Serological and structural relationships between Escherichia coli O:98 and Yersinia enterocolitica O:11,23 and O:11,24 lipopolysaccharide O-antigens.

The serologically related lipopolysaccharide O-antigens of Yersinia enterocolitica serotypes 11,23 and 11,24 and of Escherichia coli O:98 were analysed by composition analysis, methylation, and the use of one- and two-dimensional nuclear magnetic resonance methods. They were found to be composed of the same basic linear unbranched polysaccharide of repeating tetrasaccharide units containing 2-acetamido-2-deoxy-D-glucose (D-GlcNAc), 2-acetamido-2-deoxy-D-galacturonic acid (D-GalNAcA), and 2-acetamido-2,6-dideoxy-L-glucose (L-quinovosamine, L-QuiNAc), having the structure -->3)-alpha-L-QuipNAc-(1-->4)-alpha-D-GalpNAcA-(1-->3)-alpha -L-QuipNAc-(1-->3)-beta-D-GlcpNAc-(1-->. The lipopolysaccharide O-antigens of E. coli O:98 and Y. enterocolitica O:11,24 were polymers of the above repeating unit, whereas that of Y. enterocolitica O:11,23 was a linear polymer of the same repeating units in which the alpha-D-GalpNAcA residues were stoichiometrically substituted by acetyl groups at O-3.