Establishment of LAMP-CRISPR/Cas12a for rapid detection of Escherichia coli O157:H7 and one-pot detection.

Escherichia coli O157:H7 is a pathogenic serotype of Escherichia coli. Consumption of food contaminated with E. coli O157:H7 could cause a range of diseases. Therefore, it is of great importance to establish rapid and accurate detection methods for E. coli O157:H7 in food. In this study, based on LAMP and combined with the CRISPR/cas12a system, a sensitive and specific rapid detection method for E. coli O157:H7 was established, and One-Pot detection method was also constructed. The sensitivity of this method could stably reach 9.2 × 10° CFU/mL in pure culture, and the whole reaction can be completed within 1 h. In milk, E. coli O157:H7 with an initial contamination of 7.4 × 10° CFU/mL only needed to be cultured for 3 h to be detected. The test results can be judged by the fluorescence curve or by visual observation under a UV lamp, eliminating instrument limitations and One-Pot detection can effectively prevent the problem of false positives. In a word, the LAMP-CRISPR/cas12a system is a highly sensitive and convenient method for detecting E. coli O157:H7.