鸡源致病性大肠杆菌对四环素类抗生素耐药性及耐药基因检测

为更好地了解鸡源致病性大肠杆菌对四环素类抗生素的耐药性及耐药基因分布,从陕西省部分规模化养鸡场的病、死鸡中经分离鉴定得到158株致病性大肠杆菌。采用K-B药敏纸片法检测致病性大肠杆菌分离株对4种四环素类药物的药敏性,PCR方法检测3种四环素类耐药基因,用DNAStar软件对获得的耐药基因序列与GenBank中的相关序列进行比对。结果显示,鸡源致病性E.coli分离株对四环素、金霉素、土霉素以及多西环素的耐药率分别为88.6%、77.2%、87.3%、50.6%,3重以上耐药菌株占78.5%。四环素类耐药基因tetA、tetB的检出率分别为81.4%、20.7%,未检测到tetC基因。结果表明,鸡源致病性E.coli对四环素类抗生素普遍具有耐药性,且以多重耐药为主;耐药基因tetA的检出率与其耐药性呈正相关。

The Resistance of Pathogenic Escherichia coli Isolates from Chickens to Tetracycline Antibiotics and the Detection of Resistance Genes

In order to understand the resistance of pathogenic Escherichia coli isolates from chickens to tetracycline antibiotics and distribution of resistant genes, 158 strains pathogenic E.coli were isolated and identified from the dead chickens in parts scale farm of Shaanxi provinces. The susceptibility of pathogenic E.coli isolates to four kinds of tetracyclinesantibiotics were detected by the Kirby-Bauer disk method, three kinds of tetracycline''s resistance genes were detected by the PCR method, compare the resistance gene sequences with the related sequences in GenBank by the DNAStar software. The results show that the resistance rates of pathogenic E.coli isolates from chickens to tetracycline, chlortetracycline, oxytetracycline and doxycycline were 88.6%, 77.2%, 87.3%, and 50.6%,respectively. More than 30% resistant strains accounted for 78.5%. The detection rate of tetracycline resistance gene tetA, tetB were 81.4% and 20.7%,respectively.tetC genes was not detected. The results showed that the resistance of pathogenic E.coli isolates from chickens to tetracycline antibiotics was widespread exist and most were multi-drug resistant; the detection rate of resistance genes tetA was positively correlated with their resistance.