Description du projet
Étudier les réponses bactériennes au stress au niveau monocellulaire
Lors d’une infection bactérienne, notre corps élève sa température en guise de mécanisme de défense, ce qui induit un choc thermique chez les bactéries et aboutit à leur élimination. Les bactéries ont toutefois développé des mécanismes leur permettant de s’adapter à ces nouvelles conditions ambiantes. L’objectif du projet BARTAS, soutenu par le programme Actions Marie Skłodowska-Curie (MSCA), consiste à comprendre comment les bactéries répondent à des stress tels que les changements de température ou les antibiotiques au niveau monocellulaire. Les chercheurs mettront au point une approche basée sur la microfluidique afin de contrôler les conditions de stress et de suivre les réponses bactériennes à l’aide de techniques d’imagerie. Les résultats fourniront des informations essentielles concernant l’impact combiné du choc thermique et des antibiotiques sur la viabilité des bactéries.
Objectif
Antibiotic resistance is one of the biggest scientific and health challenges of our time. If actions are not taken, antibiotics resistance infections will become the first cause of death by 2050. One of the most common signs of bacterial infection is a rapid increase of the host temperature that exposes bacteria to a heat shock (HS). To survive and quickly adapt to this new environment, bacteria activate the synthesis of specific proteins, called heat shock proteins (HSPs). In E.coli HSPs expression is mediated by the alternative sigma factor sigma32 (Sig32). The molecular processes that are associated with the bacterial stress responses induced by a combination of change in temperature and presence of antibiotics have not yet been investigated in detail due to the technical challenges of monitoring this combination of stresses with the necessary temporal and spatial accuracy. Cell-to-cell fluctuations in protein expression could affect single cells survival. Therefore, these processes should be studied with single cell precision. I propose to investigate bacterial responses to the combined stresses of temperature increase and antibiotics at single cell level in live E.coli using a combination of microfluidics and single molecule/super-resolution imaging. I will design and build a microfluid system able to control the stress landscape of temperature and antibiotic concentrations. This will allow me to study Sig32 expression during HS using fast-maturating fluorescent protein fusions. Next, I will monitor how HS affects proteins synthesis by measuring the diffusion changes of single ribosomal subunits (S30 and S50) during HS, using single particle tracking PALM. Finally, I will quantify the interplay between HS response and antibiotic susceptibility by monitoring Sig32 levels and the diffusion of ribosomal subunits. Taken together my results will provide for the first time a quantitative picture and a new framework to study bacterial response to multiple stresses.
Champ scientifique
- natural sciencesphysical sciencesclassical mechanicsfluid mechanicsmicrofluidics
- natural sciencesbiological sciencesmicrobiologybacteriology
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteins
- medical and health sciencesbasic medicinepharmacology and pharmacypharmaceutical drugsantibiotics
- medical and health sciencesbasic medicinepharmacology and pharmacydrug resistanceantibiotic resistance
Mots‑clés
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Régime de financement
HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European FellowshipsCoordinateur
91128 Palaiseau Cedex
France