Cellular signaling and molecular regulation governing motility, biofilm formation, and virulence in the Bacillus cereus group
Appears in the following Collection
- Farmasøytisk institutt 
AbstractThe bacterium Bacillus cereus is increasingly recognized as a major source of food-borne disease, as well as other severe infections. Biofilms are a common multicellular mode of growth, where bacteria can be protected against antibiotics and the immune system during infection. This thesis explores molecular mechanisms connecting biofilm formation, motility, and virulence in B. cereus group bacteria, which are all important for the bacteria to cause disease. High levels of the signaling molecule c-di-GMP inside the cell were related to increased biofilm formation and reduced motility and virulence, producing the first description of a c-di-GMP regulatory network in the B. cereus group. The protein CdgL, carrying a tentative domain for c-di-GMP binding, was found to be essential for the cells to produce flagella and perform swimming motility. The DNA-binding regulator protein MogR was found to directly repress the activity of motility genes and also affected the activity of genes related to virulence and biofilm formation. Taken together, this study expands the knowledge of how bacteria coordinate the regulation of cellular movement, biofilm formation, and virulence.
List of papers
|Paper 1: Cyclic diguanylate regulation of Bacillus cereus group biofilm formation. Annette Fagerlund, Veronika Smith, Åsmund K. Røhr, Toril Lindbäck, Marthe P. Parmer, Kristoffer K. Andersson, Leon Reubsaet, Ole Andreas Økstad. Mol Microbiol. 2016, 101(3):471-94. doi: 10.1111/mmi.13405. Epub 2016 Jun 2. The article is included in the thesis. Also available at: https://doi.org/10.1111/mmi.13405|
|Paper 2: MogR is a ubiquitous transcriptional repressor affecting motility, biofilm formation and virulence in the Bacillus cereus group. Veronika Smith, Malin Josefsen, Toril Lindbäck, Ida K. Hegna, Sarah Finke, Nicolas J. Tourasse, Christina Nielsen-LeRoux, Ole Andreas Økstad, Annette Fagerlund. Revised version accepted in Front. Microbiol. 2020, 11: 610650. doi: 10.3389/fmicb.2020.610650. The article is included in the thesis. Also available at: https://doi.org/10.3389/fmicb.2020.610650|
|Paper 3: CdgL is a degenerate GGDEF domain protein affecting flagellin synthesis and motility in Bacillus thuringiensis. Veronika Smith, Ida Kristine Bu Nilssen, Ida K. Hegna, Bjørn Dalhus, Annette Fagerlund, Ole Andreas Økstad. In revision, Research in Microbiology. To be published. The paper is not available in DUO awaiting publishing.|