移动性多黏菌素耐药基因介导的大肠埃希菌药敏特点与同源性分析  

Characteristics and homology analysis of drug sensitivity of Escherichia coli mediated by the mobile polymyxin resistance gene

作　　者：赵树龙 宋爽 刘乐 许晶晶 徐银海 康海全 ZHAO Shulong;SONG Shuang;LIU Le;XU Jingjing;XU Yinhai;KANG Haiquan(Department of Clinical Laboratory,the Affiliated Hospital of Xuzhou Medical University,Xuzhou 221002,Jiangsu;School of Medical Technology,Xuzhou Medical University,Xuzhou 221004,Jiangsu,China)

机构地区：[1]徐州医科大学附属医院检验科,江苏徐州221002 [2]徐州医科大学医学技术学院,江苏徐州221004

出　　处：《临床检验杂志》2024年第5期327-331,共5页Chinese Journal of Clinical Laboratory Science

基　　金：江苏省六大人才高峰项目(WSN-091);江苏省卫健委科研项目(Z2021009);徐州医科大学附属医院院级科研项目(2021ZA43)。

摘　　要：目的分析多黏菌素耐药大肠埃希菌的耐药机制、药敏特点及其同源性,为有效预防和控制其暴发及流行提供分子流行病学依据。方法收集2016年5月至2022年6月分离自临床的多黏菌素耐药大肠埃希菌,应用PCR技术筛选移动性多黏菌素耐药基因(mobile colistin resistance,MCR),采用微量肉汤稀释法测定最小抑菌浓度。收集患者的临床资料,利用脉冲场电泳技术(PFGE)对收集到的菌株进行同源性分析并对其中1株进行全基因组测序分析。结果分离并鉴定出4株携带有MCR-1基因的多黏菌素耐药大肠埃希菌,4株菌株除了对替加环素均敏感外,对于临床常见的绝大多数抗生素均表现出不同程度的耐药。临床资料分析均未发现患者有多黏菌素使用史。该4株菌可分为2种类型,其中A型3株,B型1株。对其中1株菌进行全基因组测序分析发现MCR-1基因位于约70 kb的质粒上。结论携带MCR-1基因的多黏菌素耐药大肠埃希菌具有克隆传播的潜在威胁,对临床常见抗生素均表现出较高的耐药性,为临床治疗带来极为严重的挑战,需要加强防护措施,防止其暴发流行。Objective To analyze the resistance mechanism,characteristics of drug sensitivity,and homology of polymyxin resistant Escherichia coli,and provide molecular epidemiological basis for the effective prevention and control of its outbreak and epidemic.Methods The strains of polymyxin resistant Escherichia coli isolated from our hospital during May 2016 and June 2022 were collected.The PCR technology was used to screen for the mobile colistin resistance(MCR)gene and the micro broth dilution method was used to determine the minimum inhibitory concentration.The clinical data of the patients were collected.The homology of the collected strains was analyzed by the pulsed field gel electrophoresis(PFGE).One of the strains was performed whole genome sequencing.Results Four strains of polymyxin resistant Escherichia coli carrying the MCR-1 gene were isolated and identified.Except for being sensitive to tigecycline,all four strains showed varying degrees of resistance to the vast majority of clinically common antibiotics.Clinical data showed that no polymyxin was used in the patients with polymyxin resistant Escherichia coli.The four strains of bacteria could be divided into two types,including three strains of type A and one strain of type B.The whole genome sequencing analysis of one of the bacteria revealed that the MCR-1 gene was located on a plasmid with a size of 70 kb.Conclusion The Escherichia coli carrying the MCR-1 gene has a potential threat to clone transmission and exhibits high resistance to common antibiotics in clinical practice,posing a serious challenge to clinical treatment.Therefore,it is necessary to strengthen protective measures to prevent its outbreak and epidemic.

关 键 词：大肠埃希菌 移动性多黏菌素耐药基因 脉冲场电泳 耐药 同源性分析 

分 类 号：R446.5[医药卫生—诊断学]