多重耐药福氏志贺菌相关耐药基因的指标聚类分析

摘要

Objective To investigate the antimicrobial characteristics of shigella flexneri and to analyze the correlation between acquired resistance genes and mobile genetic elements.Methods 139 strains of shigella flexneri collected from each district of Centers for Disease Control and Prevention in Shanghai from 2010 to 2014 were recovered.The K-B method was used to determine the susceptibility of the strains to 13 antibiotics.And then 17 kinds of acquired resistance genes to β-lactams, sulfonamides, aminoglycosides and 7 kinds of genetic markers of mobile genetic elements were analyzed by PCR.Index cluster analysis was performed to explore the correlation between them.Results Among 139 strains of Shigella flexneri,3 kinds of genetic markers of mobile genetic elements,ISEcp1,intI1 and trbC,3 kinds of acquired β-lactam-resistance genes,CTX-M,OXA and TEM,2 kinds of acquired aminoglycoside-resistance genes,ant(3")-I and aac(6′)-Ib, 1 kind of overlapping gene of quaternary ammonium disinfectant and sulfonamides, qacEΔ1-sull and 1 kind of sulfamethoxazole/trimethoprim-resistant gene, dfrA1 were detected.The resistence genes,OXA,ant(3")-I and drfA1 were highly related with each other,which were mediated by Class 1 integron.TEM,qacEΔl-sull and aac(6′)-Ib were highly related with each other,which were mediated by trbC.Conclusion Acquired multidrug resistance gene transfer mediated by a variety of mobile genetic elements may have largely contributed to the spreading of resistant strains of Shigella.%目的 探讨福氏志贺菌的耐药性及其获得性耐药相关基因和可移动遗传元件的携带状况,并分析两者的相关性.方法 选取并复苏2010至2014年上海市各区县疾病预防与控制中心上送的139株福氏志贺菌,采用K-B法测定菌株对13种抗生素的敏感性,同时用PCR检测17种β-内酰胺类药物耐药基因、季铵盐消毒剂与磺胺耐药重叠基因、甲氧苄啶-磺胺甲68970rn唑耐药基因、氨基糖苷类修饰酶耐药基因及7种可移动遗传标记,用指标聚类分析法分析获得性耐药基因和可移动元件遗传标记存在状况的相关性.结果 139株福氏志贺菌共检测到ISEcp1、intI1和trbC 3种可移动遗传元件的遗传标记;CTX-M、OXA和TEM 3种β-内酰胺类药物耐药相关基因;ant(3")-I和aac(6′)-Ib2种氨基糖苷类修饰酶基因;1种季铵盐消毒剂与磺胺耐药重叠基因qacEΔ1-sull和1种甲氧苄啶-磺胺甲68970rn唑相关基因dfrA1.指标聚类分析显示,OXA、ant(3")-I和drfA1这3个基因高度相关,并同时被Ⅰ类整合子intI1介导;TEM、qacEΔl-sull和aac(6′)-Ib这3个基因高度相关,并同时被另一个移动元件即接合性质粒trbC介导.结论 多种可移动遗传元件介导的获得性耐药基因水平转移可能在很大程度上导致了志贺菌耐药株的不断蔓延.