临床分离喹诺酮耐药大肠埃希菌的耐药性及分型研究  

Resistance and genotyping of clinically isolated quinolone-resistant Escherichia coli

作　　者：周妍妍[1] 梁静雯 杜小莉[3] 马立艳[1] 于礼[4] ZHOU Yan-yan;LIANG Jing-wen;DU Xiao-li;MA Li-yan;YU Li(Beijing Friendship Hospital,Capital Medical University,Beijing 100050,China;Capital Medical University;Chinese Center for Disease Control and Prevention;Beijing Center for Disease Control and Prevention)

机构地区：[1]首都医科大学附属北京友谊医院,北京100050 [2]首都医科大学 [3]中国疾病预防控制中心 [4]北京市疾病预防控制中心

出　　处：《中国消毒学杂志》2024年第7期524-527,532,共5页Chinese Journal of Disinfection

基　　金：首都卫生发展科研专项重点攻关项目(2024-1G-3012);高层次公共卫生技术人才建设项目培养计划(学科骨干-02-016)。

摘　　要：目的研究临床分离喹诺酮耐药大肠埃希菌表型特征及分子机制。方法通过药敏试验从临床分离大肠埃希菌中筛选喹诺酮耐药株,经多位点序列分型(MLST),采用PCR检测和测序分析喹诺酮耐药决定区(QRDR)、质粒介导的喹诺酮耐药基因(PMQR)。结果所收集53株大肠埃希菌对左氧氟沙星呈中介耐药或耐药,在21个MLST分型中以ST53、ST43为主。QRDR测序显示,与敏感菌株相比,以基因Gyr A的S83L和D87N、基因Par C的S80I突变为主,分别占94.33%、79.25%、79.25%,ST53和ST43均存在此3个点突变。32.08%菌株检出PMQR基因,包括aac(6)-Ib-cr、qnr B和qnr S,62.26%菌株检出消毒剂耐药基因qac E△1。结论喹诺酮耐药大肠埃希菌的耐药机制主要与QRDR区域点突变有关,同时也应对质粒介导的耐药基因水平传递加强监测。Objective To investigate the phenotypic characteristics and molecular mechanisms of clinically isolated quinolone resistant Escherichia coli.Methods Quinolone resistant strains of Escherichia coli were screened from clinical isolates through drug sensitivity testing.After multilocus sequence typing(MLST),PCR detection and gene sequencing were used to analyze the quinolone-resistance determining regions(QRDR)and plasmid-mediated quinolone resistance(PMQR).Results The collected 53 strains of Escherichia coli showed intermediate resistance or resistance phenotype to levofloxacin.They were divided into 21 types by MLST,and ST53 and ST43 were predominant.Compared with sensitive strains,QRDR sequencing results showed that the main mutations were S83L and D87N of gene GyrA and S80I of gene ParC,accounting for 94.33%,79.25%and 79.25%,respectively.Both ST53 and ST43 showed the presence of these three site mutations.PMQR detection results showed that 32.08%of the strains detected PMQR genes of aac(6)-Ib-cr,qnrB and qnrS.In addition,the positive rate of the disinfectant resistance gene qacE△1 accounted for 62.26%.Conclusion The resistance mechanism of quinolone resistant Escherichia coli is mainly related to three site mutations in QRDR region.At the same time,monitoring of plasmid mediated resistance gene transmission should be enhanced.

关 键 词：大肠埃希菌 质粒介导的喹诺酮耐药 喹诺酮耐药决定区 多位点序列分型 

分 类 号：R372[医药卫生—病原生物学]