多重耐药大肠埃希菌获得性耐药基因检测及指标聚类分析

acquired resistance-related genes and index cluster analysis in multidrug-resistant escherichia coli

目的 调查多重耐药大肠埃希菌尿液分离株中获得性耐药相关基因和可移动遗传元件遗传标记的存在状况,并分析二者的相关性.方法 收集宁波市第一医院2008年10月-2009年3月患者尿液样本中分离的大肠埃希菌共28株,采用聚合酶链反应(pcr)法分析47种β-内酰胺类、氨基糖苷类、喹诺酮类获得性耐药基因,2种获得性抗菌制剂外排泵基因和13种整合子、转座子、插入序列、接合性质粒遗传标记,并用指标聚类分析(spss法)分析获得性耐药相关基因和可移动遗传元件遗传标记的相关性.结果 28株大肠埃希菌共检出7种β-内酰胺类获得件耐药基因、8种氨基糖苷类获得性耐药基因、1种获得性抗菌制剂外排泵基因、1种整合子遗传标记、3种转座子和插入序列遗传标记,以及2种接合性质粒遗传标记,其余46种基因均未检测到.spss法将上述阳性检出基因分成a、b两大簇.结论 本组菌株携带获得性耐药相关基因可导致对相关抗菌药物耐药,可移动遗传元件的水平转移使细菌的耐药性在同种菌株及不同种菌株间得以快速传播.spss分析提示获得性耐药相关基因和可移动遗传元件密切相关. abstract： objective to investigate the distribution of acquired resistance-related genes and markers of mobile genetic elements, and their relationships in multidrug-resistant escherichia coli. methods from october 2008 to march 2009, 28 strains of multidrug-resistant escherichia coli isolated from urine were collected from the ningbo first hospital. then, 47 kinds of acquired resistance genes to beta-lactams, aminoglycosides, quinolones, 2 kinds of acquired drug efflux gene and 13 kinds of genetic markers of mobile genetic elements: conjugal plasmids, transposons, insertion sequences, and integrons were analyzed by pcr. the index cluster analysis was used to investigate their relationships. results in 28 strains of escherichia coli, 7 kinds of acquired beta-lactam-resistance genes, 8 kinds of acquired aminoglycosideresistance genes, 1 kind of acquired drug efflux gene, 2 kinds of genetic markers of conjugal plasmids, 3 kinds of genetic markers of transposon and insertion sequences, 1 kind of genetic marker of integron were detected; but other 46 kinds of genes were not detected. two clusters, a and b, were divided by index cluster analysis depending on positive genes. conclusions in this group of escherichia coli, acquired resistance related genes may be associated with resistant phenotypes of antimicrobial agents. horizontal transfer of mobile genetic elements may bring rapid spread of resistance of bacterial pathogens, not only among the same kind of pathogens, but also among the different kinds. in addition, index cluster analysis suggests that correlation might exist between acquired resistance-related genes and mobile genetic elements.

Objective To investigate the distribution of acquired resistance-related genes and markers of mobile genetic elements, and their relationships in multidrug-resistant Escherichia coli. Methods From October 2008 to March 2009, 28 strains of multidrug-resistant Escherichia coli isolated from urine were collected from the Ningbo First Hospital. Then, 47 kinds of acquired resistance genes to beta-lactams, aminoglycosides, quinolones, 2 kinds of acquired drug efflux gene and 13 kinds of genetic markers of mobile genetic elements: conjugal plasmids, transposons, insertion sequences, and integrons were analyzed by PCR. The index cluster analysis was used to investigate their relationships. Results In 28 strains of Escherichia coli, 7 kinds of acquired beta-lactam-resistance genes, 8 kinds of acquired aminoglycosideresistance genes, 1 kind of acquired drug efflux gene, 2 kinds of genetic markers of conjugal plasmids, 3 kinds of genetic markers of transposon and insertion sequences, 1 kind of genetic marker of integron were detected; but other 46 kinds of genes were not detected. Two clusters, A and B, were divided by index cluster analysis depending on positive genes. Conclusions In this group of Escherichia coli, acquired resistance related genes may be associated with resistant phenotypes of antimicrobial agents. Horizontal transfer of mobile genetic elements may bring rapid spread of resistance of bacterial pathogens, not only among the same kind of pathogens, but also among the different kinds. In addition, index cluster analysis suggests that correlation might exist between acquired resistance-related genes and mobile genetic elements.