禽源肠聚集性大肠埃希菌中多黏菌素耐药基因mcr-1流行分布及遗传特征  

Epidemiological distribution and genetic characterization of the colistin resistance gene mcr-1 in avian-origin enteroaggregative Escherichia coli

作　　者：刘明香 张静[1] 王姗[1] 庄源[2] 陈敏[2] 丰俊 LIU Mingxiang;ZHANG Jing;WANG Shan;ZHUANG Yuan;CHEN Min;FENG Jun(Shanghai Hongkou District Center for Disease Control and Prevention,Shanghai 200082,China;Shanghai Municipal Center for Disease Control and Prevention,Shanghai 200336,China)

机构地区：[1]上海市虹口区疾病预防控制中心,上海200082 [2]上海市疾病预防控制中心,上海200336

出　　处：《中国热带医学》2024年第11期1363-1369,共7页China Tropical Medicine

基　　金：上海市加强公共卫生体系建设三年行动计划(2023—2025年)学科带头人项目(No.GWVI-11.2-XD28);虹口区疾病预防控制中心人才培养项目(No.ZXRC-2022-03);上海市虹口区卫生健康委员会医学科研课题立项建设项目(虹卫2402-25)。

摘　　要：目的了解2023年2—11月上海市虹口区冷冻生禽肉中大肠埃希菌的污染状况及其携带多黏菌素mcr-1耐药基因的分布和遗传特征。方法2023年2—11月在上海市虹口辖区的农贸市场、商店、饭店和网店等4类场所随机采集鸡、鸭、鸽子等3类生禽肉共100份进行致泻性大肠埃希菌的分离培养,应用微量肉汤稀释法进行药物敏感实验,采用实时荧光定量聚合酶链反应(polymerase chain reaction,PCR)检测mcr-1耐药基因,通过全基因组测序分析mcr-1阳性菌株的耐药基因、质粒类型、多位点序列分型(multilocus sequence typing,MLST)。分别基于单拷贝基因和最大似然法构建菌株核心基因组和MCR-1蛋白的系统进化树。借助IBM SPSS Statistics 25.0软件进行数据分析。结果在100份生禽肉样本中,29份样品中检出致泻性大肠埃希菌且均为肠聚集性大肠埃希菌(enteroaggregative Escherrichia coli,EAEC),总体检出率为29.0%(29/100)。采样地点中饭店检出率最高53.3%(8/15)。有2株(6.9%,2/29)鸡源EAEC携带mcr-1耐药基因,均为产超广谱β-内酰胺酶(extended-spectrum beta-lactamases,ESBLs)的多重耐药(multidrug resistant,MDR)菌,对环丙沙星、萘啶酸、氨苄西林、头孢噻肟、头孢唑林、四环素、庆大霉素和多黏菌素耐药率达到100.0%,此外还携带bla_(CTX-M-55)、bla_(CTX-M-14)、bla_(TEM-1)、qnrS1、tet(A)、tet(M)、sul1、sul2、fosA3、aadA2、aac(3)-IVa、aac(3)-IId、aph(4)-Ia、mph(A)、mrx等多种耐药基因。MLST分析结果显示2株阳性菌的ST型分别属于ST69和ST156,携带mcr-1的质粒类型均为InCHI2。2株禽源大肠埃希菌的核心基因组分析后发现分别与人源E.coli_042(GCA_000027125)和E.coli_SE11(GCA_000010385)亲缘类似。MCR-1蛋白与多国报道的禽源MCR-1蛋白亲缘较高。结论上海市虹口区生禽肉中肠聚集性大肠埃希菌污染较为严重,且大多菌株具有MDR特性。建议需对冷冻生禽类具有公共卫生意义的耐药基因�Objective To understand the contamination status and distribution of Escherichia coli in frozen raw poultry meat in Hongkou District,Shanghai,from February to November 2023,as well as the genetic characterization of colistin resistance gene mcr-1.Methods A total of 100 samples of different kinds of raw poultry meat,such as chicken,duck,and pigeon,were randomly collected from four types of venues including farmers′markets,stores,restaurants,and online stores in Hongkou District of Shanghai from February to November 2023.These samples were used for the isolation and culture of diarrheagenic Escherichia coli.Micro broth dilution method was used to conduct the drug susceptibility experiments,and realtime fluorescence quantitative PCR was adopted to detect mcr-1 resistance genes.Whole-genome sequencing was carried out to explore the resistance genes,plasmid type,and multilocus sequence typing(MLST)of mcr-1 positive strains.Phylogenetic trees of the core genome of the strain and MCR-1 protein were constructed based on single-copy genes and the maximum likelihood method,respectively.The data was analyzed by IBM SPSS Statistics 25.0 software.Results Among 100 raw poultry meat samples,diarrheagenic Escherichia coli was detected in 29 samples,and all of them were identified as enteroaggregative Escherichia coli(EAEC),with an overall detection rate of 29.0%(29/100).The highest detection rate was observed in restaurants(53.3%,8/15).Among them,two strains(6.9%,2/29)of chicken-origin EAEC carried mcr-1 resistance genes,both of which were multidrug-resistant strains producing extended-spectrum beta-lactamases(ESBLs),with 100.0%resistance to ciprofloxacin,nalidixic acid,ampicillin,cefotaxime,cefazolin,tetracycline,gentamicin,and polymyxin.Additionally,they carried various resistance genes including bla_(CTX-M-55),bla_(CTX-M-14),bla_(TEM-1),qnrS1,tet(A),tet(M),sul1,sul2,fosA3,aadA2,aac(3)-IVa,aac(3)-IId,aph(4)-Ia,mph(A)and mrx.MLST analysis showed that the ST types of two positive strains belonged to ST69 and ST156,respectively

关 键 词：生禽肉 肠聚集性大肠埃希菌 多黏菌素耐药基因 药物敏感性 全基因组测序 

分 类 号：R378.2[医药卫生—病原生物学]