Structural characterization of the carbohydrate backbone of the lipopolysaccharide of Vibrio parahaemolyticus O-untypeable strain KX-V212 isolated from a patient Original Research Article

Vibrio parahaemolyticus strain KX-V212 of a novel serotype, which does not belong to any of the known 13 O-serotypes of this vibrio, was isolated from a patient. Its O-antigen harbors a unique strain-specific O-antigenic factor(s), in addition to that shared by the O-antigen of V. parahaemolyticus serotype O2. A carbohydrate backbone nonasaccharide was isolated from the lipopolysaccharide (LPS) of strain KX-V212 by dephosphorylation, reduction and deacylation and found to consist of one residue each of d-glucose, d-galactose, d-GlcN, 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) and 5-acetamido-7-(N-acetyl-d-alanyl)amino-3,5,7,9-tetradeoxy-d-glycero-d-galacto-non-2-ulosonic acid (Non5Ac7Ala), and two residues each of d-GlcA and l-glycero-d-manno-heptose (ld-Hep). Analysis of the isolated and deacylated lipid A showed that this oligosaccharide was an artifact resulting from a loss of one GlcN residue from the lipid A backbone. Therefore, the carbohydrate backbone