Development and Application of IMSA for Rapid Detection of Enterohaemorrhage Escherichia coli O157:H7

To establish and evaluate a rapid detection method for EHEC O157:H7 suitable for food and drug administration and grassroots inspection departments.To study the specific rfbE gene of EHEC O157:H7, using Isothermal multiple self-matching-initiated amplification (IMSA) to design and perform testing. The specificity test and sensitivity test were carried out and compared with the fluorescence quantitative PCR method. The IMSA method was used to determine the shortest incubation time and the lowest detection sensitivity of artificial contaminated samples. IMSA method and national standard method were used to examine 24 different meat products to evaluate their consistency. The results showed that: This method only amplified EHEC O157:H7 specifically. The sensitivity of IMSA was higher than that of qPCR, up to 8.9×10² CFU/mL. The IMSA method could be used to detect artificially contaminated bacterial samples for the shortest time of 10 h, and the detection limit was 9.1 CFU /25 g. The IMSA method was 100% consistent with the conventional culture method in 24 meat samples. Conclusion: IMSA technology has the characteristics of strong specificity, high sensitivity, rapid and accurate resμLts, and can be used to detect EHEC O157:H7 in food within 11 hours. It is suitable for food and drug administration and basic inspection departments to detect EHEC O157:H7 quickly.