A visual loop-mediated isothermal amplification combined with lateral flow dipstick (LAMP-LFD) method for rapid detection of Salmonella in foods

A new method for the rapid detection of Salmonella is described (Food Control, Vol 104, Pages 9-19 (2019) https://www.sciencedirect.com/science/article/pii/S0956713519301616). The method combines loop-mediated isothermal amplification with lateral flow dipstick (LAMP-LFD) targetting hilA gene. Compared with PCR and real-time PCR methods, the LAMP-LFD assay has the same specificity and higher sensitivity and required only 40 min (10 min for LFD detection) at 65 °C. The 52 strains of Salmonella tested, yielded positive results using the LAMP-LFD assay, and showed no cross-reactivity with 37 tested non-Salmonella strains. The detection limit of the LAMP-LFD assay was 6.7 CFU/mL (1000X more sensitive than conventional PCR and 100X more sensitive than real-time PCR). The new method could detect Salmonella in artificially contaminated food samples (milk, pork, beef, and chicken) when present as low as 144 CFU/mL or CFU/g and without the use of an enrichment step. After an enrichment step at 37 °C for 6 h, the results showed 100% accuracy compared to the standard culture-based.