Development of an SD-PMA-mPCR assay with internal amplification control for rapid and sensitive detection of viable Salmonella spp., Shigella spp. and Staphylococcus aureus in food products. (November 2015)

• Record Type: Journal Article
• Authors: Wang, Lijun; Ye, Chenlian; Xu, Hengyi; Aguilar, Zoraida P.; Xiong, Yonghua; Lai, Weihua; Wei, Hua
• Is Part Of: Food control. Volume 57(2015:Nov.)
• Page Start: 314
• Page End: 320
• Publication Date: 2015-11
• Subjects: Foodborne pathogens -- SD-PMA-mPCR -- IAC -- Detection; Food -- Quality -- Periodicals; Food -- Analysis -- Periodicals; Food handling -- Periodicals; Food industry and trade -- Quality control -- Periodicals; Aliments -- Industrie et commerce -- Qualité -- Contrôle -- Périodiques; Aliments -- Qualité -- Périodiques; Aliments -- Analyse -- Périodiques; Hygiène alimentaire -- Périodiques; Food -- Analysis; Food handling; Food -- Quality; Periodicals; Electronic journals; 664.07
• DOI: 10.1016/j.foodcont.2015.04.016
• Languages: English
• ISSNs: 0956-7135

Abstract

Abstract: In this work, a specific, sensitive, and accurate technique was presented for simultaneous detection of Salmonella spp., Shigella spp., and Staphylococcus aureus in food products, three of the more frequent foodborne pathogens that were usually reported in a variety of food matrices. An internal amplification control (IAC) was added in a multiplex PCR (mPCR) reaction system as an indicator of false negative result that can come from the presence of PCR inhibitors in food products. In the presence of inhibitor, no signal would result for the target genes as well as the IAC which results in a positive signal, thereby, eliminating false negative results. To ensure detection of only the viable cells, the effects of sodium deoxycholate (SD) in combination with propidium monoazide (PMA) treatment in the presence of dead cells and viable cells were investigated. Results showed that PMA treatment alone could not effectively inhibit the detection of 10 7 CFU/mL of dead Salmonella Typhimurium, Shigella sonnei, and S. aureus from PCR amplification. However, the SD in combination with PMA treatment gave negative results for PCR amplification of dead S. Typhimurium, S. sonnei, and S. aureus in pure culture and food products. When the developed SD-PMA-mPCR assay in combination with IAC was applied to detect the spiked food (milk, ground beef), the LOD of SD-PMA-mPCR assay for S. Typhimurium, S. sonnei, and S. aureus inoculated individually or inoculated simultaneously into milk or ground beef were 10 1 CFU/mL or 10 1 CFU/g after 15 h enrichment. The results suggested that the SD-PMA-mPCR assay in combination with IAC held promise for the detection of foodborne S. Typhimurium, S. sonnei, and S. aureus. Highlights: A novel mPCR assay was developed for detecting viable Salmonella spp., Shigella spp., and Staphylococcus aureus. The SD in combination with PMA was used to exclude the interference from 10 7 CFU/mL injured and dead cells. An IAC was included to indicate the false negative results. With 15 h enrichment, 10 1 CFU/mL (CFU/g) viable cells in milk or ground beef could be detected.