Rapid Detection of Enterohemorrhagic Escherichia coli O157:H7 in Food by Loop-Mediated Isothermal Amplification Assay

Objective To develop a rapid and simple method of loop-mediated isothermal amplification(LAMP) for detecting Escherichia coli(E.coli) O157:H7 in foods.Method Based on the characteristic conserved sequence of lipopolysaccharide gene(rfbE,GenBank S83460) of O157 antigen and flagellin gene(fliC,GenBank L07388) of H7 antigen,the loop-mediated isothermal amplification method was developed to detect the specificity of twenty-one E.coli O157:H7 strains and non E.coli O157:H7 strains.The results of LAMP were compared with polymerase chain reaction(PCR).The feasibility of LAMP was evaluated by detecting E.coli O157:H7 in food samples.Results The detection could be finished by LAMP within 1 h;The sensitivity was 96.72%,the specificity was 85.71% and the accuracy was 93.26%.Conclusion The sensitivity of LAMP was higher than that of PCR.LAMP is a simple,rapid method suitable for screening E.coli O157:H7 in suspicious samples.