2017-2018年包头地区耐喹诺酮大肠埃希菌临床分离株的耐药特征与机制分析  

Analysis of drug resistance characteristics and mechanisms of quinolones-resistant Escherichia coli from clinical isolates in Baotou 2017-2018

作　　者：李翠翠 胡同平[1] 张利霞[1] LI Cui-cui;HU Tong-ping;ZHANG Li-xia(The First Affiliated Hospital of Baotou Medical College,Baotou,Inner Mongolia 014010,China)

机构地区：[1]内蒙古科技大学包头医学院第一附属医院检验科,内蒙古包头014010

出　　处：《中华医院感染学杂志》2021年第4期518-524,共7页Chinese Journal of Nosocomiology

基　　金：内蒙古自治区自然科学基金资助项目(2016MS(LH)0824);包头医学院科学研究基金项目—扬帆计划基金资助项目(BYJJ-YF201691)。

摘　　要：目的了解内蒙古包头地区临床分离的耐喹诺酮大肠埃希菌的耐药特征以及机制。方法收集2017-2018年内蒙古包头地区11所参与全国细菌耐药监测网医院的大肠埃希菌临床分离株,采用纸片扩散法或自动化仪器法按统一技术方案进行药敏试验,采用酶抑制剂增强试验测定超广谱β-内酰胺酶(ESBLs),分析病原菌耐药性。并且随机从大肠埃希菌喹诺酮类耐药(环丙沙星或/和左氧氟沙星耐药)组中筛选60株作为试验菌株,采用微量肉汤稀释法测定环丙沙星最低抑菌浓度(MIC)值,采用聚合酶链反应检测GyrA、GyrB、ParC、ParE、qnrA、qnrB、qnrS、aac(6′)-Ib以及qepA基因,限制性酶切反应确定aac(6′)-Ib-cr基因型。结果共收集上述医院非重复大肠埃希菌临床分离株4 262株。耐喹诺酮大肠埃希菌分离率居前3位的医院分别为包头市肿瘤医院(79.37%)、内蒙古包钢医院(74.45%)和包头市第八医院(72.52%);前3位科室分别为泌尿科(90.74%)、呼吸内科(87.58%)和肿瘤科(77.87%);前3位标本分别为尿液(73.77%)、痰液等呼吸道标本(65.63%)和引流液(63.27%)。4 262株大肠埃希菌中喹诺酮类耐药组和喹诺酮类非耐药组占比分别为66.31%和33.69%,喹诺酮类耐药组对绝大部分所测抗菌药物的耐药率和产ESBLs的检出率均高于喹诺酮类非耐药组(P<0.05)。60株试验菌株:GyrA、GyrB、ParC和ParE基因的阳性率均为100.00%;GyrA、ParC和ParE亚基突变发生率均为100.00%,GyrB亚基突变发生率为16.67%;发生最多的氨基酸取代种类是Ser83→Leu(100.00%),其次依次为Ser80→Ile(96.67%)和Asp87→Asn(91.67%);质粒介导的喹诺酮类耐药(PMQR)基因阳性率为18.33%,其中检出率由高到低分别为aac(6′)-Ib-cr基因(15.00%)、qnrS基因(6.67%)和qepA基因(3.33%)。在GyrA亚基双突变的基础上,发生ParC亚基单位点(Ser80或Glu84)突变的菌株对环丙沙星的MIC值多在32~64μg/ml范围内;发生ParC亚基双位点(Ser80和Glu84)OBJECTIVE To analyze the drug resistance characteristics and mechanisms of quinolones-resistant Escherichia coli from clinical isolates in Baotou, Inner Mongolia. METHODS E.coli clinical isolates from 11 hospitals taking part in the China Antimicrobial Resistance Surveillance System(CARSS) in Baotou, Inner Mongolia from 2017 to 2018 were collected. Antimicrobial susceptibility test was carried out by the paper diffusion method or the automated instrument method according to a unified protocol. Enzyme inhibitor enhancement confirmation test was used to detect hyperspectral β-lactamases(ESBLs) and the drug resistance of pathogens were analyzed. Sixty strains were randomly selected from the quinolone-resistant(ciprofloxacin or/and levofloxacin resistant) E.coli group as experimental strains. The minimum inhibitory concentration(MIC) of ciprofloxacin was determined by the micro broth dilution method. Polymerase chain reaction(PCR) was used to detect GyrA, GyrB, ParC, ParE, qnrA, qnrB, qnrS, aac(6′)-Ib, and qepA genes. Aac(6′)-Ib-cr gene was determined by restriction enzyme digestion reaction. RESULTS A total of 4 262 non-repetitive E.coli clinical isolates were collected from the above hospitals. The top 3 hospitals for quinolone-resistant E.coli isolation rates were Baotou Cancer Hospital(79.37%), Inner Mongolia Baogang Hospital(74.45%), and Baotou No. 8 Hospital(72.52%). The top 3 departments for quinolone-resistant E.coli isolation rates were urology(90.74%), respiratory medicine(87.58%), and oncology(77.87%). The top 3 specimens for quinolone-resistant E.coli isolation rates were urine(73.77%), sputum and other respiratory specimens(65.63%), and drainage fluid(63.27%). Among the 4262 strains of E.coli, the quinolone-resistant group and the quinolone-non-resistant group accounted for 66.31% and 33.69%, respectively. The resistance rate to most of the tested antimicrobial agents and the detection rate of producing ESBLs in the quinolone-resistant group were significantly higher than those in the quinolone non-

关 键 词：喹诺酮类抗菌药物 大肠埃希菌 喹诺酮类耐药决定区 质粒介导的喹诺酮类耐药 

分 类 号：R378[医药卫生—病原生物学]