Evaluation of Loop Mediated Isothermal DNA Aplification (LAMP) Detection of Salmonella spp. in Foods and Listeria monocytogenes on Environmental Surfaces

Abstract

Salmonella spp. and Listeria monocytogenes are listed in top five pathogens contributing to domestically acquired foodborne illnesses resulting in death according to Centre for Disease Control (CDC). A novel detection method combining loop mediated isothermal DNA amplification (LAMP) method with bioluminescence named as 3M? molecular detection system (MDS) has recently been developed. 3M? molecular detection assay (MDA) is used with the 3M? MDS for qualitative analysis of pathogens in foods and environmental samples the next day after enrichment.. For the first study, a healthy and injured Salmonella cocktail was inoculated on raw duck wings, raw bean sprouts and processed fish balls to achieve two inoculation levels: 10^0 and 10^1 CFU/25g respectively. Validation on the naturally contaminated food matrices was conducted as well. The second study was the detection of L. monocytogenes on environmental surfaces at 3 inoculum levels: 10^0, 10^1 and 10^2 CFU/100 cm2. Often, food preparation surfaces are contaminated with food, hence it is of interest to determine whether the presence of organic load affects the viability of Listeria monocytogenes on stainless steel (SS) and polyethylene (PE) surfaces.