Visual LAMP for Salmonella Detection on Soil for Vegetable Farming

  Objective  A visual loop-mediated isothermal amplification (LAMP) technique for rapid detection of Salmonella in soil was developed to facilitate the prevention and control of the pathogens in vegetable fields.

  Method  Based on the sequence of the invasion protein A (invA) of Salmonella, LAMP primers were designed and reaction system optimized. Specificity and sensitivity of the methodology were challenged by artificial inoculation and verified by the National Standard Detection Method for Salmonella Detection in Vegetable Cultivation Soil.

  Result  The LAMP reacted positively on Salmonella but negatively on 6 non-Salmonella strains. It showed a minimum detection limit of 7 CFU·25 μL⁻¹ and a sensitivity of 4×10²CFU·g⁻¹ on the artificially inoculated Salmonella. Compared with the standard method, the LAMP exhibited same testing accuracy.

  Conclusion  The newly developed visual LAMP assay was rapid, accurate and sensitive for the detection of Salmonella in soil for vegetable farming.