A new principle for prevention of diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) possessing colonization factor antigen (CFA/I).

The infant rabbit model, developed to study human ETEC with CFA/I (Evans et al., 1975), was used to evaluate agarose (Sepharose) gel substituted with a hydrophobic ligand for prevention of diarrhoeal symptoms. In a group of rabbits given 0.02 g of palmitoyl Sepharose 1 h after an oral infection with 10(9) ETEC organisms with CFA/I antigen, only 2/11 animals developed diarrhoea, while in control groups given the unsubstituted Sepharose (hydrophilic) gel or ETEC organisms alone, all animals developed diarrhoea. In groups of rabbit given the hydrophobic gel 6 h after the ETEC organisms, only 2/6 animals showed a short period of diarrhoea. The "hydrophobic principle" to prevent ETEC infections will be studied in other animal models and in human volunteers.