title: Structural and immunochemical relationship between the O-antigenic polysaccharides from the enteroaggregative Escherichia coli strain 396/C-1 and Escherichia coli O126.
abstract: The structure of the O-antigen polysaccharide (PS) from the enteroaggregative Escherichia coli strain 396/C-1 has been determined. Sugar and methylation analyses together with 1H and 13C NMR spectroscopy were the main methods used. Inter-residue correlations were determined by 1H,1H-NOESY, 1H,13C-heteronuclear multiple-bond correlation and dipole-dipole cross-correlated relaxation experiments. The PS is composed of pentasaccharide repeating units with the following structure: [structure: see text]. Analysis of NMR data reveals that on average the PS consists of approximately 13 repeating units and indicates that the biological repeating unit contains an N-acetylglucosamine residue at its reducing end. This structure is different to that reported for the O-antigen polysaccharide from E. coli O126. Monospecific anti-E. coli O126 rabbit serum from The International Escherichia and Klebsiella Centre did not distinguish between the E. coli strain 396/C-1 and the E. coli O126 reference strain, neither in slide agglutination nor in an indirect enzyme immunoassay. Subsequent successful serotyping of the E. coli strain 396/C-1 showed it to be E. coli O126:K+:H27.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden.
authors.forename: E Andreas
authors.initials: EA
authors.lastname: Larsson
authors.forename: Felipe
authors.initials: F
authors.lastname: Urbina
authors.forename: Zhennai
authors.initials: Z
authors.lastname: Yang
authors.forename: Andrej
authors.initials: A
authors.lastname: Weintraub
authors.forename: Göran
authors.initials: G
authors.lastname: Widmalm
mesh_terms: D002240:Carbohydrate Sequence; D004926:Escherichia coli / Q000737:chemistry* / Q000145:classification* / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry* / Q000276:immunology*
chemical_list: D019081:O Antigens