Biology of Gram-positive pathogens

Biology of Gram positive Pathogens Unit

Patrick Trieu-Cuot
Low G+C% Gram positive bacteria are constituted by closely related but phylogenetically, physiologically, and genetically distinct genera (bacilli, clostridia, listeria, staphylococci, streptcocci, and enterococci) which share a common ecology, however, as human parasites. They are considered as leading pathogens causing high morbidity and mortality in humans. In particular, it is estimated that Gram positive cocci (enterococci, streptococci, and staphylococci) produce at least a third of all human bacterial infections, including strep throat (Streptococcus pyogenes), meningitis and pneumonia (Streptococcus pneumoniae and Streptocccus agalactiae), otitis media (S. pneumoniae), food poisoning (Staphylococcus aureus), various skin diseases and severe types of septic shock (S. aureus and S. pyogenes).
The main goals of our research activity aim at elucidating new pathways/mechanisms involved in the pathogenesis of low GC% Gram positive pathogens. We believe that the in-depth understanding of infectious processes will contribute to the development of new therapeutics or innovative tools for the treatment, prevention and control of infections due to Gram positive bacteria.
We have chosen S. aureus and S. agalactiae, as models of extracellular human pathogens and L. monocytogenes as a model human intracellular

Our main research topics are :

• Gene regulation in relation with :
- Stress response
- Environmental adaptation (two-component regulatory systems)
- Expression of virulence

• Bacterial surface components and interaction with the host :
- Lipoteichoic acids
- Cell-wall anchored proteins
- Lipoproteins