PCR快速检测食品中志贺氏菌方法的建立

目的本研究根据福氏志贺菌(Shigella lexneri)侵袭性质粒抗原H基因(invasion plasmid antigen H,ipaH),设计了一对特异性引物,预计PCR扩增的目的基因片段为435bp。对PCR的特异性、敏感性分析以及建立L16(43)正交试验对PCR扩增条件如引物浓度、dNTP浓度和Tm值等的优化,建立了快速检测福氏志贺菌的稳定的PCR方法。该方法检测的灵敏度为可以检测到食品中7 ng/ml福氏志贺菌的基因组DNA。并且模拟检测食品中的细菌,结果很稳定。该方法操作简单、检验周期短、特异性和灵敏度高,能够快速地实现对食品中的志贺菌的诊检和监控。

A rapid PCR assay for the detection of Shigella flexneri in food samples

According to the invasive plasmid antigen H gene(ipaH)of Shigella flexneri,one pair of primers was designed,and the anticipated target fragment of PCR product was assumed to be 435 bps.The conditions for specificity and sensitivity analysis of PCR for single gene and the condition for optimization reaction by orthogonal experiment design L16(43),such as concentration of primers and dNTP and the Tm value were optimized.In this way,a rapid and stable method of PCR assay for the detection of S.flexneri was established.The sensitivity of this method was found to be 7 ng/ml genomic DNA of S flexneri in food samples.In addition,bacteria could be detected in the mimic samples of food with the stable results.This method of PCR assay appears to be simple,rapid,highly sensitive and specific,and quite valuable for the detection and surveillance of S.flexneri infection.