摘要
大肠杆菌mgrB变异和携带mcr基因是其对多黏菌素耐药的重要机制,威胁着多黏菌素的临床应用。为了比较mgrB和mcr在猪源大肠杆菌中对多黏菌素耐药的影响,本试验收集165株猪源大肠杆菌,采用微量肉汤稀释法测定菌株对多黏菌素敏感性,并对耐药菌的mcr-1~mcr-5以及mgrB进行检测及测序比对分析。结果显示,165株猪大肠杆菌中有147株对多黏菌素耐药(MIC≥4 mg/L),耐药率为89.1%(147/165),147株耐药菌中均未检出mcr-2~mcr-5基因,且仅有1株(EPF25)不含mcr基因。mgrB基因经PCR检测并测序比对后发现mgrB启动子区变异的有104株菌,mgrB编码区氨基酸变异的有11株,在147株耐药菌中占78.2%(115/147)。结果表明比较多黏菌素对受试菌的MIC值及耐药菌mcr-1、mgrB基因变异之间的关系发现相关性不明显,猪大肠杆菌对多黏菌素耐药是mcr基因和mgrB变异共同作用的结果。
The important mechanisms of colistin resistance in Escherichia coli(E.coli) are mgrB mutions and harboring mcr genes, which threats to the clinical use of colistin.The effects of mgrB and mcr on colistin resistance in E.coli was compared to explore their contribution to colistin resistance in clinical strains.In this study, a total of 165 E.coli isolates from swine were collected.Colistin minimum inhibitory concentrations were determined by the broth microdilution method.PCR for the mcr-1 to mcr-5 genes was performed on colistin resistance E.coli.Mutations in the mgrB gene and mgrB-promoter regions were analysed.The results showed that among the 165 strains of E.coli,147 isolates showed resistance to colistin(MIC≥4 mg/L) with a resistance rate of 89.1%(147/165).Meanwhile, there were not colistin-resistant strains harboring mcr-2 to mcr-5 genes, and only one of them(EPF25) did not contain mcr gene.A total of 115 strains of E.coli were mutated in mgrB gene, 104 strains were found to have base mutations in mgrB-promoter regions, and 11 strains were found to have amino acid mutations in the coding region of mgrB.There was not significant correlation between the MICs of colistin and resistance mechanisms.The resistance of E.coli to colistin is the combinational effect of mcr gene and mgrB mutations.
作者
邝启红
李文娅
李垠树
贾雅婷
胡功政
苑丽
KUANG Qihong;LI Wenya;LI Yinshu;JIA Yating;HU Gongzheng;YUAN Li(College of Veterinary Medicine,Henan Agricultural University,Zhengzhou 450046,China)
出处
《中国兽医学报》
CAS
CSCD
北大核心
2021年第3期487-492,共6页
Chinese Journal of Veterinary Science
基金
国家自然科学基金资助项目(31772800)。
