title: Identification of biofilm-associated cluster (bac) in Pseudomonas aeruginosa involved in biofilm formation and virulence.
abstract: Biofilms are prevalent in diseases caused by Pseudomonas aeruginosa, an opportunistic and nosocomial pathogen. By a proteomic approach, we previously identified a hypothetical protein of P. aeruginosa (coded by the gene pA3731) that was accumulated by biofilm cells. We report here that a Delta pA3731 mutant is highly biofilm-defective as compared with the wild-type strain. Using a mouse model of lung infection, we show that the mutation also induces a defect in bacterial growth during the acute phase of infection and an attenuation of the virulence. The pA3731 gene is found to control positively the ability to swarm and to produce extracellular rhamnolipids, and belongs to a cluster of 4 genes (pA3729-pA3732) not previously described in P. aeruginosa. Though the protein PA3731 has a predicted secondary structure similar to that of the Phage Shock Protein, some obvious differences are observed compared to already described psp systems, e.g., this unknown cluster is monocistronic and no homology is found between the other proteins constituting this locus and psp proteins. As E. coli PspA, the amount of the protein PA3731 is enlarged by an osmotic shock, however, not affected by a heat shock. We consequently named this locus bac for biofilm-associated cluster.
authors.affiliation: Université de Rouen, Laboratoire Polymères, Biopolymères, Surfaces, CNRS FRE 3101, Plate-forme protéomique de l'IFRMP 23, Mont-Saint-Aignan, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Macé
authors.forename: Damien
authors.initials: D
authors.lastname: Seyer
authors.forename: Chanez
authors.initials: C
authors.lastname: Chemani
authors.forename: Pascal
authors.initials: P
authors.lastname: Cosette
authors.forename: Patrick
authors.initials: P
authors.lastname: Di-Martino
authors.forename: Benoit
authors.initials: B
authors.lastname: Guery
authors.forename: Alain
authors.initials: A
authors.lastname: Filloux
authors.forename: Marc
authors.initials: M
authors.lastname: Fontaine
authors.forename: Virginie
authors.initials: V
authors.lastname: Molle
authors.forename: Guy-Alain
authors.initials: GA
authors.lastname: Junter
authors.forename: Thierry
authors.initials: T
authors.lastname: Jouenne
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D001681:Biological Assay; D045744:Cell Line, Tumor; D019295:Computational Biology; D005798:Genes, Bacterial; D006017:Glycolipids / Q000378:metabolism; D018869:Heat-Shock Response; D006801:Humans; D007700:Kinetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation / Q000235:genetics; D009997:Osmotic Pressure; D011552:Pseudomonas Infections / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology*; D013499:Surface Properties; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D006017:Glycolipids; C418382:rhamnolipid