Background: Salmonella enterica is a zoonotic pathogen of substantial concern to human and animal health and is a leading cause of morbidity and mortality in people worldwide. Loop-mediated isothermal amplification (LAMP) technology is a new type of nucleic acid amplification technology, which has the characteristics of high specificity, high sensitivity, simple operation, convenience, and low cost. This study aims to establish a rapid detection method for Salmonella based on LAMP technology. Methods: Primers were designed for Salmonella's specific conservative invA gene. Through primer screening and optimization of reaction conditions, and a LAMP method for detecting Salmonella with realtime fluorescence and visual observation results was established. The sensitivity and specificity of the method were assessed, and the accuracy was evaluated through the testing of Salmonella-contaminated and noncontaminated clinical samples.
Results:The optimal reaction temperature of LAMP was 60-65 ℃, and the optimal reaction time was 25-30 minutes. The detection limits of real-time fluorescence and visual observation were both 1.4 pg/μL. There was no cross-reactivity observed with 22 non-Salmonella species, and the specificity was 100%.Additionally, 30 samples contaminated with Salmonella, 30 samples not contaminated with Salmonella, and 8 clinical samples identified as positive by bacterial culture and microbial mass spectrometry were tested. The positive coincidence rate of the detection system was 97.4% by real-time fluorescence and 89.5% by visual observation, the negative coincidence rate was 100%, and the total coincidence rate was 98.5% and 94.1%, respectively.Conclusions: In the scene of infection, primary hospital, disaster area treatment and other scenarios, the conditions of environment, equipment and personnel was limited, therefore, the established real-time fluorescence and visual lamp method can provide a powerful means for the rapid detection of Salmonella.