Structure of the O-chain of the phenol-phase soluble cellular lipopolysaccharide of Yersinia enterocolitica serotype O:9.

The phenol-phase soluble cellular lipopolysaccharide isolated by the phenol/water extraction method from Yersinia enterocolitica serotype O:9 cells was shown by hydrolytic, periodate oxidation, methylation and nuclear magnetic resonance studies to be an S-type lipopolysaccharide with a linear O-antigenic polysaccharide of 1,2-linked 4,6-dideoxy-4-formamido-alpha-D-mannopyranosyl units. The serological cross-reactivity between Y. enterocolitica serotype O:9 and the lipopolysaccharides of Vibrio cholerae and Brucella species can now be related to the presence of N-acylated 4-amino-4,6-dideoxy-alpha-D-mannopyranosyl residues in their respective O-antigenic chains.