鸡源性沙门氏菌耐药基因检测与耐药相关性分析

Drug resistance gene detection and the resistance correlation analysis in Salmonella isolated from chickens

为研究沙门氏菌耐药基因与其耐药性之间的关系,本研究以K-B纸片法对临床分离的29株鸡源性沙门氏菌进行10种抗菌药物敏感性测定,应用PCR技术进行这些抗菌药物相关耐药基因检测。并通过质粒接合试验证明了耐药性及耐药基因的转移。结果显示:29株分离株对氨苄西林耐药率为31.0%,对头孢唑啉耐药率为10.3%,对四环素耐药率为44.8%,对复合磺胺耐药率为41.4%,对氯霉素耐药率为3.4%,对环丙沙星、氧氟沙星、诺氟沙星的耐药率均为37.9%,但对庆大霉素和卡那霉素均敏感。本实验共检测到8种耐药基因,其中blatem-1阳性率为31.0%,tetA和tetB阳性率为44.8%,sul1和sul2阳性率为41.3%,aadA1阳性率为3.4%,dfrA1阳性率为10.3%,qnr阳性率为37.9%,而tetG、blaCMY-2和catI均未检出。此外,通过与非耐药菌接合后绝大部分接合子均获得了供体菌质粒编码的相应抗性表型,耐药基因在接合过程也发生了转移,赋予被接合细菌新的耐药性。以上结果表明沙门氏菌的耐药性与其相关耐药基因的检出率基本一致,而且耐药性通过质粒进行转移。

To investigate the relationship between drug-resistant genes and drug resistance, a total of 29 Salmonella isolated from chickens to 10 antibacterial were tested by Kirby-Bauer method. The results showed that the resistance rates were 31%, 10.3%, 44.8%, 41.4%, 3.4% and 37.9% to the drugs of AMP, CFZ, TET, SXT, CMP, CIP, OFL and NOR, respectively, but still sensitive to GEN and KAN. In addition, the positive rates of the resistance genes of blatem-1, tetA, tetB, sull, sul2, aadA1, dfrA1 and qnr were 31.0%, 44.8%, 41.3%, 3.4%, 10.3% and 37.9%, respectively, among the isolates detected by PCR, while tetG, blaCMY-2 and catI were not detected. Moreover, a large proportion of zygotes acquired the corresponding resistance phenotype encoded by donor bacterial plasmid after conjugating with drug sensitive bacteria. These results suggested that the drug resistance rate of the Salmonella isolates and their drug resistance related genes was essential consistent and the drug resistance was transferred through plasmid born resistant gene.