生牛奶中分离大肠杆菌对季铵盐类消毒剂耐药性研究  

Research on Quaternary Ammonium Compounds Disinfectant-Resistance of Escherichia coli in Raw Milk

作　　者：郭莉娟 孙丰慧[1,2] 张艳娇 刘海锋 廖小微 代敏[1,2] GUO Lijuan;SUN Fenghui;ZHANG Yanjiao;LIU Haifeng;LIAO Xiaowei;DAI Min(School of Laboratory Medicine,Chengdu Medical College,Chengdu 610500,China;Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-Origin Food,Chengdu Medical College,Chengdu 610500,China)

机构地区：[1]成都医学院检验医学院,成都610500 [2]成都医学院,四川省动物源性兽药残留防控工程实验室,成都610500

出　　处：《四川动物》2019年第6期623-629,645,共8页Sichuan Journal of Zoology

基　　金：国家自然科学基金面上项目(No.31970137);四川省科技厅苗子工程项目(No.2018085);成都市科技局惠民工程项目(No.2016-HM01-00362-SF);教育部春晖计划(No.Z2016120)

摘　　要：目的为调查牛奶中大肠杆菌Escherichia coli的污染状况和对常见季铵盐类消毒剂的耐药情况,为大型养殖场季铵盐类消毒剂的合理使用提供指导。方法对从74份生牛奶样品中分离的45株大肠杆菌采用琼脂稀释法测定4种季铵盐类消毒剂[十六烷基三甲基溴化铵(CTAB)、苯扎氯铵(BC)、双十烷基二甲基氯化铵(DDAC)、氯代十六烷基吡啶(CPC)]的最小抑菌浓度(MIC),采用PCR法检测10种消毒剂耐药基因,并分析其MIC值与耐药基因之间的相关性。结果大肠杆菌对4种消毒剂表现出不同程度的抗性,所检测的4种消毒剂对大肠杆菌的MIC值均大于标准菌株,且比例为BC=DDAC>CTAB>CPC。大肠杆菌季铵盐类消毒剂的耐药基因检出率为ydgF(84.44%)>ydgE(80.00%)>sugE(c)(66.67%)>emrE(40.00%)>mdfA(37.78%)>qacEΔ1(33.33%)>qacE(17.78%)>qacF(13.33%)>qacG(11.11%)>sugE(p)(4.44%)。分析大肠杆菌消毒剂基因检出情况与MIC值之间的关系发现,qacF基因的检出率与128 mg·L-1的CPC之间差异有统计学意义。结论由此可见,牛奶中存在大肠杆菌污染严重的现象对季铵盐类消毒剂耐药情况不容乐观,需进一步规范季铵盐类消毒剂的使用。Objective To investigate the contamination status of Escherichia coli in raw milk and their resistance to common quaternary ammonium compounds(QACs) disinfectants.Methods The minimal inhibitory concentration(MIC) values of 4 QACs disinfectants(cetyltrimethyl ammonium bromide, CTAB;benzalkonium chloride, BC;didecyldimethyl ammonium chloride, DDAC;cetyl pyridine chloride, CPC) for 45 E. coli isolates from raw milk were determined by agar dilution method, and 10 resistance genes were detected by PCR. The correlation between MIC values and resistance genes was analyzed also.Results E. coli showed different degrees of resistance to the 4 disinfectants. The MIC values of the 4 disinfectants tested against E. coli were larger than the standard strain, and the ratio was BC=DDAC>CTAB>CPC. The detection rate of resistance genes to QACs disinfectants was 4.44%-84.44%: ydgF(84.44%)>ydgE(80.00%)>sugE(c)(66.67%)>emrE(40.00%)>mdfA(37.78%)>qacEΔ1(33.33%)>qacE(17.78%)>qacF(13.33%)>qacG(11.11%)>sugE(p)(4.44%). There is a significant difference between the detection rate of qacF gene and CPC of 128 mg·L-1 concentration.Conclusion E. coli with more anti-disinfectant gene combinations and higher MIC values are prevalent in the milk from the tested farm. Therefore, the resistance of E. coli to disinfectants should be taken seriously.

关 键 词：大肠杆菌 季铵盐类 消毒剂 耐药性 

分 类 号：Q939.9[生物学—微生物学]