Development of loop-mediated isothermal amplification(LAMP) method for detection of E.coli O157:H7

Objective To establish a method of loop-mediated isothermal amplification(LAMP) for detection of E.coli O157:H7. Methods A set of four primers including two outer and two inner primers which specifically to recognize the rfbE gene of E.coli O157:H7 was designed. The LAMP reaction mix was optimized. To compare with standard method (GB/T 4789.36-2008),76 samples were tested. Results The LAMP assay correctly identified 27 E.coli O157:H7 strains,but 14 non-E.coli O157:H7 strains. Sensitivity of the LAMP assay for direct detection of E.coli O157:H7 in pure cultures and in spiked chicken samples was 2.7×101 CFU/mL. With this method,the detection of E.coli O157:H7 can be finished in less than 2 hours. The coincidence between LAMP and standard method are 96.1%. Conclusion The LAMP assay is a sensitive,rapid and simple tool for the detection of E.coli O157:H7 and will facilitate the surveillance for control of contamination of E.coli O157:H7.