腹泻犬粪源大肠埃希氏菌的分离鉴定及其耐药特性与毒力基因的检测

Isolation,Identification,Drug Resistance Characteristics and Virulence Gene Detection of Escherichia coli from Feces of Diarrhea Dogs

为检测蚌埠地区腹泻犬肠道大肠埃希氏菌的耐药特性和毒力基因携带情况,采集75份腹泻犬粪便样本进行大肠埃希氏菌的分离鉴定,采用Kirby-Bauer(K-B)纸片扩散法对12种抗菌药物的耐药性进行检测,通过PCR对6种耐药基因及6种毒力基因进行检测。结果共分离得到62(82.7%,62/75)株大肠埃希氏菌,分离菌株对恩诺沙星耐药率为46.8%,对氨基糖苷类耐药率为9.7%~16.1%,其中丁胺卡那霉素为16.1%;头孢菌素类为6.5%~12.9%,其中头孢他啶为12.9%;喹诺酮类耐药基因qnr检出率为51.6%,头孢菌素类耐药基因blaCMY-2为9.7%;毒力基因mdh、fimC、ompA的检出率分别为100%、64.5%和74.2%。结果表明所分离大肠埃希氏菌对不同抗菌药物的耐药差异较大,耐药基因的分布与耐药表型有较高的相关性,mdh、fimC和ompA为主要携带毒力基因。临床上应加强对细菌抗菌药物耐受和毒力变化的监测,以提高治疗效果,减少耐药菌株出现。

In order to detect the drug resistance characteristics and virulence genes of Escherichia coli in the intestinal tract of diarrhea dogs in Bengbu area,75 fecal samples of diarrhea dogs were collected for the isolation and identification of Escherichia coli.The resistance of 12 antimicrobials was detected by Kirby-Bauer(K-B)disk diffusion method,and 6 drug resistance genes and 6 virulence genes were detected by PCR method.A total of 62(82.7%,62/75)Escherichia coli strains were isolated.The resistance rate to enrofloxacin was 46.8%,aminoglycosides 9.7%-16.1%,of which amikacin was 16.1%.Cephalosporin 6.5%-12.9%,of which ceftazidime was 12.9%.The detection rate of quinolone resistance gene qnr was 51.6%,and that of cephalosporin resistance gene blaCMY-2 was 9.7%;The detection rates of virulence genes mdh,fimC,and ompA were 100%,64.5%,and 74.2%,respectively.This study shows that the resistance of the isolated Escherichia coli to different drugs varies greatly,and the distribution of resistance genes is highly correlated with the resistance phenotype.mdh,fimC,and ompA are the main virulence genes.In clinical practice,monitoring of bacterial drug resistance and changes in virulence should be strengthened to improve treatment effectiveness and reduce the occurrence of drug-resistant strains.