1. Use the Salmonella Enteritidis (SE) SNP database to link specific genes and regulatory circuits to phenotypes associated with egg contamination, virulence, pathogenicity, host preference, or environmental persistence of subpopulations. 2. Determine whether recurring subsets or patterns of SE SNPs can be identified that are causally linked to outbreak potential of other Salmonella serotypes, and determine if SNPs can be used for risk profiling and cluster detection. 3. Apply information about genomic variation occurring across Salmonella enterica to improve serotyping schemes and vaccines that can be used to develop rapid and sensitive diagnostic and epidemiological testing methodologies for SE in poultry flocks and eggs.