荧光型重组酶聚合酶扩增技术检测食品中大肠埃希氏菌O157

研究基于荧光型重组酶聚合酶扩增(exo-RPA)技术原理,建立了一种大肠埃希氏菌O157的快速检测方法。应用该方法对多种大肠埃希氏菌O157菌株和非大肠埃希氏菌O157菌株的检测结果表明,该方法的荧光探针和引物具有良好的特异性。对于梯度稀释的插入靶基因序列的质粒pUC57-rfbE和大肠埃希氏菌0157的检测,大肠埃希氏菌O157 exo-RPA检测灵敏度分别可以达到10~2 copies/μL和2.1×10~4 cfu/mL。对食品样品中大肠埃希氏菌0157的检测,exo-RPA方法显示出了良好的稳定性。并且食品样品中目标菌经4 h增菌后,该方法的灵敏性可以满足对食品样品中初始浓度为2.1×10~1 cfu/mL的目标菌的检测。因为大肠埃希氏菌exo-RPA方法配套设备简便、廉价,所以该方法可以在各级检测机构中推广,并适用于食品生产到消费各环节中大肠埃希氏菌0157的即时检测。

Detection of Food-Borne Escherichia Coli O157 Based on Fluorescence Probe-Based Recombinase Polymerase Amplification

This study developed a rapid detection method for Esceherichia coli O157 based on fluorescence probe-based recombinase polymerase amplification(exo-RPA).The results of detection several Escherichia coli O157 strains and non-Escherichia coli O157 strains by using exo-RPA assay showed that the fluorescence probe and primers of the detection method have high specificity.For the detection of gradient diluted pUC57-rfbE plasmids with target gene sequence and Escherichia coli 0157,the sensitivity of exo-RPA could reach 10~2 copies/μL and 2.1×10~4 cfu/mL,respectively.The results of detection of Escherichia coli 0157 in food samples indicate the Escherichia coli 0157 exo-RPA has good stability.Moreover,this method can be satisfied with the detection of low initial concentration(2.1×10~1 cfu/mL) of Escherichia coli O157 in food samples.Because of using the simple and low-cost supporting equipment,this method can be used and extended in departments at all levels for the point of care detection in each link from food production to consumption.