耐氟喹诺酮类药物禽源大肠埃希菌gyrA基因的检测分析

发布时间：2018-07-18 09:16

【摘要】：探讨不同禽源大肠埃希菌中喹诺酮类药物的耐药情况及耐药基因gyrA的分布和突变特征。采用K-B药敏纸片法、gyrA基因的PCR扩增,对9株大肠埃希菌进行喹诺酮类药物试验,并将gyrA基因的PCR产物测序,对测序结果采用DNA MAN、DNA Star、MEGA6等软件分析。药敏试验结果表明,C1、C2、C3菌株对左氧沙星、氧氟沙星、环丙沙星、诺氟沙星敏感,D1、D2、D3、B1、B2和B3菌株对左氧沙星、氧氟沙星、环丙沙星、诺氟沙星均表现为耐药和中介;gyrA基因的测序结果表明,除B1菌株有1处核苷酸突变位点和B2菌株有14处核苷酸突变位点;B2菌株gyrA基因的氨基酸突变发生在87位Ile→Val替代、101位Leu→Met替代、102位Ala→Ser替代、129位Lys→Gln替代。9株禽源大肠埃希菌的同源性和进化树分析表明,不同禽源耐氟喹诺酮类药物的大肠埃希菌菌株中B2菌株gyrA基因与其他9株菌株相比,同源性在90%左右,进化树不在一个分支上,研究中的B2菌株将为大肠埃希菌的氟喹诺酮类耐药机制的研究提供候选菌株。
[Abstract]:The drug resistance of quinolones in Escherichia coli from different avian sources and the distribution and mutation characteristics of the drug resistance gene gyrA were investigated. The K-B drug sensitive paper method and the PCR amplification of gyrA gene were used to test 9 strains of Escherichia coli, and the PCR products of the gyrA gene were sequenced, and the sequencing results were soft, DNA MAN, DNA Star, MEGA6 and so on. The results of drug sensitivity test showed that C1, C2, C3 strains were sensitive to levofloxacin, ofloxacin, ciprofloxacin, norfloxacin, D1, D2, D3, B1, B2 and B3 were resistant to levofloxacin, ofloxacin, ciprofloxacin and norfloxacin, and gyrA based sequences showed that there were 1 nucleotide mutation sites and B2 strains except B1 strains. There are 14 nucleotide mutation sites, and the amino acid mutation of the B2 strain gyrA gene occurs in 87 Ile to Val substitution, 101 Leu to Met substitution, 102 Ala to Ser substitution, and 129 Lys to Gln substitutes for.9 strain of avian Escherichia coli. Compared with the other 9 strains, the homology is about 90%, and the evolutionary tree is not on one branch. The B2 strain in the study will provide a candidate for the study of the fluoroquinolone resistance mechanism of Escherichia coli.
【作者单位】：湖北省农业科学院畜牧兽医研究所/农业部畜禽细菌病防治制剂创制重点实验室/动物胚胎工程及分子育种湖北省重点实验室;
【基金】：国家重点研发计划项目(2016YFD0501305,2016YFD0500800) 公益性行业(农业)科研专项项目(201303044) 现代农业产业技术体系建设专项资金项目(CARS-42-G11) 湖北省农业科学院青年科学基金项目(2016NKYJJ16)
【分类号】：S852.61

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