Simon Baeriswyl et al. (2007) International Worm Meeting "How intestinal bacteria shape the mortality profiles of the nematode C. elegans."

Ivan Matic, Thomas Mosser, Mederic Diard, Francois Taddei, Simon Baeriswyl

[International Worm Meeting, 2007]

Caenorhabditis elegans has proven for many years to be a versatile model for the study of aging and of evolutionarily conserved mechanisms of microbial pathogenesis, among other reasons due to its translucency. The object of my study is the impact of feeding different pathogenic and non-pathogenic Escherichia coli bacteria to C. elegans on the mortality rates of the latter, with particular consideration of late life plateaus (aging deceleration at the population level). I establish kinetics of bacterial proliferation within the worm digestive tract as well as lifespan measurements using killed, fluorescent or knock-out-mutation carrying bacteria.

Mederic J. Diard et al. (2007) International Worm Meeting "Caenorhabditis elegans as a simple model to study phenotypic and genetic virulence determinants of extraintestinal pathogenic Escherichia coli."

Stephanie Gouriou, Erick Denamur, Simon Baeriswyl, Francois Taddei, Mederic J. Diard, Olivier Clermont, Bertrand Picard, Ivan Matic

[International Worm Meeting, 2007]

Extraintestinal pathogenic Escherichia coli (ExPEC) strains cause disease by invading normally sterile niches within the host body, e.g., urinary tract, blood and cerebrospinal fluid. Infections due to ExPEC strains, in particular urinary tract infections, cause considerable morbidity and significant health-care costs. The goal of our study is to evaluate whether Caenorhabditis elegans can be used as a model to study phenotypic and genetic virulence determinants of ExPEC strains. For this purpose, we used a collection of 31 E. coli strains isolated during acute extra-intestinal infections or from the feces of healthy individuals. For all strains, the phylogeny, the presence of ExPEC virulence factors, the resistance to biologically relevant stressors (bile, human serum and lysozyme), the motility, the growth rate, the virulence in C. elegans and in a murine septicaemia model has been established. The results show that there is a strong link between virulence in C. elegans and certain phenotypic and genetic virulence predictors of ExPEC strains determinable in vitro. Furthermore, there is a significant correlation between virulence of different ExPEC strains in C. elegans and in the murine model. Therefore, our results suggest that C. elegans can be used as a model to study virulence determinants of ExPEC strains.