A chemical study of the sugar composition of the polysaccharide portion of lipopolysaccharides isolated from Vibrio cholerae non-O1 from O2 to O155

Summary We describe here a chemical study on the sugar composition of the polysaccharide portion of lipopolysaccharide (LPS) isolated from strains of Vibrio cholerae non-O1. The strains of 154 O-forms (from O2 to O155) were classified into 111 chemotypes within the results obtained in this study. Glucosamine and fructose, known as component sugars of the core region of the LPS from V. cholerae O1, were not detected in the polysaccharide portions of LPS from strains that belonged to 12 chemotypes (14 O-forms) and 44 chemotypes (56 O-forms), respectively, indicating that variations are possible in the chemical structure of the core region of LPS of V. cholerae non-O1. Several thiobarbituric acid reaction-positive compounds were detected in the polysaccharide portions from strains that belonged to 17 chemotypes (17 O-forms). However, 2-keto-3-deoxyoctonic acid (KDO) was not identified in the polysaccharide portions of LPS from all strains of 154 O-forms examined. The chemotyping of all O-forms of V. cholerae non-O1 to date demonstrates that V. cholerae O1 does not correspond to any chemotype of V. cholerae non-O1 examined to date.