title: The extra-cytoplasmic function sigma factor sigX modulates biofilm and virulence-related properties in Pseudomonas aeruginosa.
abstract: SigX, one of the 19 extra-cytoplasmic function sigma factors of P. aeruginosa, was only known to be involved in transcription of the gene encoding the major outer membrane protein OprF. We conducted a comparative transcriptomic study between the wildtype H103 strain and its sigX mutant PAOSX, which revealed a total of 307 differentially expressed genes that differed by more than 2 fold. Most dysregulated genes belonged to six functional classes, including the "chaperones and heat shock proteins", "antibiotic resistance and susceptibility", "energy metabolism", "protein secretion/export apparatus", and "secreted factors", and "motility and attachment" classes. In this latter class, the large majority of the affected genes were down-regulated in the sigX mutant. In agreement with the array data, the sigX mutant was shown to demonstrate substantially reduced motility, attachment to biotic and abiotic surfaces, and biofilm formation. In addition, virulence towards the nematode Caenorhabditis elegans was reduced in the sigX mutant, suggesting that SigX is involved in virulence-related phenotypes.
authors.affiliation: Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France.
authors.forename: Gwendoline
authors.initials: G
authors.lastname: Gicquel
authors.forename: Emeline
authors.initials: E
authors.lastname: Bouffartigues
authors.forename: Manjeet
authors.initials: M
authors.lastname: Bains
authors.forename: Virginie
authors.initials: V
authors.lastname: Oxaran
authors.forename: Thibaut
authors.initials: T
authors.lastname: Rosay
authors.forename: Olivier
authors.initials: O
authors.lastname: Lesouhaitier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Connil
authors.forename: Alexis
authors.initials: A
authors.lastname: Bazire
authors.forename: Olivier
authors.initials: O
authors.lastname: Maillot
authors.forename: Magalie
authors.initials: M
authors.lastname: Bénard
authors.forename: Pierre
authors.initials: P
authors.lastname: Cornelis
authors.forename: Robert E W
authors.initials: RE
authors.lastname: Hancock
authors.forename: Alain
authors.initials: A
authors.lastname: Dufour
authors.forename: Marc G J
authors.initials: MG
authors.lastname: Feuilloley
authors.forename: Nicole
authors.initials: N
authors.lastname: Orange
authors.forename: Eric
authors.initials: E
authors.lastname: Déziel
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chevalier
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms; D018938:Caco-2 Cells; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000235:genetics; D004734:Energy Metabolism / Q000235:genetics; D006801:Humans; D009154:Mutation / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000502:physiology*; D012808:Sigma Factor / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics; D059467:Transcriptome / Q000235:genetics; D014774:Virulence / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; D037521:Virulence Factors