Loop-mediated isothermal amplification (LAMP) coupled with bioluminescence for the detection of Listeria monocytogenes at low levels on food contact surfaces

A commercial loop-mediated isothermal amplification (LAMP) based system with bioluminescence, named as 3M (TM) Molecular Detection Assay (MDA), was validated for the detection of Listeria monocytogenes (3-strain cocktail) at low levels (10(0), 10(1), 10(2) CFU/100 cm(2)) inoculated on stainless steel (SS) and polyethylene (PE) surfaces, with and without (w/o) organic load (OL) of cold-smoked salmon homogenate by comparing with a standard ISO method as reference. The results of this study revealed that a commercial LAMP-based method performed equally effective compared with ISO method at inoculum levels of 10(0) and 10(2)/100 cm(2), showing 100% specificity and sensitivity, respectively. At 10(1) CFU/100 cm(2), a slight reduction in the effectiveness of LAMP-based method was observed most likely due to the use of single enrichment step in the procedure of LAMP-based method. The LAMP-based method was shown to be rapid and reliable detection technique for L. monocytogenes present at low numbers on food processing surfaces, regardless of organic residues, and can be applicable in seafood industry. (c) 2015 Elsevier Ltd. All rights reserved.