中文摘要：

为了解宁夏地区奶牛乳房炎大肠杆菌耐药性及毒力基因、耐药基因的分布情况,采用K-B法测定从奶牛乳房炎病例分离的197株大肠杆菌对16种抗菌药物的敏感性,并采用PCR技术对大肠杆菌毒力基因及耐药基因进行检测。结果显示,大肠杆菌对氨苄西林的耐药率最高,达到54.69%,对多西环素、四环素和链霉素的耐药率在39%左右,而对头孢唑啉、头孢噻肟、多黏菌素、氟苯尼考和喹诺酮类药物则比较敏感,敏感率都在60%以上。基因检测结果显示,除sta、stx2e这2种毒力基因未被检测到,astA、escV、eaeA、sepA、hlyA5种毒力基因的检出率分别是20.30%、14.72%、8.12%、2.03%、1.02%。四环素类的2种耐药基因均被检测到,其中tetC的阳性率为24.87%。氟喹诺酮类的GyrA、GyrB、ParC三种耐药突变的检出率分别高达97.46%、98.98%、98.48%。宁夏地区奶牛乳房炎大肠杆菌携带astA、eaeA、sepA、escV、hlyA等毒力基因和介导四环素类、氟喹诺酮类耐药的基因,对16种抗菌药物具有不同程度的耐药性,且存在多重耐药菌株。

英文摘要：

The objectives of this study were to investigate resistance,virulence genes and resistance genes of Escherichia coli isolated from dairy cow mastitis in Ningxia.The antimicrobial resistance of 197 Escherichia coli from dairy cow mastitis cases to 16 drugs was determined by the methods of K-B and the virulence genes and resistance genes were detected by PCR.The results showed that the resistance rate of ampicillin was the highest and it achieved 54.69%.Furthermore,the resistance rates of doxycycline,tetracycline and streptomycin were about 39%.It was more sensitive to cephazolin,cefotaxime,polymyxin,florfenicol,quinolones,and the sensitive rates were above 60%.The results of genes detection showed that the detection rates of virulence genes astA,escV,eaeA,sepA,hlyA were 20.30%,14.72%,8.12%,2.03%and 1.02%respectively.The virulence genes staand stx2 e were not detected.Tetracycline resistant genes were detected and the detection rate of tetC was 24.87%.The detection rate of fluoroquinolone resistance genes GyrA,GyrB and ParC were 97.46%,98.98%and 98.48%,respectively.Our study demonstrates Esche-richia coli isolates from dairy cow mastitis in Ningxia carrying virulence genes astA,eaeA,sepA,escV,hlyAand the genes mediate resistance to tetracyclines,fluoroquinolones,and those isolates have varying degrees of resistance 16 kinds of antibacterial drugs,and some isolates are multi-resistant strains.