《中国畜牧兽医》 ›› 2019, Vol. 46 ›› Issue (5): 1499-1507.doi: 10.16431/j.cnki.1671-7236.2019.05.029

• 基础兽医 • 上一篇    下一篇

内江市猪源大肠埃希菌抗菌药与消毒剂交叉耐药性研究

杨文1, 陈红伟2, 曾杨梅3, 吴俊伟2   

  1. 1. 内江职业技术学院, 内江 641100;
    2. 西南大学动物科学学院, 荣昌 402460;
    3. 重庆布尔动物药业有限公司, 荣昌 402460
  • 收稿日期:2018-11-16 出版日期:2019-05-20 发布日期:2019-05-20
  • 通讯作者: 吴俊伟 E-mail:wjw999@163.com
  • 作者简介:杨文(1967-),男,四川内江人,学士,副教授,研究方向:兽医药理学与毒理学,E-mail:445937759@qq.com
  • 基金资助:

    国家自然科学基金"acrAB-tolC基因在大肠埃希菌对消毒剂苯扎溴铵和四环素类抗菌药物交叉耐药机制中的作用研究"(31372483);重庆市基础科学与前沿技术研究项目"粉防己甲素逆转细菌外排泵AcrAB-TolC外排耐药的分子机制初步研究"(cstc2017jcyjA0416)

Cross-resistance of Antimicrobials and Disinfectants of Escherichia coli from Neijiang City

YANG Wen1, CHEN Hongwei2, ZENG Yangmei3, WU Junwei2   

  1. 1. Neijiang Vocational & Technical College, Neijiang 641100, China;
    2. College of Animal Science, Southwest University, Rongchang 402460, China;
    3. Chongqing Bull Animal Pharmaceutical Company, Ltd., Rongchang 402460, China
  • Received:2018-11-16 Online:2019-05-20 Published:2019-05-20

摘要:

为了解内江市猪源大肠埃希菌对抗菌药与消毒剂的交叉耐药情况及交叉耐药机制。本试验以大肠埃希菌标准菌株(ATCC 25922)为质控菌,检测从内江市分离的66株猪源大肠埃希菌的耐药性,采用微量肉汤稀释法测定常用抗菌药恩诺沙星、土霉素和消毒剂苯扎溴铵、戊二醛对受试菌株的最小抑菌浓度(MIC),进行耐药性检测,并筛选出对抗菌药和消毒剂均耐药的交叉耐药菌;PCR扩增标准菌株和交叉耐药菌的qacE△1、acrA、acrBtolC基因,采用琼脂糖凝胶电泳检测基因携带和扩增情况,并对acrA、acrBtolC基因进行测序,以标准菌株的acrA、acrBtolC基因为参照,比对交叉耐药菌相应基因突变情况。结果显示,从内江市分离的66株猪源大肠埃希菌对恩诺沙星和土霉素完全耐药,对苯扎溴铵耐药的有3株,而所有菌株均对戊二醛敏感,即对抗菌药和消毒剂均耐药的交叉耐药菌有3株,编号分别为5、6、7号。在检测的3株交叉耐药菌中,仅6号菌检出qacE△1基因;基因序列比对结果显示,与标准菌株相比,交叉耐药菌的acrA、acrBtolC基因碱基和氨基酸均有突变发生,碱基突变率最高的是7号菌的tolC基因(2.10%),突变率最低的是7号菌的acrA基因(0.97%);氨基酸突变率最高的为7号菌的acrB基因(2.39%),突变率最低的是tolC基因,且3株菌突变率相同(均为0.22%);3个基因有部分碱基或氨基酸有一致突变。所检测的内江市猪源大肠埃希菌对常用抗菌药恩诺沙星和土霉素耐药性严重,已有对抗菌药和消毒剂交叉耐药的菌株,且其交叉耐药的机制与外排泵AcrAB-TolC有相关性。

关键词: 大肠埃希菌; 消毒剂; 抗菌药; 交叉耐药性

Abstract:

This study was aimed to understand the degree and mechanism of cross resistance of Escherichia coli isolated from some pig farms in Neijiang city to antimicrobials and disinfectants.The minimal inhibitory concentration (MIC) values for enrofloxacin,oxytetracycline,benzalkonium bromide and glutaraldehyde of 66 strains of Escherichia coli isolated from some pig farms in Neijiang city were determined using broth microdilution method and selected cross resistance strains that were resistant to antimicrobials and disinfectants.Whether the cross resistance strains had qacE△1,acrA,acrB and tolC genes was detected by PCR technology and agarose gel electrophoresis.And the mutation of acrA,acrB and tolC genes of these strains were determined.All the 66 strains were resistant to enrofloxacin and oxytetracycline,and three strains (named as No.5,No.6 and No.7) were resistant to benzalkonium bromide,but no strains were resistant to glutaraldehyde.It showed that there were three strains were cross resistance strains.All the three cross resistance strains had acrA,acrB and tolC genes,but only No.6 had qacE△1 gene.All the genes acrA,acrB and tolC of the three strains occurred mutation,and the amino acid that transcribed by these genes also occurred mutation.The highest and lowest base mutation rate were 2.10% (No.7's tolC gene) and 0.97% (No.7's acrA gene).The highest and lowest amino acid mutation rate were 2.39% (No.7's acrB gene) and 0.22% (tolC gene of No.5,No.6 and No.7).And some mutation occurred at the same base site or the same amino acid site.All the 66 strains isolated from some pig farms in Neijiang city were resistant to enrofloxacin and oxytetracycline,and there were cross resistance strains that were resistant to antimicrobials and disinfectants,and the cross resistance mechanism of these strains might related to the efflux pumb AcrAB-TolC.

Key words: Escherichia coli, disinfectant, antimicrobials, cross resistance

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