Development of a Visual and Rapid Method Using Loop Mediated Isothermal Amplification in Conjunction With a Specific Molecular Beacon Probe for Salmonella Detection

Abstract

Background:Salmonella is a major global threat due to the associated widespread prevalence as a foodborne pathogen; thus, timely diagnostic methods to enable effective disease management are required. Loop-mediated isothermal amplification (LAMP), although renowned for its high sensitivity, specificity, and rapid analysis in foodborne pathogen detection, is frequently hampered by false-positive results due to primer dimer formation.Methods:This study introduced a specific molecular beacon (MB) probe to ensure high sequence specificity, and developed a novel MB-LAMP assay for rapid, visual detection of Salmonella. The performance of the assay was evaluated using Salmonella genomic DNA and artificially contaminated milk samples to assess the assess the analytical sensitivity and practical applicability of the assay in food matrices.Results:The MB-LAMP assay demonstrated high efficiency, completing the detection process in less than 50 min, the analytical sensitivity reached 1.11 pg/μL for Salmonella genomic DNA. In artificially contaminated milk samples, the method achieved a limit of detection (LOD) of 1000 Colony-Forming Units (CFU)/mL. Notably, the results were readily interpretable by visual inspection without the need for sophisticated instrumentation.Conclusion:This MB-LAMP assay provides a highly sensitive, robust, and decentralized molecular diagnostic tool. Indeed, by bypassing traditional cultivation steps and high-end equipment requirements, this assay holds significant potential for real-time food safety monitoring and rapid screening in resource-limited settings.