Structural studies of the O-chains of the lipopolysaccharides produced by strains of Actinobacillus (Haemophilus) pleuropneumoniae serotype 5.

The water-phase lipopolysaccharides isolated by phenol-water extraction from the cells of four strains of Actinobacillus pleuropneumoniae serotype 5 (K17, L20, B78-3760, and 81-750) were shown on structural analysis to have O-chain components with the same basic polysaccharide structure of a linear unbranched homopolymer of 1,6-linked beta-D-galactopyranosyl residues, although the linear length of the O-chain varied among different strains. While those of strains B78-3760 and 81-750 were partially O-acetylated, the O-chains of strains K17 and L20 were unsubstituted.