N - 3 - Hydroxypropionyl - x - D - perosamine homopolymer constituting the 0 - chain of lipopolysaccharides from Vibrio bioserogroup 1875 possessing antigenic factor ( s ) in common with 01 Vibrio cholerae

In recent years, three groups of non-cholera vibrio possessing antigenic factor(s) in common with 0 1 Vibrio cholerae have been isolated in Japan, i.e. Vibrio bioserogroup 1875 [1], Vibriofluvialis Kobe [2] and non-Ol V. cholerae bioserogroup Hakata [3]. Isolation and chemical as well as serological characterizations, in particular, compositional sugar analysis, of their lipopolysaccharides (LPS) were carried out by our group [4-7]. Of particular interest is the fact that the 0-chain of LPS from non-Ol V. cholerae Hakata contains a linear (1 -+2)-linked N-acetyl-a-D-perosamine (4-acetamido-4,6-dideoxy-a-D-mannopyranose) homopolymer [7] which is very similar to, but not identical with, a linear (1 -+2)-linked N-3-deoxy-Lglycero-tetronyl(S-2,4-dihydroxybutyryl)-a-D-perosamine homopolymer which constitutes the 0-chain of 01 V. cholerae LPS [8,9]. 01 V. cholerae 0-antigen consists of three antigenic factors: group somatic antigen A, Ogawa antigen factor B and Inaba antigen factor C [10,11]. Vibrio bioserogroup 1875 (referred to as 1875 Original) was isolated from estuarine seawater in Osaka Bay, Japan. The 0-antigen of this group is composed of at least its own antigen factor (referred to as D) and the B and a small quantity of the C factors of 01 V. cholerae [1]. An antigenic variation similar to that found in 01 V. cholerae occurred in 1875 Original resulting in a variant (referred to as 1875 Variant) which possessed only factor C in addition to factor D [1]. In the present study, an unknown sugar, previously named NS II [4] and found in LPS of 1875 Original and its Inaba variant (1875 Variant), was identified as N-3-hydroxypropionyl-Dperosamine [4-(3-hydroxypropanamido)-4,6-dideoxy-D-mannopyranose]. Furthermore, the occurrence of a (1 -+2)-linked linear homopolymer of N-3-hydroxypropionyl-a-D-perosamine was demonstrated for the first time in the 0-chain of both 1875 Original and Variant. dideoxy-a-D-mannopyranose], which is very similar to, but not identical with, both (1-+2)-linked linear N-3-deoxy-L-glycerotetronyl(S-2,4-dihydroxybutyryl)-a.-D-perosamine homopolymer and (1 -+2)-linked linear N-acetyl-a.-D-perosamine homopolymer which constitute the 0-chains of 01 V. cholerae and non-Ol V. cholerae bioserogroup Hakata LPS respectively.