大肠杆菌热敏肠毒素的检测及纯化

Detection and Preparation of E.coli Heat-labile Enterotoxin(LT)

采用平板免疫溶血试验、兔回肠结扎试验,探讨了大肠杆菌耐热肠毒素制备的方法和检测方法。试验表明:平板免疫溶血试验能够快速灵敏地检测出热敏感肠毒素,并具有很强的特异性,比肠结扎试验灵敏度高,而且简便易行;试验将细菌接种到产毒素培养基上培养,进行增菌,然后离心取上清液,沉淀溶于PBS液中用多黏菌素B浸出,均用80%饱和度的(NH4)2SO4盐析,之后用SephadexG-100凝胶层析分离纯化,最后用SDS-聚丙烯酰胺凝胶电泳检测热敏肠毒素的纯度。

The heat-labile enterotoxin of porcine E.coli isolates was assayed by plate immune hemolysis assay （PIHA） and ligation of rabbit ileum （LRI）, the positive result rate by PIHA and LRI was higher than that by BSRS. The purification method was studied and modified bacteria was dealt with by polymyxin B sulfate. After being precipitated by 80 % ammonium sulfate the LT was isolated and purified through Sephadex G-100 column chromatography and identified by SDS-PAGE.