Abstract: Objective: To develop a rapid and simple method for qualifying Listeria monocytogenes in foods using 1oop-mediated isothermal amplification (LAMP), and to preliminarily develop a fluorescent quantitative method for the determination of this bacteria spices based on LAMP. Methods: According to the principle of LAMP, primers were designed for the development of measurement methods for Listeria monocytogenes. Meanwhile, the specificity, sensitivity and repeatability of the developed method were assessed, and the linear relationship between the logarithmized number of initial copies and reaction time was examined. Results: The detection of Listeria monocytogenes with designed LAMP primers could be finished in 0.5 h. The developed detection technique showed a sensitivity over 100-fold higher than PCR, and the limit of detection was 1.72 × 101 copies per reaction. No cross-reactivity with other foodborne pathogens was observed. Avery intra-test coefficients of variation at five gradient levels of concentration were all smaller than 5%. There was an excellent linear relationship between reaction time and initial template concentration found, with a determination coefficient R2 equaling 0.9994. Conclusion: This method is characterized by rapidity, high sensitivity and specificity, ease of operation, and low equipment requirements, with extensive application prospects.

Key words: Listeria monocytogenes, loop-mediated isothermal amplification (LAMP), rapid detection