Evaluation of a Loop-Mediated Isothermal Amplification (LAMP) Method for the Detection of Salmonella spp. in Terms of Sensitivity and Applicability

Abstract

Salmonella spp. are important food-borne pathogens that can cause diseases in humans. Many detection methods have been established in Salmonella spp. using loop-mediated isothermal amplification (LAMP) or reverse transcription loop-mediated isothermal amplification (RT-LAMP). The detection limits of these assays varied from 1 CFU/reaction to 104 CFU/reaction, from 100 fg genomic DNA/reaction to 10 pg genomic DNA/reaction, or from 2.0×101 CFU/mL to 107 CFU/mL for food samples. In this study, LAMP assays were developed using genomic DNA for the detection of Salmonella spp. Two sets of LAMP primers were designed using the invA gene and the 16S-23S rRNA intergenic spacer region (ITS) of S. enterica as the target sequences for two LAMP assays. The detection limits of the two methods were respectively 20 pg S. enterica DNA/reaction and 10 pg S. enterica DNA/reaction at the optimized temperature, and the LAMP methods were of high repeatability and specificity for S. enterica detection. This study provides a baseline for the application of LAMP for the detection of food-borne pathogenic bacteria.