Structural determination of the O-antigenic polysaccharide of enteropathogenic Escherichia coli O103:H2.

The structure of the antigenic O-polysaccharide isolated from the lipopolysaccharide produced by enterohemorrhagic Escherichia coli O103:H2 was determined and shown to be composed of d-glucose (1 part), 2-acetamido-2-deoxy-d-glucose (2 parts), 2-acetamido-2-deoxy-d-galactose (1 part), and 3-deoxy-3-(R)-3-hydroxybutyramido-d-fucose (1 part). From the results of methylation analysis, Smith-type periodate oxidation degradation studies, and the use of one- and two-dimensional (1)H and (13)C NMR spectroscopy, the O-polysaccharide antigen was found to be an unbranched polymer of a repeating pentasaccharide unit having the following structure: -->2)-Beta-d-Glcp-(1-->2)-Beta-d-Fucp3NBu-(1-->6)-alpha-d-GlcpNAc-(1-->4)-alpha-d-GalpNAc-(1-->3)-Beta-d-GlcpNAc-(1-->,where Bu is (R)-3-hydroxybutyramido.