【摘要】 目的 监测2017年至2020年临床分离得到大肠埃希菌中多黏菌素耐药mcr-1阳性菌株的分子流行病学特征。方法 使用聚合酶链反应技术筛查mcr-1阳性菌株从临床分离的1 518株大肠埃希菌。采用16SrRNA验证所有纳入分析的mcr-1阳性菌株的菌种。使用微量肉汤法与琼脂二倍稀释法进行抗菌药物敏感实验。所有mcr-1阳性菌株通过多位点序列分型(MLST)进行同源性分析。结果 在1 518株临床分离大肠埃希菌中，检测到14株(0.92%)携带mcr-1基因的大肠埃希菌。微量肉汤法显示14株mcr-1阳性菌株均对多黏菌素耐药。16SrRNA验证14株mcr-1阳性菌株类型均为大肠埃希菌。14株阳性菌株对临床常用抗菌药物中的第三、四代头孢菌素、单环β-内酰胺类以及喹诺酮类等都表现出较高的耐药率，尤其阳性菌株对头孢唑啉、头孢呋辛、头孢噻肟、头孢曲松、头孢他啶、头孢哌酮和头孢吡肟的耐药率在57.1%～92.9%,对氨曲南的耐药率为64.3%,对环丙沙星和左氧氟沙星的耐药率达到92.9%;14株mcr-1阳性菌对β内酰胺类酶抑制剂复合制剂和碳青霉烯类药物(亚胺培南、美罗培南和厄他培南)的耐药率较低，均为14.3%;14株mcr-1阳性菌对庆大霉素和阿米卡星的耐药率为57.1%和21.4%;对四环素和米诺环素耐药率分别为85.7%和64.3%,但是均对替加环素表现为敏感。MLST分析显示14株mcr-1阳性菌株分别获得14种不同STs分型。对14株阳性菌株进行聚类分析显示较为分散，相似度低于60%。结论 临床分离的大肠杆菌mcr-1阳性菌株的检出率低于往年。14个不同的ST分型显示mcr-1阳性大肠埃希菌的遗传多样性。应进一步关注阳性菌株的多重耐药表型和传播。更多还原

【Abstract】 Objective To monitor molecular epidemiological characteristics of mcr-1-positive strains in colistin resistant Escherichia coli(E. coli.) in 2017-2020. Methods mcr-1-positive isolates was screened by polymerase chain reaction(PCR) technology from clinical separation of 1 518 E. coli. The mcr-1-positive isolates of all inclusion analysis were verified by 16 SrRNA. Antimicrobial susceptibility was determined by broth microdilution method and agar two-fold dilution. All mcr-1-positive strains analyzed by Multilocus Sequence Typing(MLST). Results Among 1 518 strains of clinically isolated E. coli, 14(0.92%) strains of E. coli carrying mcr-1 gene were detected. The resistance of 14 mcr-1-positive strains to colistin was determined by broth microdilution method. All mcr-1-positive strains were identified as E. coli by 16SrRNA.And 14 strains showed high resistance to cephalosporins,monocyclic β-lactams and quinolones,especially to cefazolin,cefuroxime, cefotaxime, ceftriaxone, ceftazidime, cefoperazone and cefepime. The resistance rate to aztreonam was 64. 3%; the resistance rate to ciprofloxacin and levofloxacin was 92. 9%; the resistance rates of 14 mcr-1-positive bacteria to β-lactamase inhibitors and carbapenem drugs( imipenem,meropenem and erapenem) were14. 3%,and the resistance rates of 14 mcr-1-positive bacteria to gentamicin and amikacin were 57. 1% and21. 4%,respectively. The resistance rates to tetracycline and minocycline were 85. 7% and 64. 3% respectively,but were sensitive to tigecycline. And 14 different ST genotypes were obtained by MLST analysis of 14 mcr-1 positive strains. The clustering of 14 positive strains showed that the similarity coefficient was less than 60%. Conclusion The detection rate of E. coli mcr-1-positive strains isolated from clinic was less than that in previous years. And 14different ST revealed genetic diversity. Further attention should be given to the multidrug-resistance phenotype and transmission of positive strains.更多还原