[Development and preliminary characterization of monoclonal antibodies to 987P adhesin antigen of E. coli].

A panel of 11 monoclonal antibodies (MAbs) to 987P adhesin antigen of E. coli were developed and partially characterized. They only reacted with E. coli strains bearing 987P adhesin but neither with other E. coli (K88+, K99+ and F41+) strains nor other species in family of Enterobacteriaceae in IF or ELISA. The amount of 987P+ bacteria which could be detected by the HRPO-conjugated MAb EPN3 was as small as 2 X 10(3) cells/ml, and the detected rate of fecal or intestinal samples from piglets with artificially induced diarrhoea by IF and/or ELISA was 4/4 and 6/6, respectively. The adhesion of 987P+ E. coli to porcine intestinal epithelial cells could be inhibited by seven of these MAbs in vitro. The binding pattern of MAb EPN2 with 987P fimbriae as shown in immunogold stain under electron microscope was periodic and discrete distribution along the length of each of the fimbriae. ELISA and IF blocking test suggested that there were at least 3 kinds of determinants on 987P adhesion. These MAbs were not only useful in identification of 987P fimbriae of enterotoxigenic E. coli, but also in the studies of its molecular structure and biological function.