Opportunism and pathogenicity of Enterococci
OPPORTUNISM AND PATHOGENICITY OF ENTEROCOCCI
Enterococcus faecalis is an ambivalent species, whose members are classified as commensal, food or clinical strains, depending on the isolate. Our research addresses two issues:
- The first research project consists of a comparative analysis of clinical, food and commensal isolates, by a semi-global genomic approach. Our goals:
- Genetic imprint of Enterococcal factors of opportunism: We are comparing genomic profiles using a DNA membrane spotted with 500 genes selected for putative opportunism factors, such as adhesins, toxins, surface proteins, secreted proteins, stress proteins, and regulators. Factors specifically associated with clinical species will be earmarked.
- Comparison of expression levels of genes associated with opportunism in clinical and food isolates, grown in different experimental conditions. In particular, we will examine genes present in isolates regardless of their origins (e.g., those encoding surface proteases), but that are reportedly involved in virulence.
- The second research project is aimed at understanding the genetic basis of E. faecalis colonisation and pathogenicity, using Caenorhabditis elegans and mice as models, and has two goals:
- Identify potential virulmence factors by screening a random E. faecalis mutant library on C. elegans , and then on mice
- Characterize relevant mutated genes
- Study roles of these genes in digestive tract colonisation and in pathogenicity, on a rodent model.
We expect that these analyses of E. faecalis virulence factors will promote a better understanding of colonisation and virulence mechanisms of this ambivalent bacterium.
- PNRA-2006 Flore - QPS : Prospective study to control emergence of new strains in food and better define "QPS" concept. Coordinator Pierre Renault, INRA Jouy en Josas
- Pathogenomics (ERA-NET, transnational program) : Large scale screening of potential key factors involved in the commensalism/virulence transition of Enterococcus faecalis.
- Agence Française de Sécurité Sanitaire de l'Environnement et du Travail (AFSSET)
- Fondation pour la Recherche Médicale (FRM)
05 February 2008
18 April 2008
Pascale Serror : 0033.1.34.65.21.66