title: Structural and immunochemical studies of the lipopolysaccharide from the fish pathogen, Aeromonas bestiarum strain K296, serotype O18.
abstract: Chemical analyses and mass spectrometry were used to study the structure of the lipopolysaccharide (LPS) isolated from Aeromonas bestiarum strain K296, serotype O18. ESI-MS revealed that the most abundant A. bestiarum LPS glycoforms have a hexa-acylated or tetra-acylated lipid A with conserved architecture of the backbone, consisting of a 1,4'-bisphosphorylated β-(1→6)-linked D-GlcN disaccharide with an AraN residue as a non-stoichiometric substituent and a core oligosaccharide composed of Kdo1Hep6Hex1HexN1P1. 1D and 2D NMR spectroscopy revealed that the O-specific polysaccharide (OPS) of A. bestiarum K296 consists of a branched tetrasaccharide repeating unit containing two 6-deoxy-l-talose (6dTalp), one Manp and one GalpNAc residues; thus, it is similar to that of the OPS of A. hydrophila AH-3 (serotype O34) in both the sugar composition and the glycosylation pattern. Moreover, 3-substituted 6dTalp was 2-O-acetylated and additional O-acetyl groups were identified at O-2 and O-4 (or O-3) positions of the terminal 6dTalp. Western blots with polyclonal rabbit sera showed that serotypes O18 and O34 share some epitopes in the LPS. The very weak reaction of the anti-O34 serum with the O-deacylated LPS of A. bestiarum K296 might have been due to the different O-acetylation pattern of the terminal 6dTalp. The latter suggestion was further confirmed by NMR.
authors.affiliation: Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, Lublin 20-033, Poland. aturska@hektor.umcs.lublin.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Turska-Szewczuk
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.forename: Iwona
authors.initials: I
authors.lastname: Komaniecka
authors.forename: Alicja
authors.initials: A
authors.lastname: Kozinska
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Pekala
authors.forename: Adam
authors.initials: A
authors.lastname: Choma
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
mesh_terms: D000333:Aeromonas / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002347:Carps / Q000382:microbiology*; D008070:Lipopolysaccharides / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D011817:Rabbits; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D008070:Lipopolysaccharides