Jackson M P
Wayne State University School of Medicine, Department of Immunology and Microbiology, Detroit, MI 48201.
Mol Cell Probes. 1992 Jun;6(3):209-14. doi: 10.1016/0890-8508(92)90018-s.
Epidemiological studies have demonstrated that enterohaemorrhagic strains of Escherichia coli which cause the haemolytic uremic syndrome in humans and the oedema disease in pigs more frequently produce Shiga-like toxin type II (SLT-II) than any other member of the Shiga-like toxin family. A technique has been developed for the identification of SLT-II producing E. coli using the polymerase chain reaction (PCR) and a digoxigenin (DIG)-labelled DNA probe to facilitate the early detection and epidemiological analysis of these pathogens. Whole cell DNA liberated from isolated colonies during the denaturation step of PCR was amplified using a primer pair which is homologous to the slt-II gene sequences. The amplification products were transferred directly to a nitrocellulose membrane or following agarose gel electrophoresis and DNA denaturation. A chemically labelled DNA probe, prepared using PCR with the incorporation of DIG, was used to identify the PCR products of strains which produced SLT-II or a variant of SLT-II.
流行病学研究表明，能引起人类溶血尿毒综合征和猪水肿病的肠出血性大肠杆菌菌株，比志贺样毒素家族的任何其他成员更频繁地产生II型志贺样毒素（SLT-II）。已开发出一种利用聚合酶链反应（PCR）和地高辛配基（DIG）标记的DNA探针来鉴定产SLT-II大肠杆菌的技术，以促进对这些病原体的早期检测和流行病学分析。在PCR变性步骤中从分离菌落释放的全细胞DNA，使用与slt-II基因序列同源的引物对进行扩增。扩增产物直接转移到硝酸纤维素膜上，或在琼脂糖凝胶电泳和DNA变性后转移。使用通过掺入DIG的PCR制备的化学标记DNA探针，来鉴定产生SLT-II或SLT-II变体的菌株的PCR产物。
