O-antigenic lipopolysaccharide of Vibrio cholerae O139 Bengal, a new epidemic strain for recent cholera in the Indian subcontinent.

Lipopolysaccharide (LPS) from Vibrio cholerae O139 Bengal contained colitose (3,6-dideoxy-L-galactose) in addition to glucose, L-glycero-D-manno-heptose, fructose, glucosamine and quinovosamine in its polysaccharide and only glucosamine in lipid A, while perosamine, a characteristic component sugar of V. cholerae O1 LPS, was absent. 3-Hydroxydodecanoic, tetradecanoic and hexadecanoic acids as ester-bound fatty acids and 3-hydroxytetradecanoic acid as amide-bound fatty acid were identified in the lipid A. A very high serological specificity of O139 LPS distinct from that of O1 V. cholerae was demonstrated by passive hemolysis and passive hemolysis inhibition tests by using the LPS either as antigen for sensitizing sheep red blood cells or as inhibitor in the latter test.