Regulatory Evolution of Bacterial Virulence – VirEvol

Heterogeneity in microbial virulence is commonly observed between strains of the same species. In clinical settings, this diversity might be associated with the emergence of clones associated with specific pathologies or specific hosts. A major driving force in the diversification of bacterial pathogens is the acquisition of novel virulence genes, either by horizontal gene transfer or through allelic variation. In addition, the evolution of regulatory pathways involved in the control of virulence genes have an important impact on the interactions between the pathogen and the host. This regulatory evolution is well documented between related species but our knowledges on intra-species evolution of regulatory pathways is very limited to date.
Comparative genomics and functional studies in reference strains have been instrumental to decipher the molecular basis of virulence, but we need novel approaches to investigate the heterogeneity of virulence in a bacterial population and to characterize the extent of signalling pathway evolution in the phenotypic diversification of pathogens. This project aims to overcome current limits by a pan-transcriptomic analysis of virulence gene expression in Group B Streptococcus (GBS) and a population-based analysis of virulence in animal models of infection. This project will provide critical insights on the specific and the conserved bacterial mechanisms required during infections, allowing the emergence of clones associated with specific host or diseases.