A Chemotaxonomic Study of Vibrio fluvialis Based on the Sugar Composition of the Polysaccharide Portion of the Lipopolysaccharides

A chemotaxonomic study was carried out with a new serotyping scheme comprising 35 O-antigen groups of Vibrio fluvialis on the basis of the sugar composition of the polysaccharide portion of their lipopolysaccharide (LPS). A previously developed rapid method of preparing samples for compositional sugar analysis was employed. The 35 O-antigen groups were divided into 21 chemotypes. It is noted that a rarely occurring component sugar of gram-negative bacterial LPS, D-glycero-D-manno-heptose, and two kinds of uronic acids, i.e., galacturonic acid of a weakly bound type and glucuronic acid of a strongly bound type, were found in common in all the 21 chemotypes. A characteristic sugar component of gram-negative bacterial LPS, 2-keto-3-deoxyoctonate (KDO), was not detectable in any of the 21 chemotypes. Instead, three kinds of “KDO-like substances” were found, one in each of three chemotypes (III, XI and XVII). They were strongly positive in Weissbach's periodate-thiobarbituric acid test for KDO, but definitely not identical to it in high-voltage paper electrophoresis (HVPE); the substance present in chemotype XI was indicated by HVPE to be 3-deoxy-D-threo-hexulosonic acid which is a sugar constituent of Vibrio parahaemolyticus O7 and O12 LPS.