jan. 2009 to Dec. 2013,257 cases of bile samples after bile surgery were studied,including 219 samples from gallbladder and 38 from bile duct. The bacteria culture were analyzed. The susceptibility test and MICs were detected by K-B disk diffusion method and agar dilution test, respectively. The fragments of QRDR of gyrA and parC were amplified and these fragments were se- quenced. Results The positive culture incidence of bile samples was 30.0% （77/257）. E. coli was the most common gram-negative strains, there were 23 isolates ; In 23 isolates of E. coli, there were not found resistant to imipenem, the re- sistance rates were all lower than 20% to drug with enzyme inhibitors. The resistance rates of ciprofloxacin and levofloxa- cin were 65.2% and 60.7% ,respectively. Only 1 of 8 sensitive isolates to two quinolones had mutation in gyrA gene;In 14 resistance isolates to two quinolones,6 isolates had mutation in gyrA gene with MICs ≤ 16 mg/L, and 8 isolates had mutations in gyrA and parC genes, which 7 isolates MICs ranging from 16 to ≥ 128 mg/L. Conclusion E. coli is the main bacterial from bile culture in Yiwu city. Mutations in gyrA and parC genes play an im portant role in the development of quinolone resistance in E. coli. Mutation of parC gene are closely associated with high quinolone-resistance.

关 键 词：胆道感染 大肠埃希菌 耐药 gyrA/parC基因 突变 

分 类 号：R575.6[医药卫生—消化系统] R378.2[医药卫生—内科学]