羔羊大肠杆菌分离鉴定及其致病性、耐药表型和耐药基因检测

Isolation and identification,pathogenicity,drug resistance phenotype and drug resistance gene detection of Escherichia coli from lambs

目的:对皖北地区羊养殖场中所采集的37份腹泻羔羊粪便样本进行病原菌的分离鉴定,并对其耐药性及耐药基因进行测定。方法:将采集样本进行病原菌分离鉴定并进行同源性分析,通过药敏试验测定分离菌药物敏感性并对其耐药基因进行检测。结果:试验分离细菌37株,经生长特性、生化鉴定及16S rRNA测序对比序列确定分离菌均为大肠杆菌。致病性检测大肠杆菌中有21株为产志贺毒素大肠杆菌,其中S tx-1毒力基因和Stx-Ⅱ毒力基因分别占比8.10%和48.65%,肠毒性大肠埃希杆菌在本次试验中未检出。对分离的大肠杆菌进行耐药基因检测,6组耐药基因中tetA(97.30%)和qnr(83.78%)检出率较高。药敏结果显示分离的大肠杆菌对复方新诺明和林可霉素的耐药率分别达到89.19%和94.59%。结论:皖北地区部分大肠杆菌存在致泻性、携带多种耐药基因、存在多重耐药情况。

Objective:To isolate and identify the pathogenic bacteria from 37 fecal samples of diarrhea lambs collected from sheep farms in northern Anhui,and to determine their drug resistance and resistance genes.Methods:The collected samples were isolated,identified,and homologous analysis was performed.The drug sensitivity of the isolated bacteria was determined through drug sensitivity testing,and their drug resistance genes were detected.Results:37 strains of bacteria were isolated in the experiment.After growth characteristics,biochemical identification,and 16S rRNA sequencing and comparison,it was determined that the isolated bacteria were all Escherichia coli.In the pathogenicity test,21 strains of E.coli were Shiga toxin producing E.coli,of which the Stx-1 and Stx-II virulence genes accounted for 8.10%and 48.65%respectively.Enterotoxic E.coli was not detected in this test.The detection rates of tetA(97.30%)and qnr(75.68%)in the six groups of drug resistant genes in isolated E.coli were higher.The drug sensitivity results showed that the resistance rates of the isolated E.coli to cefotaxiphene and lincomycin were 86.49%and 94.59%,respectively.Conclusion:Some E.coli strains in Northern Anhui have diarrhea,carry multiple drug resistance genes,and have multiple drug resistance.