Evaluation of applied biosystems MicroSEQReg.-real-time PCR system for detection of Listeria spp. in food and environmental samples.

摘要

A complete system for real-time PCR detection of Listeria spp. was validated in 5 food matrices and 5 environmental surfaces, namely, hot dogs, roast beef, lox (smoked salmon), pasteurized whole cows' milk, dry infant formula, stainless steel, plastic cutting boards, ceramic tiles, rubber sheets and sealed concrete. The system consists of the MicroSEQReg.Listeria spp. Detection Kit, 2 sample preparation kits (PrepSEQReg. Nucleic Acid Extraction Kit and PrepSEQ Rapid Spin Sample Preparation Kit), the Applied Biosystems 7500 Fast Real-Time PCR instrument, and the RapidFinderTM Express v1.1 Software for data analysis. The test method was compared to the ISO 11290-1 reference method using an unpaired study design. The MicroSEQ Listeria spp. Detection Kit and the ISO 11290-1 reference method showed equivalent detection based on Chi-square analysis for all matrixes except hot dogs. For hot dogs, the MicroSEQ method detected more positives than the reference method for the low- and high-level inoculations, with all of the presumptive positives confirmed by the reference method. An independent validation study confirmed these findings on lox and stainless steel surface. The MicroSEQ kit detected all 50 Listeria strains tested and none of the 31 nontarget bacteria strains.