title: A second outer-core region in Klebsiella pneumoniae lipopolysaccharide.
abstract: Up to now only one major type of core oligosaccharide has been found in the lipopolysaccharide of all Klebsiella pneumoniae strains analyzed. Applying a different screening approach, we identified a novel Klebsiella pneumoniae core (type 2). Both Klebsiella core types share the same inner core and the outer-core-proximal disaccharide, GlcN-(1,4)-GalA, but they differ in the GlcN substituents. In core type 2, the GlcpN residue is substituted at the O-4 position by the disaccharide beta-Glcp(1-6)-alpha-Glcp(1, while in core type 1 the GlcpN residue is substituted at the O-6 position by either the disaccharide alpha-Hep(1-4)-alpha-Kdo(2 or a Kdo residue (Kdo is 3-deoxy-D-manno-octulosonic acid). This difference correlates with the presence of a three-gene region in the corresponding core biosynthetic clusters. Engineering of both core types by interchanging this specific region allowed studying the effect on virulence. The replacement of Klebsiella core type 1 in a highly type 2 virulent strain (52145) induces lower virulence than core type 2 in a murine infection model.
authors.affiliation: Departamento de Microbiología i Parasitología Sanitarias, Facultad de Farmacia, Universidad de Barcelona, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Regué
authors.forename: Luis
authors.initials: L
authors.lastname: Izquierdo
authors.forename: Sandra
authors.initials: S
authors.lastname: Fresno
authors.forename: Núria
authors.initials: N
authors.lastname: Piqué
authors.forename: Maria Michela
authors.initials: MM
authors.lastname: Corsaro
authors.forename: Teresa
authors.initials: T
authors.lastname: Naldi
authors.forename: Cristina
authors.initials: C
authors.lastname: De Castro
authors.forename: Dietmar
authors.initials: D
authors.lastname: Waidelich
authors.forename: Susana
authors.initials: S
authors.lastname: Merino
authors.forename: Juan M
authors.initials: JM
authors.lastname: Tomás
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D007711:Klebsiella pneumoniae / Q000737:chemistry / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D007928:Lethal Dose 50; D008070:Lipopolysaccharides / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D014774:Virulence
chemical_list: D008070:Lipopolysaccharides