食品中大肠杆菌O157:H7的两种检测方法研究

Comparison of two methods on detecting Escherichia Coli O157∶H7 strain in foods

研究食品中大肠杆菌O157∶H7的两种检测方法,PCR法引物针对特异性粘附毒素基因(eaeA)扩增检测,双抗夹心ELISA采用鸡抗O157∶H7特异性脂多糖(LPS)抗体(IgY)检测,结果显示两种方法对纯培养物的检测灵敏度都在103～104cfu/mL之间,特异性能满足食品检测需求;PCR法的敏感度较ELISA法高,且较省时。经以牛奶为参考的食品模拟样品(37℃增菌14h)验证两种检测方法的最低检出限均为2.5cfu/25mL样品。

To detect Escherchia Coli O157 ∶ H7 in foods,two methods such as the double antibody sandwich enzyme-linked immunosorbent assay and PCR were developed.A specific primer had been successfully designed to amplify eaeA gene in PCR detection.In the double sandwich antibody ELISA,the specific anti-E.coli O157∶H7 LPS-IgY was used.As a result,the limits of tow detections were 103～104cfu/mL in pure culture of E.coli O157∶H7 and the PCR was a little higher and faster than ELISA. In analogue milk detection,the detection limits of two methods were all 2.5cfu/25mL after 14h enrichment.