猪源氟喹诺酮耐药大肠杆菌通过接合水平传递耐药性的研究  

Investigation of Antimicrobial Agents Resistance Transferred Horizontally in Fluoroquinolone Resistant Escherichia coli from Swine

作　　者：王宏栋[1] 徐国锋[1] 矫薇薇 张秀英[1] 

机构地区：[1]东北农业大学动物医学学院,哈尔滨150030

出　　处：《畜牧兽医学报》2016年第4期805-811,共7页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：哈尔滨市科技局科技创新人才基金(2013RFXXJ035)

摘　　要：为研究猪源大肠杆菌中可移动质粒在氟喹诺酮类药物耐药性水平传播机制中的作用,作者对氟喹诺酮耐药且PMQR基因阳性的大肠杆菌进行接合试验,并对所得接合子采用微量肉汤稀释法测定其对8种常见药物的最小抑菌浓度(MIC),针对质粒介导的氟喹诺酮耐药基因(PMQR)设计特异性引物对接合子进行PCR扩增。研究结果显示,41株氟喹诺酮耐药且PMQR基因阳性的供体菌共接合成功16株细菌,接合成功率高达39%,接合子与受体菌J53相比,均呈现一定的耐药表型,与供体菌相比,87.5%的接合子存在耐药谱型的变化,并且存在丢失一种药物耐药性,产生另一种药物耐药性的现象,PCR结果显示,接合子与供体菌相比,基因型有所减少,接合子中qnrS基因接合成功率最高,12.5%的接合子发生oqxA、oqxB和qnrS的共转移。本研究表明不同的PMQR基因在可移动质粒介导耐药性水平传播的过程中接合成功率存在差异,不同的PMQR基因有可能位于不同的可移动质粒上,通过比较接合前后供体菌和受体菌耐药表型的变化,尤其是PMQR基因检出率的变化,可以初步确定,可移动性质粒在大肠杆菌耐药性水平传播的过程中起到了非常重要的作用。In order to investigate the role of mobile plasmids in the horizontal transmission mechanism of drug resistance in Escherichia coli isolated from pigs,the conjugation experiments of fluoroquinolone resistance and PMQRgenes positive Escherichia coli were carried out,the minimum inhibitory concentration（MIC）of 8kinds of common drug in transconjugants were figured by using broth micro dilution method and the plasmid mediated quinolone resistance gene（PMQR）were detected by PCR methods with specific primers designed after the conjugation experiments.The results showed that 16 strains of bacteria were joined successfully within 41 strains of fluoroquinolone resistance and PMQRgenes positive donors,successful rate of conjugation experiments was up to 39%,transconjugants showed kinds of resistant phenotypes compared with J53 strain through testing the figure of MIC values,and compared with donor strains,87.5% of the transconjugants reveals changes of drug resistance patterns and the phenomenon of missing a drug resistance with obtaining another drug resistance,the results of PCR showed the decline of gene phenotypes compared with donor strains,qnrSgene revealed the highest successful conjugationrate,the genes of oqxA and oqxB can transferred in the same mobile plasmid,12.5% of the transconjugants displayed that the genes of oqxA,oqxBand qnrScan be transferred by the same mobile plasmid.The results above suggest that different PMQR genes show different success rates in the process of conjugation jointing with mobile plasmid which mediated resistance genes transferred horizontally in strains,which suggest the different PMQRgenes may be located in the different mobile plasmid,by comparing the changes of drug resistance and gene phenotypes before and after conjugation experiments,especially the detection rate of PMQRgene,it can be preliminarily confirmed that the mobile plasmids play a very important role in the process that antimicrobial agents resistance genes are transferred horizontally in Escherichia coli strain

关 键 词：大肠杆菌 质粒 接合子 水平传播 

分 类 号：S852.612[农业科学—基础兽医学]