RAPID DETECTION OF Salmonella spp. IN MEAT BY LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (LAMP)

Abstract

Salmonella is the main pathogens that contaminate animal products and cause human Salmonella food poisoning. The objective of this study establish a rapid detection process for Salmonella spp. in meat samples by Loop Mediated Isothermal Amplification (LAMP) method specific to invA gene, meeting the requirements of analytical applications. The results of the study have built direct analysis processes of Salmonella from food based on the Loop Mediated Isothermal Amplification reaction, including: (1) Take meat sample (25 gram) are enriched in 150 ml Buffer Pepton Water (BPW): 75 ml Rappaport Vassiliadis Soya Broth (RVS) in a period of 10 hours, prior to DNA extraction for LAMP; (2) To improve the method of rapid DNA extraction from food enrichment fluid that using 100 mM NaOH buffer (meat), 5 minutes heating at 95°C, 30 seconds ultrasound, 10.000 rpm/g centrifugation in 2 minutes of collection DNA for LAMP reaction. The results of evaluating of method show that the LAMP method have sensitivity (SE) is 100%, accuracy is (AC) 94%, specificity (SP) is 94%, the false positive rate is 6% and false negative rate is 0%. The above results indicate the LAMP has been set up and the standard method according to TCVN 10780-1:2017 (ISO 6579-1:2017) are equivalent for detection of Salmonella in meat, but the time for analysising  of LAMP is shorter, only 10 hours.