The evaluation of genetic and phenotypic diversity in field isolates of Salmonella enterica serovar Enteritidis in Uruguay. (360G-Wellcome-078168_Z_05_Z)

Salmonella Enteritidis causes food-borne disease world-wide. It commonly contaminates the food chain and poultry products are a major source. Particular strains are associated with outbreaks. We have shown that in Uruguay different strains survive in the chicken population, with only a small proportion of them spreading through food to humans. We therefore hypothesize that different strains have different genetic characteristics that give rise to populations able to exploit different ecological niches. We thus propose to undertake comprehensive comparative genomic analyses of Uruguayan field isolates. Molecular typing methods will be used to allow sub-grouping of the strains. Multi-Locus Sequence Typing and microarray analysis will be applied to identify evolutionary trends, population structures, and genetic heterogeneity between strains. The genomes of three individual strains will be sequenced using new high-throughput technology at the Sanger Institute. This population information will inform selection of representative strains for use in in vitro and in vivo assays to assess their capacity to interact with different hosts.This study will provide unique information regarding the relationship between strain variation and the exploitation of different hosts by S. Enteritidis, and may inform the development of intervention measures that may be effective in developing countries.