摘要
为了解奶牛乳房炎大肠埃希氏菌耐药性、毒力基因携带及分布情况,从2019年9月至2020年6月在新疆乌鲁木齐、伊犁、昌吉地区的7个奶牛场共采集了142份乳房炎奶牛牛乳样本,采用麦康凯培养基和伊红美蓝培养基进行筛选,利用生化试验和16S rDNA PCR方法鉴定出大肠埃希氏菌,用K-B纸片扩散法对分离株进行耐药性检测,PCR法检测其9种毒力基因,小鼠攻毒试验检测其致病性。结果显示,从142份样本中共分离出48株大肠埃希氏菌,分离率为33.8%(48/142);大肠埃希氏菌分离株对13种抗菌药物均具有不同程度的耐药性,对青霉素G的耐药率高达85.4%,克林霉素、阿莫西林、氨苄西林、头孢唑啉的耐药率在40%以上;48株分离菌中有35株检测到毒力基因,总检出率为72.92%(35/48),毒力基因iucD、FyuA、irp2、astA、escV、eaeA和ler检出率分别为35.41%、16.7%、16.7%、16.7%、4.17%、4.17%和4.17%;48株大肠埃希氏菌感染小鼠后死亡率为60%~100%。综上所述,新疆部分地区奶牛乳房炎大肠埃希氏菌携带iucD、FyuA、irp2、astA、escV、eaeA、ler等毒力基因,具有较强的致病性和多重耐药性。
In order to study the drug resistance,virulence genes and their distribution of Escherichia coli isolated from cow mastitis,142 samples of mastitis were collected from 7 dairy farms in Urumqi,Yili and Changji regions of Xinjiang from September 2019 to June 2020.MacConkey medium and eosin methylene blue medium were used for screening,and then Escherichia coli was identified by biochemical test and 16S rDNA PCR.For the isolated strains,K-B disk diffusion method was used to detect drug resistance,PCR method was used to detect 9 virulence genes,and mouse challenge test was used to detect pathogenicity.The results showed that 48 strains of Escherichia coli were isolated from 142 mastitis samples,and the isolation rate was 33.8%(48/142).The Escherichia coli isolates had varying degrees of resistance to 13 kinds of antibacterial drugs.The resistance rate of penicillin G was the highest and it achieved 85.4%,and the drug resistance rates of clindamycin,amoxicillin,ampicillin and cefazolin were above 40%.Virulence genes were detected in 35 out of 48 isolates,with a total detection rate of 72.92%(35/48).The detection rates of virulence genes iucD,FyuA,irp2,astA,escV,eaeA and ler were 35.41%,16.7%,16.7%,16.7%,4.17%,4.17%and 4.17%,respectively.The mortality of mice infected with all isolates was 60%-100%.In conclusion,Escherichia coli isolated from cow mastitis in some areas of Xinjiang carries virulence genes such as iucD,FyuA,irp2,astA,escV,eaeA and ler,which has strong pathogenicity and multiple drug resistance.
作者
刘肖利
刘璐瑶
李镔罡
李斌
裴文刚
程彪
苏战强
李勤凡
LIU Xiao-li;LIU Lu-yao;LI Bin-gang;LI Bin;PEI Wen-gang;CHENG Biao;SU Zhan-qiang;LI Qin-fan(College of Veterinary Medicine,Xinjiang Agricultural University,Urumqi,Xinjiang,830052,China;College of Veterinary Medicine,Northwest A&F Universiry,Yangling,Shaanxi,712100,China)
出处
《动物医学进展》
北大核心
2022年第1期46-51,共6页
Progress In Veterinary Medicine
基金
2019年新疆农业大学-中国农业大学联合基金项目(2019-7)
奶牛养殖提质增效关键技术集成示范项目(2020A01001-2)
新疆褐牛健康养殖技术集成与产业化示范项目(2017B01001-2)。
关键词
奶牛乳房炎
大肠埃希氏菌
耐药性
毒力基因
Cow mastitis
Escherichia coli
antimicrobial resistance
virulence gene
