Abstract:

An assay of PCR was developed for the detection of Salmonella in meat. Based on flotation and solvent extraction technology, FTA filter was used to extract Salmonella DNA from fresh meat to eliminate the inhibitory factors of PCR reaction. An invA gene in surface protein of epithelial cells absorbed and invaded by Salmonella was used to amplify a 376 bp DNA fragment, which could be confirmed by DNA sequencing. The detection limits of Salmonella in pork, beef, mutton and chicken homogenates all were 7×101 CFU/ml, and the detection could be finished in 6 h, which was shorter than that of the conventional method of combined enrichment and PCR by 12－24 h. In this study, 72 samples were detected and the results were compared with the GB/T 4789.4—2003 method. The detection rates of Salmonella by this method and the GB/T 4789.4—2003 method were 27.8% and 22.2%, and the detection by the latter method cost 5 days. In general, this method is a rapid and sensitive approach to the Salmonella detection in meat. Meanwhile, the DNA template preparation using FTA filter paper can constructs a technological platform for the fast detection of pathogens in food.

Key words: PCR, FTA filter paper, Salmonella, meat