Abstract
Previous studies have suggested that the airways of cystic fibrosis (CF) patients have elevated sodium chloride (NaCl) levels due to the malfunctioning of the CF transmembrane conductance regulator protein. For bacteria to survive in this high-salt environment, they must adjust by altering the regulation of gene expression. Among the different bacteria inhabiting the airways of CF patients is the opportunistic pathogen Burkholderia cenocepacia. Previous studies have indicated that B. cenocepacia produces a toxin and cable pili under high osmolar conditions. We used transposon mutagenesis to identify NaCl-regulated genes in the clinical strain B. cenocepacia K56-2. Six transconjugants were induced with increasing NaCl concentration. The DNA flanking the transposon was sequenced and five distinct open reading frames were identified encoding the following putative proteins: an integrase, an NAD-dependent deacetylase, TolB, an oxidoreductase, and a novel hypothetical protein. The collective results of this study provide important information about the physiology of B. cenocepacia when faced with osmotic stress and suggest the identity of significant virulence mechanisms in this opportunistic pathogen.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Altschul SF, Madden TL, Schaffer AA et al (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25:3389–3402
Ausubel F, Brent M, Kingston RE et al (1989) Current protocols in molecular biology. Wiley, New York
Bernadac A, Gavioli M, Lazzaroni J et al (1998) Escherichia coli tol-pal mutants form outer membrane vesicles. J Bacteriol 180:4872–4878
Brachmann CB, Sherman JM, Devine SE et al (1995) The SIR2 gene family, conserved from bacteria to humans, functions in silencing, cell cycle progression and chromosome stability. Genes Dev 9:2888–2902
Cheung KJ, Baarinarayana V, Selinger DW et al (2003) A microarray-based antibiotic screen identifies a regulatory role or supercoiling in the osmotic stress response of Escherichia coli. Genome Res 13:206–215
Darling P, Chan M, Cox AD et al (1998) Siderophore production by cystic fibrosis isolates of Burkholderia cepacia. Infect Immun 66:874–877
Gilligan PH (1991) Microbiology of airway disease in patients with cystic fibrosis. Clin Microbiol 4:35–51
Heilpern AJ, Waldor MK (2000) CTXΦ infection of Vibrio cholerae requires the tolQRA gene products. J Bacteriol 182:1739–1747
Huber B, Feldmann F, Kothe M et al (2004) Identification of a novel virulence factor in Burkholderia cenocepacia H111 required for efficient slow killing of Caenorhabditis elegans. Infect Immun 72:7220–7230
Isles A., Maclusky I, Corey M et al (1984) Pseudomonas cepacia infection in cystic fibrosis: an emerging problem. J Pediatr 104:206–210
Kaerberlein M., Andalis AA, Fink GR et al (2002) High osmolarity extends life span in Saccharomyces cerevisiae by a mechanism related to calorie restriction. Mol Cell Biol 22:8056–8066
Lonon MK, Morris-Hooke A (1991) A nonhemolytic phospholipase C produced by Pseudomonas cepacia. Curr Microbiol 23:139–142
McKevitt AI, Bajaksouzian S, Klinger JD et al (1989) Purification and characterization of an extracellular protease from Pseudomonas cepacia. Infect Immun 57:771–778
Merriman TR, Lamont IL (1993) Construction and use of a self-cloning promoter probe vector for gram-negative bacteria. Gene 126:17–23
Miller J (1972) Experiments in molecular genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY
Mohr CD, Tomich M, Herfst CA (2001) Cellular aspects of Burkholderia cepacia infection. Microb Infect 3:425–435
Neidhardt FC, Curtiss R (1996) Escherichia coli and Salmonella: cellular and molecular biology. 2nd ed. ASM Press, Washington, DC
Schwan WR, Lee JL, Lenard FA et al (2002) Osmolarity and pH growth conditions regulate fim gene transcription and type 1 pilus expression in uropathogenic Escherichia coli. Infect Immun 70:1391–1402
Smith JJ, Travis SM, Greenberg EP et al (1996) Cystic fibrosis airway epithelia fail to kill bacteria because of abnormal airway surface fluid. Cell 85:229–236
Sokol PA, Darling P, Woods DE et al (1999) Role of ornibactin biosynthesis in the virulence of Burkholderia cepacia:characterization of pvdA, the gene encoding L-ornithine N5-oxygenase. Infect Immun 67:4443–4455
Starai VJ, Celic I, Cole RN et al (2002) Sir2-dependent activation of acetyl-CoA synthetase by deacetylation of active lysine. Science 298:2390–2392
Sturgis JN (2001) Organisation and evolution of the tol-pal gene cluster. J Mol Microbiol Biotechnol 3:113–122
Tan MW, Mahajan-Miklos S, Ausubel FM (1999) Killing of Caenorhabditis elegans by Pseudomonas aeruginosa used to model mammalian bacterial pathogenesis. Proc Natl Acad Sci USA 96:715–720
Tomich M, Mohr CD (2004) Transcriptional and posttranscriptional control of cable pilus gene expression in Burkholderia cenocepacia. J Bacteriol 186:1009–1020
Webster RE (1991) The tol gene products and the import of macromolecules into Escherichia coli. Mol Microbiol 5:1005–1011
Weingart CL, White CE, Liu S et al (2005) Direct binding of the quorum sensing regulator CepR of Burkholderia cenocepacia to two target promoters in vitro. Mol Microbiol 57:452–467
Zabner J, Smith JL, Karp PH et al (1998) Loss of CFTR chloride channels alters salt absorption by cystic fibrosis airway epithelial in vitro. Mol Cell 2:397–403
Acknowledgments
This work was funded in part by the Polly and Reid Anderson Endowment in the Sciences, the Student Research and Grants Committee from Denison University, and the Howard Hughes Early Research Experience
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bhatt, S., Weingart, C.L. Identification of Sodium Chloride-Regulated Genes in Burkholderia cenocepacia . Curr Microbiol 56, 418–422 (2008). https://doi.org/10.1007/s00284-008-9114-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00284-008-9114-z