Role of PvdQ in Pseudomonas aeruginosa virulence under iron-limiting conditions

• Published in: Microbiology (Society for General Microbiology) 2010-01, Vol.156 (1), p.49-59
• Main Authors: Jimenez, Pol Nadal, Koch, Gudrun, Papaioannou, Evelina, Wahjudi, Mariana, Krzeslak, Joanna, Coenye, Tom, Cool, Robbert H, Quax, Wim J
• Format: Article
• Language: English
• Subjects: 4-Butyrolactone - analogs & derivatives; 4-Butyrolactone - biosynthesis; Amidohydrolases - genetics; Amidohydrolases - metabolism; Animals; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Biofilms - growth & development; Biological and medical sciences; Caenorhabditis elegans - microbiology; Fundamental and applied biological sciences. Psychology; Gene Deletion; Gene Expression Regulation, Bacterial; Homoserine - analogs & derivatives; Homoserine - biosynthesis; Iron - metabolism; Microbiology; Oligopeptides - biosynthesis; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Pseudomonas aeruginosa - enzymology; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - growth & development; Pseudomonas aeruginosa - pathogenicity; Solanum tuberosum - microbiology; Virulence
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.030973-0

1 Department of Pharmaceutical Biology, University of Groningen, 9713 AV Groningen, The Netherlands 2 Faculty of Pharmacy and Faculty of Technobiology, University of Surabaya, Indonesia 3 Laboratory for Pharmaceutical Microbiology, Ghent University, 9000 Ghent, Belgium PvdQ, an acylase from Pseudomonas aeruginosa PAO1, has been shown to have at least two functions. It can act as a quorum quencher due to its ability to degrade long-chain N -acylhomoserine lactones (AHLs), e.g. 3-oxo-C12-HSL, leading to a decrease in virulence factors. In addition, PvdQ is involved in iron homeostasis by playing a role in the biosynthesis of pyoverdine, the major siderophore of P. aeruginosa . In accordance with earlier studies on RNA level, we could show at the protein level that PvdQ is only expressed when iron is present at very low concentrations. We therefore set out to investigate the two functions of PvdQ under iron-limiting conditions. Gene deletion of pvdQ does not affect growth of P. aeruginosa but abrogates pyoverdine production, and results in an accumulation of 3-oxo-C12-HSL. Phenotypic analyses of our pvdQ mutant at low iron concentrations revealed that this mutant is impaired in swarming motility and biofilm formation. Additionally, a plant and a Caenorhabditis elegans infection model demonstrated that the deletion of pvdQ resulted in reduced virulence. None of the phenotypes in the present study could be linked to the presence or absence of AHLs. These results clearly indicate that under iron-limiting conditions PvdQ plays a major role in swarming motility, in biofilm development and in infection that is more likely to be linked to the pyoverdine pathway rather than the LasI/LasR/3-oxo-C12-HSL quorum-sensing circuit. Correspondence Wim J. Quax w.j.quax{at}rug.nl Abbreviations: AHL, N -acylhomoserine lactone; EDDHA, ethylenediamine di( o -hydroxy)phenylacetic acid; HSL, homoserine lactone These authors contributed equally to this work. A supplementary figure is available with the online version of this paper.