Monoclonal antibodies against serotype specific and conserved epitopes in morphotype E Escherichia coli flagellins

Monoclonal antibodies (mAbs) were used to examine the interrelationships between morphologically identical flagellar filaments from Escherichia coli H serotype strains belonging to morphotype E. Serotype specific mAbs recognised epitopes exposed on the surface of flagellar filaments from H1, H7, H23, H49 and H51, but were inaccessible to immunolabelling in H45. Several mAbs which recognised conserved epitopes were also examined. mAb 7-56.1 recognised an epitope present in all morphotype E flagellins but not expressed on the filament surface. Similarly, mAb 1-5.1 recognised an internal epitope shared only by serotypes H1 and H12. Serotype H23 expressed a surface epitope which was present but not surface exposed in H7, H1 and H45 filaments.