Structural characterization of the lipopolysaccharide O-antigen from atypical isolate of Vibrioanguillarum strain 1282

Vibrio anguillarum is a Gram-negative bacterium associated with vibriosis in Atlantic cod (Gadus morhua L.). Although farmed cod in Norway is routinely vaccinated against the infection, outbreaks of V. anguillarum-associated vibriosis still occur. Here, we describe the structural characterization of the LPS O-chain polysaccharide (O-PS) from atypical isolates of V. anguillarum strain 1282 and show that it is distinct from that previously established for V. anguillarum serotype O2. The structure of the purified O-PS was shown by 1D/2D NMR (1H, 13C) spectroscopy and CE–MS studies to be a high-molecular mass linear polymer of tetrasaccharide repeating units, composed of 2-acetamido-3-(N-formyl-l-alanyl)amido-2,3-dideoxy-d-glucuronamide [GlcNAc3N(Fo-L-Ala)AN], 2-acetamido-3-acetamidino-2,3-dideoxy-d-mannuronic acid (ManNAc3NAmA), 3-acetamido-3-dideoxy-d-quinovose (Qui3NAc), and 2,4-diacetamido-2,4-dideoxy-d-fucose (FucNAc4NAc).Figure optionsDownload full-size imageDownload as PowerPoint slideNMR analysis of the partial hydrolysis-derived oligosaccharides confirmed the presence of an O-acetyl group at position O-4 of GlcNAc3N(Fo-l-Ala)AN and established that the above-mentioned structure represents the biological repeating unit of the O-PS. In addition, it was demonstrated that some of 2,3-diamino-2,3-dideoxy-glucuronamide in the O-PS was present in the form of 2,3-diamino-2,3-dideoxy-glucose.

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