大肠杆菌O157∶H7对氟苯尼考耐药机制的初步研究

发布时间：2018-04-03 14:26

  本文选题：大肠杆菌O∶H　切入点：氟苯尼考　出处：《中国人兽共患病学报》2016年03期

【摘要】：目的研究大肠杆菌O157∶H7(E.coli O157∶H7)对氟苯尼考耐药性产生的机制。方法本研究采用亚抑菌浓度体外耐药诱导的方法将E.coli O157∶H7诱导成为氟苯尼考高度耐药菌株,采用无抗生素压力下连续传代培养或SDS方法将耐药菌株的氟苯尼考耐药性消除,使用PCR方法检测氟苯尼考耐药基因floR,通过外排泵抑制剂与氟苯尼考联合使用,检测E.coli O157∶H7是否存在对氟苯尼考的主动外排作用。结果经过36代的耐药诱导,敏感菌株对氟苯尼考产生了高度耐药(MIC为256μg/mL)。质粒检测结果显示,耐药诱导菌株出现2个质粒,大小分别约为3 500bp和1 200bp,floR基因位于质粒DNA中。经连续传代培养或SDS法进行耐药消除,耐药诱导菌株对氟苯尼考的敏感性提高,但其质粒和floR基因均未丢失。结论 E.coli O157∶H7氟苯尼考敏感菌和耐药菌均存在对氟苯尼考的质子驱动型外排泵和ATP水解依赖型外排泵主动外排作用。
[Abstract]:Objective to study the mechanism of drug resistance of Escherichia coli O157:H7(E.coli O 157: h 7 to florfenicol.Methods in this study, E.coli O157:H7 was induced into florfenicol high resistance strain by subinhibitory concentration in vitro. The drug resistance of florfenicol resistant strains was eliminated by continuous passage culture without antibiotic pressure or by SDS method.Florfenicol resistance gene flor was detected by PCR method. The efflux pump inhibitor combined with florfenicol was used to detect whether E.coli O157:H7 had active efflux effect on florfenicol.Results after 36 generations of drug resistance induction, the sensitive strain produced high resistance to florfenicol with a MIC of 256 渭 g / mL 路L ~ (-1).The results of plasmid detection showed that two plasmids, about 3 500bp and 1 200 BP flor gene, were found in plasmid DNA.The sensitivity of the drug-resistance induced strains to florfenicol was improved by continuous passage culture or SDS method, but neither the plasmid nor the floR gene was lost.Conclusion both E.coli O157:H7 florfenicol sensitive bacteria and drug resistant bacteria have proton driven efflux pump and ATP hydrolytic dependent efflux pump active efflux.
【作者单位】： 广西大学动物科学技术学院;广西兽医研究所;广西畜禽疫苗新技术重点实验室;
【基金】：广西科技重大专项(桂科重14121003-4-1) 广西自然科学基金(桂科自2013GXNSFAA019093) 广西水产畜牧兽医局科研专项(桂渔牧科201528005)~~
【分类号】：R378
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本文编号：1705587