Mannose-resistant haemagglutination and P antigen recognition are characteristic of Escherichia coli causing primary pyelonephritis.

Thirty-two Escherichia coli strains from 30 children with pyelonephritis were examined for their haemagglutination patterns and O and K serotypes. 29 (91%) of the strains showed mannose-resistant haemagglutination (MRHA). By use of well-defined target cells, these MRHA+ strains could be shown to recognise human cells either in a P-specific manner (recognising a specific galactosyl-galactose structure which is part of P blood groups antigens) or in a separate, X-specific manner. Both recognition mechanisms could occur separately or together on the same bacteria, the frequencies of P and X specificity being 81 and 19%, respectively. Both MRHA and P specificity were significantly associated with the O antigens 01, 04, 06, 016, and 018, and the capsular antigen K1, which have previously been associated with pyelonephritis. However, the association of MRHA and P specificity with upper urinary tract infection in children is greater than that of any other laboratory-defined bacterial characteristic.