Rapid detection of Escherichia Coli O157: H7 in meat using an improved loop-mediated isothermal amplification technology

Abstract:

The detection period of Escherichia coli O157: H7 (E. coli O157: H7) using traditional testing methods is relatively long. Therefore a kind of rapid detection method, namely a loop-mediated isothermal amplification (LAMP) technology with two loop primers detection E. coli O157: H7 in meat, was developed to address this problem. Two sets LAMP primers with loop primers were respectively designed based on the target sequences of rfbE and fliC genes of E. coli O157: H7. The detection results were judged by observing the white precipitate at simultaneous detection of single-tube. The specificity of the improved LAMP was verified using 36 strains of bacteria. DNA extracted by pyrolysis was amplified 20 min by the LAMP system. The detecting sensitivity of E. coli O157: H7 was 1.4 CFU/mL. The detection limit of E. coli O157: H7 from artificial contamination meat was 1.8 CFU/g. One false positive of 137 meat samples was detected, which can obtain compliance rate of 99.3% with the industry standard SNT0973-2000.

Key words:Loop-mediated isothermal amplification, LAMP, Detection, Escherichia coli O157: H7, Meat