title: Structure of the capsular polysaccharides and lipopolysaccharides from Haemophilus parasuis strains ER-6P (serovar 15) and Nagasaki (serovar 5).
abstract: Haemophilus parasuis is a Gram-negative bacterium from the family Pasteurellaceae and a swine pathogen. H. parasuis is found in the upper respiratory tract of piglets and produces Glässer's disease, an invasive disease characterized by polyserositis. H. parasuis contains a short lipopolysaccharide (LPS) or lipooligosaccharide (LOS) reported to play a partial role in interaction with host cells. The presence of capsule has been phenotypically demonstrated in certain H. parasuis strains and its role in virulence has been suggested, but the chemical structure of the surface polysaccharides of this bacterium was unknown. The structure of capsular polysaccharide (CPS) and LOS from virulent strains ER-6P and Nagasaki was studied by NMR spectroscopy, mass spectrometry and chemical methods. CPS from both strains had the same main chain with disaccharide repeating unit, substituted with α-Neu5R-(2-3)-α-GalNAc-(1-P-(strain ER-6P) or α-Neu5R-(2-3)-α-Gal-(1-P-strain Nagasaki) side chains, where R is the N-acetyl or N-glycolyl group. Glycolyl-neuraminic acid is widely found in animal glycoproteins, but it apparently has not been found in bacteria before, and might be important for the biology of this microorganism. Ac and Gc were present in equal amounts in the strain ER-6P but Nagasaki contained only about 20% of Gc substituent. Both strains produced the same LPS of a rough type with a single phosphorylated Kdo linking core and lipid A parts. LOS structure was similar to some strains of H. influenzae and contained a globotetraose terminal sequence.
authors.affiliation: National Research Council, Ottawa, ON, Canada.
authors.forename: Malcolm B
authors.initials: MB
authors.lastname: Perry
authors.forename: Leann L
authors.initials: LL
authors.lastname: MacLean
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.forename: Virginia
authors.initials: V
authors.lastname: Aragon
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
mesh_terms: D016667:Bacterial Capsules / Q000737:chemistry*; D001886:Bordetella pertussis / Q000737:chemistry*; D002240:Carbohydrate Sequence; D008070:Lipopolysaccharides / Q000737:chemistry*; D008969:Molecular Sequence Data; D013045:Species Specificity
chemical_list: D008070:Lipopolysaccharides
keywords: 3-deoxy-d-manno-octulosonic acid; Ac; CE–MS; CPS; Capillary electrophoresis–mass spectrometry; Capsule; DOC-PAGE; DeOxyCholate PolyAcrylamide Gel Electrophoresis; Gc; HMBC; HSQC; Haemophilus parasuis; Heteronuclear Multiple Bond Correlation; Heteronuclear Single Quantum Coherence; Kdo; LOS; LPS; Lipopolysaccharide; NMR; Nuclear Magnetic Resonance; Polysaccharide; ROESY; Rotating frame Overhause Effect Spectroscopy; TOCSY; Total Correlation Spectroscopy; acetyl; capsular polysaccharide; gCOSY; glycolyl; gradient COrrelation Spectroscopy; lipooligosaccharide; lipopolysaccharide