Validation of Droplet Digital Polymerase Chain Reaction for Salmonella spp. Quantification

Front Microbiol. 2020 Jul 7:11:1512. doi: 10.3389/fmicb.2020.01512. eCollection 2020.

Abstract

Salmonellosis is a foodborne disease caused by Salmonella spp. Although cell culture is the gold standard for its identification, validated molecular methods are becoming an alternative, because of their rapidity, selectivity, and specificity. A simplex and duplex droplet digital polymerase chain reaction (ddPCR)-based method for the identification and quantification of Salmonella using ttr, invA, hilA, spaQ, and siiA gene sequences was validated. The method has high specificity, working interval between 8 and 8,000 cp/μL in ddPCR reaction, a limit of detection of 0.5 copies/μL, and precision ranging between 5 and 10% measured as a repeatability standard deviation. The relative standard measurement uncertainty was between 2 and 12%. This tool will improve food safety in national consumption products and will increase the competitiveness in agricultural product trade.

Keywords: Salmonella; bioanalysis; droplet digital PCR; food safety; validation.