Adhesion of bovine enterotoxigenic Escherichia coli (ETEC) by type 1-like fimbriae

Enterotoxigenic Escherichia coli (STa+) strains were isolated from adult bovine with diarrhea. These strains did not express any known ETEC specific adhesins. Although hemagglutination with rat and sheep erythrocytes was observed in the presence of D-mannose (MRHA), these strains also showed mannose-sensitive hemagglutination (MSHA) with guinea-pig erythrocytes. Electron microscopic studies revealed the presence of fimbria-like structures (provisionally called 'F43ms') on bacterial cells grown at 37 degrees C but not on cells grown at 18 degrees C, However, it was observed by SDS-PAGE that the J-1 strain (F43ms(+)) produces a protein similar to F1 fimbriae, and this strain hybridized with a DNA probe for F1 fimbriae, Immunogold-labelling techniques indicated that a rabbit anti-serum is specific for F43ms fimbrial structures, but not for Type 1 fimbriae. The immunofluorescence test carried out with semipurified F43ms on bovine brush borders suggests that the fimbria-like structures are responsible for the adhesion to bovine epithelial cells.1374170024124