The main goals of our research activity aim at elucidating new pathways/mechanisms involved in the pathogenesis of low GC % Gram-positive bacteria that constitute a major burden for public health. We believe that in-depth understanding of infectious processes can contribute effectively to the development of new therapeutics or innovative tools for the treatment, prevention and control of these infections.
We have chosen Staphylococcus aureus and Streptococcus agalactiae (also known as Group B Streptococcus) as extracellular model organisms. A new line of research has opened on Streptococcus gallolyticus.
Both S. aureus and S. agalactiae are present as commensal bacteria in humans. Our main goal is to identify and characterize the conditions required for these bacteria to become pathogenic. In other words, we aim to understand the molecular bases underlying the transition between bacterial commensalism and pathogenicity. Collaboration with the National Reference Center for Streptococci is particularly important to get relevant and contemporary clinical strains.
Our main research topics are:
• Gene regulation in relation with:
– Stress responses
– metabolic adaptation to environment (pH, temperature, host components such as serum, fatty acids, antibiotics, , etc…)
– Expression of virulence
• Bacterial surface components and interaction with the host:
– Extracellular polysaccharides (group B carbohydrate and capsule), lipoteichoic and teichoic acids
– Secreted and cell-wall anchored proteins including covalent pili polymers
• Comparative streptococcal genomics to understand bacterial evolution and rise of antibiotic resistance but also to identify new genes involved in pathogenicity