Purification & antigenicity of Salmonella newport enterotoxin.

The enterotoxic moiety present in cell free culture supernatant (CFCS) of S. newport strains (MP/120 and BM/704) was purified and antigenically characterised. Purification was achieved to homogeneity by salt precipitation, dialysis and successive gel filtration through Sephadex G-100 and G-200 columns with the help of FPLC set. It was non-dialysable and purified enterotoxin yielded a single protein band in PAGE. It appeared to be of high molecular weight (100 KDa) and highly immunogenic in the rabbit. Antigenically, it was not related to cholera toxin, Shiga toxin or heat-labile enterotoxin of Escherichia coli.