research

Our laboratory, entitled "Ecology and evolution of microorganisms", belongs to the French Institute for Medical Research (Inserm) and is located at the Xavier Bichat medical school (Paris 7 university) in the north of Paris. Created in January 2003, with a developing team led since the beginning of the 1990's by Erick Denamur, it has been enriched by young scientists of diverse backgrounds.

The goal of the lab is to bring fundamental evolutionary approach in research on infectious diseases. The purpose of our research is to achieve a better understanding of the ecological and evolutionary parameters allowing the adaptation of microorganisms, especially those involved in the emergence of virulence and antimicrobial resistance.

Despite a century of often successful prevention and control efforts, infectious diseases remain an important problem in public health, causing over 13 million deaths each year. New diseases emerge, previously controlled diseases re-emerge, and antimicrobial drugs resistance increase. Two main causes explain these observations: changes associated with the evolution of human societies over the last century and the constant ability of microorganisms to evolve and adapt.

The adaptation of populations relies on the generation of genetic diversity and on the action of natural selection. Among the mutants randomly generated, natural selection retains the fittest individuals, i.e., those that are more prone to survive and reproduce in their environment. Although numerous works have investigated the molecular aspects of microbial virulence and resistance, few studies have focused on the evolutionary origins and consequences of this virulence and resistance.

Two aspects are essential for the understanding of the evolution of microorganisms: (i) the adequation between their genome and the environment and (ii) the constraints acting on their mode of adaptation. To gain further insights into these issues, we have chosen to work on Escherichia coli (laboratory and natural isolates) and the bacteriophages phiX174 and phi6. Our multidisciplinary approach brings together genetics, biochemistry, molecular biology, molecular evolution, phylogeny, experimental evolution, modelisation, ecology and clinical research. Our team is composed of a variety of researchers including mathematicians, evolutionists, pharmacists and medical doctors.

Our research is at the interface of fundamental and clinical research. The identification of parameters involved in the adaptation of microorganisms will allow us to give some inferences on modes of adaptation, speciation, and epitasis between the different regions of the genome, as well as to provide medical applications in public health, such as new preventative or anti-infectious therapeutic strategies.