Characterization of the lipopolysaccharide O antigens of Actinobacillus pleuropneumoniae serotypes 9 and 11: antigenic relationships among serotypes 9, 11, and 1.
The antigenic lipopolysaccharide O polysaccharides of capsular serotypes 9 and 11 were examined by chemical, immunological, and nuclear magnetic resonance methods. Immunodiffusion tests carried out on these O antigens indicated that both contained common epitopes which were also shared by Actinobacillus pleuropneumoniae serotype 1. Chemical analysis and high-field nuclear magnetic resonance spectroscopy showed that the O antigens of serotypes 9 and 11 were high-molecular-weight polymers consisting of a backbone of repeating trisaccharide units composed of alpha-L-rhamnopyranosyl and alpha-D-glucopyranosyl residues (2:1). One of the alpha-L-rhamnose units forms a branch point and is stoichiometrically substituted with terminal 2-acetamido-2-deoxy-beta-D-glucose residues in the serotype 11 O polysaccharide, but only to the extent of 25% in the serotype 9 O polysaccharide. Thus, the serotype 9 O polysaccharide contains two different repeating units: a tetrasaccharide unit with the same structure as that of the serotype 11 O polysaccharide and a trisaccharide unit: [formula: see text] where R = beta-D-GlcpNAc for serotype 1 and 11 O polysaccharides, and R = H (75%) and R = beta-D-GlcpNAc (25%) for serotype 9. The structure of the previously determined serotype 1 O polysaccharide (E. Altman, J.-R. Brisson, and M. B. Perry, Biochem. Cell. Biol. 64:17-25, 1986) is identical to that of the serotype 11 O polysaccharide. We propose a more complete serotyping scheme for A. pleuropneumoniae which includes designation of both the capsular (K) and O antigens.
Beynon
L M
LM
Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario.
Griffith
D W
DW
Richards
J C
JC
Perry
M B
MB
D016977:Actinobacillus pleuropneumoniae / Q000145:classification / Q000276:immunology*; D002240:Carbohydrate Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D005779:Immunodiffusion; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D019081:O Antigens; D011135:Polysaccharides, Bacterial / Q000032:analysis* / Q000276:immunology; D012703:Serotyping
D000939:Epitopes; D019081:O Antigens; D011135:Polysaccharides, Bacterial