title: The identification of wadB, a new glycosyltransferase gene, confirms the branched structure and the role in virulence of the lipopolysaccharide core of Brucella abortus.
abstract: Brucellosis is a worldwide extended zoonosis caused by Brucella spp. These gram-negative bacteria are not readily detected by innate immunity, a virulence-related property largely linked to their surface lipopolysaccharide (LPS). The role of the LPS lipid A and O-polysaccharide in virulence is well known. Moreover, mutation of the glycosyltransferase gene wadC of Brucella abortus, although not affecting O-polysaccharide assembly onto the lipid-A core section causes a core oligosaccharide defect that increases recognition by innate immunity. Here, we report on a second gene (wadB) encoding a LPS core glycosyltransferase not involved in the assembly of the O-polysaccharide-linked core section. As compared to wild-type B. abortus, a wadB mutant was sensitive to bactericidal peptides and non-immune serum, and was attenuated in mice and dendritic cells. These observations show that as WadC, WadB is also involved in the assembly of a branch of Brucella LPS core and support the concept that this LPS section is a virulence-related structure.
authors.affiliation: Departamento de Microbiología y Parasitología e Instituto de Salud Tropical, Universidad de Navarra, 31008 Pamplona, Spain. Electronic address: ygilrami@alumni.unav.es.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Gil-Ramírez
authors.affiliation: Departamento de Microbiología y Parasitología e Instituto de Salud Tropical, Universidad de Navarra, 31008 Pamplona, Spain. Electronic address: rconde@unav.es.
authors.forename: Raquel
authors.initials: R
authors.lastname: Conde-Álvarez
authors.affiliation: Departamento de Microbiología y Parasitología e Instituto de Salud Tropical, Universidad de Navarra, 31008 Pamplona, Spain. Electronic address: lpalacios@alumni.unav.es.
authors.forename: Leyre
authors.initials: L
authors.lastname: Palacios-Chaves
authors.affiliation: Departamento de Microbiología y Parasitología e Instituto de Salud Tropical, Universidad de Navarra, 31008 Pamplona, Spain. Electronic address: azuniga@unav.es.
authors.forename: Amaia
authors.initials: A
authors.lastname: Zúñiga-Ripa
authors.affiliation: Instituto de Agrobiotecnología (CSIC-Universidad Pública de Navarra-Gobierno de Navarra), 31006 Pamplona, Spain. Electronic address: mariajesus.grillo@unavarra.es.
authors.forename: María-Jesús
authors.initials: MJ
authors.lastname: Grilló
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University, Centre d'Immunologie de Marseille-Luminy, 13288 Marseille, France; INSERM U1104, 13288 Marseille, France; CNRS UMR7280, 13288 Marseille, France. Electronic address: arce@ciml.univ-mrs.fr.
authors.forename: Vilma
authors.initials: V
authors.lastname: Arce-Gorvel
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University, Centre d'Immunologie de Marseille-Luminy, 13288 Marseille, France; INSERM U1104, 13288 Marseille, France; CNRS UMR7280, 13288 Marseille, France. Electronic address: hanniffy@ciml.univ-mrs.fr.
authors.forename: Sean
authors.initials: S
authors.lastname: Hanniffy
authors.affiliation: Departamento de Microbiología y Parasitología e Instituto de Salud Tropical, Universidad de Navarra, 31008 Pamplona, Spain. Electronic address: imoriyon@unav.es.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Moriyón
authors.affiliation: Departamento de Microbiología y Parasitología e Instituto de Salud Tropical, Universidad de Navarra, 31008 Pamplona, Spain. Electronic address: miriart@unav.es.
authors.forename: Maite
authors.initials: M
authors.lastname: Iriarte
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D001770:Blood Bactericidal Activity; D002003:Brucella abortus / Q000737:chemistry* / Q000472:pathogenicity*; D003713:Dendritic Cells / Q000382:microbiology; D005260:Female; D017353:Gene Deletion; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000633:toxicity*; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D050296:Microbial Viability; D014774:Virulence
chemical_list: D023181:Antimicrobial Cationic Peptides; D008070:Lipopolysaccharides; D016695:Glycosyltransferases
keywords: Brucella; Glycosyltransferase; Lipopolysaccharide; Virulence; wadB; wadC