P-fimbriae of pyelonephritogenic Escherichia coli: identification and chemical characterization of receptors.

Pyelonephritogenic Escherichia coli isolates were found to be equal in their ability to adhere to uroepithelial cells and to cause agglutination specific for human erythrocytes. This adhesive capacity was not affected by D-mannose and was found to be mediated by a new class of E. coli fimbriae named P-fimbriae. Using human erythrocytes of different blood groups, we found the receptor molecules for P-fimbriae to be associated with the P blood group antigens, i. e. glycosphingolipids corresponding to the P blood group antigens P, P1 and Pk. By agglutination studies of erythrocytes with various set-ups of these antigens as well as by inhibition studies using synthetic saccharide derivatives and by coating non-agglutinable erythrocytes with a synthetic glycolipid, the minimal receptor structure was identified as the alpha-D-Galp-(1-4)-beta-D-Galp moiety of the carbohydrate portion of these glycosphingolipids. Similar experiments on isolated uroepithelial cells proved that these glycosphingolipids also constitute the receptors in the urinary tract.