双抗夹心ELISA检测肠出血性大肠杆菌O157方法的建立

Establishment of double-antibody sandwich enzyme linked immunosorbent assay for detection of E.coli O157

以前期建立并纯化的肠出血性大肠杆菌O157:H7单克隆抗体3D6,建立一种适宜食品样品检测的双抗夹心ELISA检测方法。该方法只对O157菌株有特异性反应,对非O157型肠出血性大肠杆菌及其他菌株无交叉反应。敏感性试验结果表明,对大肠杆菌O157纯培养菌液检出限为1.2×105 CFU/mL。选择性增菌培养后,对牛肉、猪肉和鸡肉与模拟样品中的大肠杆菌O157的检出限为0.4～4CFU/g。

A rapid,specific and sensitive sandwich enzyme-linked immunosorbent assay（ELISA） was developed to detect E.coli O157 in food samples,which using polyclonal antibody as the capture antibody and monoclonal antibody 3D6 as the detection antibody.Antisera specific for E.coli O157 was prepared by intravenous injection into New Zealand rabbits with a stain of E.coli O157：H7.The detection limit of this sandwich ELISA was 1.2×105 CFU/mL E.coli O157 in pure culture with a high specificity,which was characterized by every non-O157 strain with negative response.The inoculated ground meat were tested to confirm efficiency of the method.With 12 h enrichment procedure,E.coli O157：H7 recovered well from inoculated ground meat at levels of 0.4-4 CFU/g.