大肠埃希菌获得性耐药基因检测及指标聚类分析  

Detection and hierarchical cluster analysis of acquired resistance genes in Escherichia coli

作　　者：邹正平[1] 赵旺胜[2] 金辉[3] 翁幸鐾[4] 糜祖煌[5] 

机构地区：[1]金坛市中医医院检验科,江苏金坛213200 [2]南京医科大学第一附属医院医学检验科,江苏南京210029 [3]东南大学公共卫生学院流行病与卫生统计教研室,江苏南京210010 [4]宁波市第一医院检验科,浙江宁波315000 [5]无锡市克隆遗传技术研究所,江苏无锡214026

出　　处：《中华医院感染学杂志》2012年第13期2736-2739,共4页Chinese Journal of Nosocomiology

基　　金：江苏省实验诊断学重点实验重大项目(XK200731)

摘　　要：目的调查大肠埃希菌45种获得性耐药基因和7种可移动遗传元件遗传标记基因的存在状况,以及获得性耐药基因和可移动遗传元件遗传标记基因的相关性。方法收集南京医科大学第一附属医院2006年3月-2008年10月患者尿液标本中分离的大肠埃希菌共60株,采用聚合酶链反应(PCR)法分析45种β-内酰胺类、氨基糖苷类、喹诺酮类获得性耐药基因和7种整合子、转座子、插入序列、接合性质粒遗传标记基因,并用指标聚类分析(SPSS法),分析β-内酰胺类、氨基糖苷类和喹诺酮类获得性耐药基因与整合子、转座子、插入序列、接合性质粒遗传标记基因的相关性。结果 60株大肠埃希菌共检测到10种获得性耐药基因(包括3种β-酰胺类获得性耐药基因、6种氨基糖苷类获得性耐药基因、1种喹诺酮类获得性耐药基因);且7种可移动遗传元件遗传标记基因均有检出,包括1种整合子基因遗传标记基因、4种转座子和插入序列基因遗传标记基因、两种接合性质粒遗传标记基因,其余35种基因均未检测到;SPSS法将上述阳性检出基因分成A和B两大簇群。结论大肠埃希菌对抗菌药物的耐药表型与获得性耐药基因相关,且可移动遗传元件的水平转移使细菌的耐药性在同种细菌菌株之间甚至不同种细菌菌株之间得以快速传播;获得性耐药基因与可移动遗传元件遗传标记基因的指标聚类分析显示,在A簇群中,aadA5与intⅠ1、CTX-M-55与ISEcp1、TEM-1与IS26较为相关,并有可能位于携带traA、trbC性毛基因的接合性质粒上,在B簇群中,aac(6′)-Ⅰb与Tn21较为相关。OBJECTIVE To investigate the distribution of 45 kinds of acquired resistance genes and 7 kinds of genetic markers of mobile genetic elements,and the correlation between acquired resistance genes and genetic markers of mobile genetic elements in Escherichia coli.METHODS From Mar 2006 to Oct 2008,a total of 60 strains of E.coli isolated from urine were collected from the First Affiliated Hospital of Nanjing Medical University,China.Then,45 kinds of acquired resistance genes to beta-lactams,aminoglycosides,quinolones,and 7 kinds of genetic markers of mobile genetic elements：conjugal plasmids,transposons,insertion sequences,and integrons were analyzed by PCR.And hierarchical cluster analysis was performed to investigate the correlation between acquired resistance genes and genetic markers of mobile genetic elements.RESULTS Of 60 strains of E.coli,totally 10 kinds of acquired resistance genes were detected（including 3 kinds of acquired beta-lactam-resistance genes,6 kinds of acquired aminoglycoside-resistance genes,1 kind of acquired quinolone-resistance genes）,and all the 7 kinds of genetic markers of mobile genetic elements were detected（including 2 kinds of conjugal plasmids,4 kinds of transposon and insertion sequences,1 kind of integron）,however the other 35 kinds of genes could not be detected;two clusters,A and B,were divided by hierarchical cluster analysis depending onpositive genes. CONCLUSIONThe acquired resistance genes play a role in resistant phenotypes of E.coli to antimicrobialagents.And the horizontal transfer of mobile genetic elements brings rapid spread of resistance not only among the same species of pathogens but also among the different species of pathogens as well;in addition,hierarchical cluster analysis shows that correlation might exist between aadA5 and intⅠ1,CTX-M-55 and ISEcp1,TEM-1 and IS26 in cluster A,these genes might exist in conjugal plasmids which harbor traA and trbC,and the correlationmight exist between aac（6′）-Ⅰb and Tn21 in cluster B.

关 键 词：大肠埃希菌 获得性耐药基因 可移动遗传元件 指标聚类分析 多药耐药 

分 类 号：R378.21[医药卫生—病原生物学]