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.