Project Number: 6612-32000-004-02
Project Type: Nonfunded Cooperative Agreement

Start Date: Jan 14, 2009
End Date: Jan 31, 2011

Objective:
To identify genes that are expressed in the poultry environment as compared to genes that facilitate colonization of the hen and the completion of the infection pathway that results in egg contamination.

Approach:
We will use genomically characterized strains that vary in phenotype to construct cDNA banks so that the breadth of patterns of gene expression that have the potential to impact egg contamination and biofilm formation can be observed. At least three different strains of S. Enteritidis known to vary in genotype and phenotype will be grown under different conditions of temperature and pH. One strain forms biofilm, but does not contaminate eggs. A second strain contaminates eggs, but does not form biofilm. The third strain forms biofilm and contaminates eggs. At stationary phase, total RNA will be isolated from the different cultures. From these samples, mRNA will be enriched and used to construct cDNA banks. Banks of cDNA will be analyzed for the presence/absence of expression by hybridization to Salmonella gene sequences that were previously selected for evidence of undergoing evolution between strains. Other strains will be incorporated according to research results from processing of the initial 3 strains or as needed to provide controls. Mutants of the original three strains will be similarly analyzed for gene expression as they come available. Genes of interest will be mutated by the Datsenko and Wanner suicide vector methodology.