title: A gene, uge, is essential for Klebsiella pneumoniae virulence.
abstract: Klebsiella pneumoniae strains typically express both smooth lipopolysaccharide (LPS) with O antigen molecules and capsule polysaccharide (K antigen) on the surface. A single mutation in a gene that codes for a UDP galacturonate 4-epimerase (uge) renders a strain with the O-:K- phenotype (lack of capsule and LPS without O antigen molecules and outer core oligosaccharide). The uge gene was present in all the K. pneumoniae strains tested. The K. pneumoniae uge mutants were unable to produce experimental urinary tract infections in rats and were completely avirulent in two different animal models (septicemia and pneumonia). Reintroduction of the single uge wild-type gene in the corresponding mutants completely restored the wild-type phenotype (presence of capsule and smooth LPS) independently of the O or K serotype of the wild type. Furthermore, complemented uge mutants recovered the ability to produce experimental urinary tract infections in rats and virulence in the septicemia and pneumonia animal models.
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, 08071 Barcelona, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Regué
authors.forename: Beatriz
authors.initials: B
authors.lastname: Hita
authors.forename: Nuria
authors.initials: N
authors.lastname: Piqué
authors.forename: Luis
authors.initials: L
authors.lastname: Izquierdo
authors.forename: Susana
authors.initials: S
authors.lastname: Merino
authors.forename: Sandra
authors.initials: S
authors.lastname: Fresno
authors.forename: Vicente Javier
authors.initials: VJ
authors.lastname: Benedí
authors.forename: Juan M
authors.initials: JM
authors.lastname: Tomás
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002238:Carbohydrate Epimerases / Q000235:genetics* / Q000378:metabolism; D002240:Carbohydrate Sequence; D004195:Disease Models, Animal; D005260:Female; D020043:Genes, Essential; D007710:Klebsiella Infections / Q000382:microbiology / Q000503:physiopathology; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000472:pathogenicity*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D018410:Pneumonia, Bacterial / Q000382:microbiology / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA; D014552:Urinary Tract Infections / Q000382:microbiology / Q000503:physiopathology*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D002238:Carbohydrate Epimerases