【作者】 齐亚银； 剡根强；

【机构】 石河子大学动物科技学院；

【摘要】 为查明分离株粪/屎肠球菌中Ⅰ类整合子的遗传标记,弄清Ⅰ类整合子所携带的耐药基因盒种类。本试验采用PCR方法测定分离株粪/屎肠球菌中Ⅰ类整合子遗传标记(5’端Ⅰ类整合酶基因和3’端qacE△l-sull基因),分析比对其核苷酸序列的差异;对Ⅰ类整合子可变区所携带的耐药基因盒进行克隆测序,确定其携带的耐药基因盒种类,查明分离株中携带的Ⅰ类整合子基因结构。结果,400株粪/屎肠球菌中Ⅰ类整合酶基因阳性率高达64.5%(258/400),qacE△1-sull基因阳性率高达56.5%(226/400),且携带有aadA5(甲氧苄啶耐药基因)-dfrA1 7(链霉素、壮观霉素耐药基因)的耐药基因盒以及500bp长度的未知耐药基因盒。226株分离株中携带的Ⅰ类整合子具有5’端、3’端以及耐药基因盒完整结构,其中32株分离株携带的Ⅰ类整合子只具有5’端的整合酶基因结构。结果表明鉴于Ⅰ类整合子遗传标记(3’-端的Ⅰ类整合酶基因及5’端的qacE△1-sull基因)对不同耐药基因的水平传播,以及携带有aadA5及dfrA17基因盒对多种耐药基因传播的可能性,提示应加强动物源性细菌中Ⅰ类整合子的监测,以降低耐药基因在不同菌株间的传播以及由动物性食品给人传播的风险性。更多还原

【Abstract】 The purpose was to detect the genetic marker of integron Ⅰ,and to make clear the variety of gene-cassettes which existed in integron Ⅰ.Genetic marker of integron Ⅰ which were made up of the integrase Ⅰ and genetic markers of qacE△1-sull were detected by PCR,then cloned,sequenced and homologous analysis of sequences.Ⅰn addition,variable region of integron Ⅰ was cloned and sequenced in order to determine the species of gene-cassettes and the genetic structure.The results showed that the positive of integrase Ⅰ gene was 64.5%(258/400) and qacEA1-sull gene was 56.5%(226/400)corresponding.The gene-cassettes of aadA5-dfrA17 and the unknown length of 500 bp were detected from different isolates of Enterococcus faecalis and Enterococcus faecium.Among 400 stains selected,there were 226 isolates including genetic marker of integron Ⅰ and 32 isolates only containing the integrase Ⅰ except qacE△1-sull gene.The conclusion showed that the genetic marker which was made up of the integrase Ⅰ and genetic markers of qacE△1-sull could horizontal transmit different drug resistance gene,and had a probability which the gene-cassettes of aadA5 and dfrA17 could spread multiple drug resistance gene.We should strengthen monitoring of integron Ⅰ from the animal-derived bacterium,in order to block the spread of resistance gene from animals to peoples.更多还原