Major pathogens Staphylococcus aureus, Streptococcus agalactiae, and Campylobacter can all colonize and infect humans and livestock. These species also contaminate food matrices, which can be reservoirs of host infection. Antibiotic resistance increases the risks of treatment failure. Our goals are to:
To address the problems of adaptation, control and resistance to antibiotics, we are developing 3 areas of research on Infection, Detection, and Elimination of Firmicute pathogens.
Pathogen/opportunist bacteria generally share their environments with other organisms. These organisms can then exert control over how well the pathogen persists and survives. For example, commensal bacteria can release molecules important for host niche colonization, or even for virulence. We aim to understand how Streptococcus agalactiae interacts with other organisms, such as Escherichia coli, to recover menaquinones. These redox compounds allow S. agalactiae to shift towards a respiratory metabolism, which is important for its virulence.
Figure 1: A pathogen/opportunist generally shares its environment with other organisms. These organisms can then exert control over the pathogen’s persistence. They can release molecules important for niche colonization, and/or even for virulence. We are trying to understand how Streptococcus agalactiae interacts with other organisms, such as Escherichia coli, to recover quinones.
Mechanisms underlying the use of lipids by bacteria and consequences on antibiotic efficacy.
Many bacteria encode all the functions to synthesize their own membranes. Nevertheless, Firmicutes (and other bacteria) use exogenous lipids as fatty acid (FA) sources, allowing them to bypass the energetically costly steps of FA synthesis. We study the processes involved in lipid incorporation and the consequences on bacterial fitness. Our studies are applied to formulation of synergistic antibiotics to block bacteria that use exogenous FAs for growth.
We develop innovative strategies to limit the spread of bacterial pathogens by creating advanced biosensors for their detection. We mainly focus on development/optimization of sensing elements (DNA probes, aptamers, antibodies, enzymes) that recognize bacterial biomarkers and cutting-edge immobilization strategies for biomolecules, including chemical grafting, affinity interactions or formation of host-microbe interactions. Besides the elaboration of novel biosensors for bacterial detection, the team is experienced in discovery of new biomarkers of bacterial fitness and communication factors (quinone, bacterial extracellular vesicles).
Carbon-screen printed electrode modification and enzymatic sensor construction: the electrode was modified by drop casting with quinone reductase. The detection of quinone was performed in solution containing NADPH as an electron donor, and riboflavin.
All the team publications are available in the MICROBADAPT-MICALIS HAL collection.
