多重PCR技术检测沙门菌两种四环素耐药基因

应用两对特异性引物同时检测四环素耐药基因tetB和tetC通过对35株沙门菌分离株的四环素耐药性检测，表明所有沙门菌分离株均含tetC基因，与药敏试验结果阳性符合率65．7％，8株同时含有tetB基因，与药敏试验结果阳性符合率100％，tetB基因和tetC基因双阳性的菌株与药敏试验结果阳性符合率也为100％。取其中部分菌株扩增出tetB和tetC基因片段进行序列分析，5株菌的tetB基因扩增产物序列完全相同，与质粒pRT11相应序列同源性达99．7％；14株菌的tetC基因扩增产物与质粒pBR322中的相应序列同源性为100％。证实沙门菌耐药基因普遍存在，且同时含有tetB和tetC基因的菌株表现耐药。多重PCR技术同时检测两种四环素耐药基因，适合大量样本的检测，对开展沙门菌四环素多种耐药基因的分子流行病学监测提供了有效途径。

Detection of the resistance genes of tetracycline, tetB and tetC in Salmonella by multiplex polymerase chain reaction

A multiplex PCR method was developed to simultaneously amplify two tetracycline-resistance genes tetB and tetC. Among thirty-five Salmonella isolates, 100%tetC and 22.9%tetB positive results were obtained in this PCR assay by amplifying 418bp (tetC)and 659bp (tetB)PCR products. Compared with the results of the drug susceptibility test, those of PCR showed 65.7%concordance in positive rate and 100%concordance for Salmonella simultaneously containing tetB and tetC genes. The sequencing result showed tetB genes from five isolated Salmonella strains were 100%homology with each other and 99.7%homology with that from pRT11; tetC genes from fourteen isolated Salmonella strains were 100%homology with that from pBR322. The results showed that antibiotic resistance genes were commonly present in the isolated strains. The established multiplex PCR technique was simple, rapid, saving money and time and could be specially to detect a lot of samples.