High intracellular c-di-GMP levels antagonize quorum sensing and virulence gene expression in Burkholderia cenocepacia H111

Microbiology (Reading). 2017 May;163(5):754-764. doi: 10.1099/mic.0.000452. Epub 2017 May 3.

Abstract

The opportunistic human pathogen Burkholderia cenocepacia H111 uses two chemically distinct signal molecules for controlling gene expression in a cell density-dependent manner: N-acyl-homoserine lactones (AHLs) and cis-2-dodecenoic acid (BDSF). Binding of BDSF to its cognate receptor RpfR lowers the intracellular c-di-GMP level, which in turn leads to differential expression of target genes. In this study we analysed the transcriptional profile of B. cenocepacia H111 upon artificially altering the cellular c-di-GMP level. One hundred and eleven genes were shown to be differentially expressed, 96 of which were downregulated at a high c-di-GMP concentration. Our analysis revealed that the BDSF, AHL and c-di-GMP regulons overlap for the regulation of 24 genes and that a high c-di-GMP level suppresses expression of AHL-regulated genes. Phenotypic analyses confirmed changes in the expression of virulence factors, the production of AHL signal molecules and the biosynthesis of different biofilm matrix components upon altered c-di-GMP levels. We also demonstrate that the intracellular c-di-GMP level determines the virulence of B. cenocepacia to Caenorhabditis elegans and Galleria mellonella.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyl-Butyrolactones / metabolism
  • Animals
  • Burkholderia cenocepacia / genetics
  • Burkholderia cenocepacia / metabolism*
  • Burkholderia cenocepacia / pathogenicity*
  • Caenorhabditis elegans / microbiology
  • Cyclic GMP / analogs & derivatives*
  • Cyclic GMP / genetics
  • Cyclic GMP / metabolism
  • Fatty Acids, Monounsaturated / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial / genetics*
  • Moths / microbiology
  • Quorum Sensing / genetics*
  • Signal Transduction
  • Virulence / genetics
  • Virulence Factors / genetics
  • Virulence Factors / metabolism*

Substances

  • 2-dodecenoic acid
  • Acyl-Butyrolactones
  • Fatty Acids, Monounsaturated
  • Virulence Factors
  • bis(3',5')-cyclic diguanylic acid
  • Cyclic GMP