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

发布时间：2018-01-02 03:11

本文关键词：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　出处：《畜牧兽医学报》2016年04期 　论文类型：期刊论文

【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。
[Abstract]:In order to study the role of movable plasmid in porcine Escherichia coli in the horizontal transmission mechanism of fluoroquinolones drug resistance, the authors carried out conjugation tests on fluoroquinolone-resistant and PMQR positive Escherichia coli. The minimal inhibitory concentration (MIC) of the conjugate to 8 common drugs was determined by broth dilution method. Specific primers were designed for PCR amplification of plasmide-mediated fluoroquinolone resistance gene (PMQR). Sixteen of 41 strains of fluoroquinolone-resistant and PMQR gene positive donor bacteria were successfully conjugated, and the conjugation success rate was as high as 39%. Compared with the receptor strain J53, the conjugate showed a certain phenotype of drug resistance. Compared with the donor bacteria, 87.5% of the conjugates had the change of drug resistance spectrum, and the phenomenon of losing one drug resistance and producing another drug resistance showed by PCR results. Compared with the donor bacteria, the genetype of the conjugate was reduced, and the highest successful rate of conjugation of qnrS gene in the conjugate was 12.5% of the conjugates occurred oqxA. The co-transfer of oqxB and qnrS. This study shows that the successful rate of conjugation of different PMQR genes in the process of transportable plasmid mediated drug resistance level transmission is different. Different PMQR genes may be located on different movable plasmids. By comparing the phenotypic changes of donor and receptor bacteria before and after conjugation, especially the change of detection rate of PMQR gene, it can be preliminarily determined. Transportable plasmids play an important role in the transmission of Escherichia coli resistance level.
【作者单位】：东北农业大学动物医学学院;
【基金】：哈尔滨市科技局科技创新人才基金(2013RFXXJ035)
【分类号】：S852.612
【正文快照】： 随着畜牧养殖业的迅速发展,各种抗生素和化学抗菌剂也不断得到开发利用,在其为人类做出突出贡献的同时,细菌耐药性现象也越发严重,尤其是R质粒的发现,证实了在遗传物质含有天然耐药基因的同时,细菌迫于生存压力,也可产生获得性耐药性[1],这就造成了耐药性不仅可以垂直传播,也

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