ABSTRACT:

Travellers' diarroea is a major cause of illness among travellers to developing countries, with enterotixigenic E.coli (ETEC) infection being the most common cause. Specific antibody in the small intestine, which inhibits ETEC firbriae mediated adhesion is an important mechanism for protection against ETEC infection. The aim is to develop a hyperimmune colostrum product, containing specific antibodies, which can be included within nutritional carriers to help prevent TD. A prototype product was tested in an intestinal cell model using Caco-2 tissue culture.

Prior to calving, dairy cows were vaccinated with a multivalent ETEC vaccine. Colostrum was collected from cows and pooled according to specific antibody titres and spray dried. Colostrum powder was reconstituted as a 5% w/v solution in distilled water and diluted 1/10 to 1/400. Caco-2 cells were grown to 14 days post-confluence to allow expression of intestinal characteristics. ETEC strains expressing three different types of fimbriae were incubated on the Caco-2 cells, with and without colostrum. Results indicate a dose dependent inhibition of adhesion of ETEC strains to the Caco-2 cells, with inhibition occurring up to a dilution of 1/200. The inhibition of adhesion indicates that a hyperimmune colostrum product taken orally may inhibit the intestinal colonisation of ETEC strains, the first step in the prevention of travellers diarrhoea.