<OL> <LI> To mutate the LPS-0-chain polymerase (wzy) to examine polymerase activity <LI> To see how different wzy mutants interact with wzz and change O-chain length <LI> To sequence and mutate oafR, which is a glucosylating enzyme that modifies LPS <LI> To make mutants in the core region of LPS to generate phage type variation without decreasing cell survival or O-chain polymerization. </OL>
Salmonella Enteritidis is most often contracted by consumption of contaminated eggs and certain lipopolysaccharide (LPS) structures correlate with the ability of some strains of S. Enteritidis to more efficiently contaminate eggs. These unusual LPS structures appear to adapt S. Enteritidis to the reproductive tract of hens. The approach for research will be to produce mutants in key LPS genes and to characterize the LPS produced by gel electrophoresis and gas chromatography. Mutants will be mad available to the in-house CRIS for challenge of birds and histopathology. This work is important because little is known about virulence factors that enhance egg-contamination specifically. These objectives support, but do not duplicate, in-house research of USDA that investigates microbial pathogenicity of S. Enteritidis in egg-laying hens.