The Klebsiella pneumoniae wabG gene: role in biosynthesis of the core lipopolysaccharide and virulence.
To determine the function of the wabG gene in the biosynthesis of the core lipopolysaccharide (LPS) of Klebsiella pneumoniae, we constructed wabG nonpolar mutants. Data obtained from the comparative chemical and structural analysis of LPS samples obtained from the wild type, the mutant strain, and the complemented mutant demonstrated that the wabG gene is involved in attachment to alpha-L-glycero-D-manno-heptopyranose II (L,D-HeppII) at the O-3 position of an alpha-D-galactopyranosyluronic acid (alpha-D-GalAp) residue. K. pneumoniae nonpolar wabG mutants were devoid of the cell-attached capsular polysaccharide but were still able to produce capsular polysaccharide. Similar results were obtained with K. pneumoniae nonpolar waaC and waaF mutants, which produce shorter LPS core molecules than do wabG mutants. Other outer core K. pneumoniae nonpolar mutants in the waa gene cluster were encapsulated. K. pneumoniae waaC, waaF, and wabG mutants were avirulent when tested in different animal models. Furthermore, these mutants were more sensitive to some hydrophobic compounds than the wild-type strains. All these characteristics were rescued by reintroduction of the waaC, waaF, and wabG genes from K. pneumoniae.
Izquierdo
Luis
L
Departamento de Microbiología y Parasitología Sanitarias, División de Ciencias de la Salud, Facultad de Farmacia,Universidad de Barcelona, Barcelona, Spain.
Coderch
Núria
N
Piqué
Nuria
N
Bedini
Emiliano
E
Corsaro
Maria Michela
MM
Merino
Susana
S
Fresno
Sandra
S
Tomás
Juan M
JM
Regué
Miguel
M
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005816:Genetic Complementation Test; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000378:metabolism* / Q000472:pathogenicity; D007928:Lethal Dose 50; D008070:Lipopolysaccharides / Q000096:biosynthesis* / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009154:Mutation; D010641:Phenotype; D018410:Pneumonia, Bacterial / Q000382:microbiology; D051381:Rats; D014552:Urinary Tract Infections / Q000382:microbiology; D014774:Virulence
D001426:Bacterial Proteins; D008070:Lipopolysaccharides