Loop-Mediated Isothermal Amplification for Detecting Four Major Foodborne Pathogens in Meat and Meat Products

Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Escherichia coli O157:H7 are four major foodborne pathogenic bacteria found in meat and meat products, which pose significant threats to human health. In this study, we developed specific loop-mediated isothermal amplification (LAMP) primers targeting these four pathogenic bacteria. Following the optimization of system components and reaction parameters, four rapid and simplified LAMP-based detection assays were established, which enabled the visual detection of these four pathogenic bacteria within 40-50 min. The three established LAMP assays targeting L. monocytogenes, S. aureus, and E. coli O157:H7 achieved species-level discrimination, whereas the LAMP method for Salmonella exhibited genus-level specificity. The detection limits of the LAMP assays were determined as follows: 1.8 × 10¹ colony forming units (CFU)/mL for L. monocytogenes, 5.1 × 10¹ CFU/mL for S. aureus, 1.2 × 10¹ CFU/mL for S. enterica, and 3.3 × 10³ CFU/mL for E. coli O157:H7, with sensitivity improved by 10-1000-fold compared to conventional PCR. The developed LAMP assays were used to analyze 52 meat and meat product samples, and 7 samples were positive, which was consistent with the results of the conventional PCR and culture-based methods, demonstrating an accuracy rate of 100% for the LAMP methods. In conclusion, the established LAMP assays exhibit high specificity, enhanced sensitivity, and result visualization, making them suitable for on-site rapid detection in food safety monitoring.