产ESBLs大肠埃希菌的耐药性与TEM型耐药基因的关系探讨

The Relationship between Drug-resistance and TEM Drug-resistant Gene in ESBLs Producing Escherichia coli

目的了解西南医科大学附属医院产超广谱β-内酰胺酶(ESBLs)大肠埃希菌耐药情况及TEM耐药基因的流行类型。方法收集2014年7月-2014年11月西南医科大学附属医院分离到的93株非重复致病性大肠埃希菌菌株,1.采用K-B法进行药敏实验。2.双纸片法进行ESBLs确证实验。3.聚合酶链反应(PCR)法检测TEM基因阳性菌株,测序比对确定基因型。结果 1.大肠埃希菌对哌拉西林、第二代头孢菌素、头孢噻肟、喹诺酮类(莫西沙星除外)、氨基糖苷类(阿米卡星除外)的耐药率高(46.24%-78.49%),对β-内酰胺酶类/酶抑制剂复方制剂、头霉素类、阿米卡星、头孢他啶耐药率低(1.08%-17.2%)。全敏、单耐、双耐、多耐菌株分别占4.3%、5.38%、19.35%、70.97%,未检出全耐药菌株。2.ESBLs阳性菌株55株(59.14%),其中多重耐药菌株53株(96.37%),双重耐药菌株2株(3.63%);ESBLs阳性菌株中检出TEM阳性32株(58.18%),主要分布于多重耐药菌株30株(93.75%)。3.经基因测序比对分析,所有的TEM阳性菌株均为TEM-1型β-内酰胺酶。结论 TEM型ESBLs在多重耐药菌株中检出率高,ESBLs阳性且携带TEM耐药基因是本地区大肠埃希菌多重耐药的主要机制。

To investigate the drug resistance of extended-spectrum beta-lactamase(ESBLs)-producing Esche.ichia coli and the epidemic type of TEM resistance gene in clinical isolated Escherichia coli.93non-repetitive pathogenic strains of Escherichia coli were isolated and collected during the period from July,2014to November,2014in the Affiliated Hospital to Southwest Medical University;K-B method was applied in drug sensitivity test while double-disk diffusion method was applied in the confirmatory test of ESBLs;the TEM gene positive strains were screened by polymerase chain reaction(PCR)and the genotypes were determined by sequencing.1.Escherichia coli was of the high drug resistance rate(46.24%-78.49%)to the piperacillin,second-generation cephalosporins,cefotaxime,quinolones(except moxifloxacin)and aminoglycosides(except amikacin)while was of low drug resistance rate(1.08%-17.2%)toβ-lactamase/enzyme inhibitors compound preparation,cephamycins,amikacin and ceftazidime;the total-sensitive,single drug-resistant,double drug-resistant and multiple drug-resistant strains took up4.3%,5.38%,19.35%and70.97%respectively,and no pan-resistant strains were detected;2.out of93strains of Escherichia coli,55ESBLs-positive strains were detected,the detection rate was59.14%,including53multiple drug resistant strains(96.37%)and2double drug-resistant strains(3.6%);out of the55ESBLs-positive strains,32TEM positive strains(58.18%)were detected,including30multiple drug-resistant strains,the detection rate was93.75%.;3.the sequencing results indicated that all the32TEM-positive strains wereβ-Lactamase TEM-1.TEM-type ESBLs is of high detection rate in multiple drug-resistant strains,and ESBLs positive with TEM drug-resistant gene is the key mechanism for the multiple drug resistance of Escherichia coli.