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One food-Borne bacterium that is especially capable of contaminating the contents of eggs is Salmonella enterica serovar Enteritidis (SE). It has been shown that certain strains of SE enter an accelerated phase of growth when environmental conditions provide appropriate signals to the bacterial cell. During enhanced growth, many of the cell surface features of SE alter drastically, which contribute collectively to an enhanced ability of the bacteria to grow to high numbers in organs, as measured by increased recovery from the organs of chicks, mice, and eggs. The most prominent molecule composing the outer membrane of SE is lipopolysaccharide (LPS). Previous research indicated that changes in LPS structure can be used to detect strains that are more capable of attaining full virulence. Current research to be conducted under this grant is directed towards understanding the genetic changes that result in strain variation, as measured by the ability of strains to generate particular LPS structures while maintaining accelerated growth. This work is important because it will lead to a better understanding of environmental conditions that favor outgrowth of new strains of SE.
Bacteria that contaminate food are genetically capable of altering their growth and cell surface properties in order to infect susceptible people or animals. One food-Borne bacterium that is especially capable of contaminating the contents of eggs is Salmonella enterica serovar Enteritidis (SE). It has been shown that certain strains of SE enter an accelerated phase of growth when environmental conditions provide appropriate signals to the bacterial cell. During enhanced growth, many of the cell surface features of SE alter drastically, which contribute collectively to an enhanced ability of the bacteria to grow to high numbers in organs, as measured by increased recovery from the organs of chicks, mice, and eggs. The most prominent molecule composing the outer membrane of SE is lipopolysaccharide (LPS). Previous research indicated that changes in LPS structure can be used to detect strains that are more capable of attaining full virulence. Current research to be conducted under this grant is directed towards understanding the genetic changes that result in strain variation, as measured by the ability of strains to generate particular LPS structures while maintaining accelerated growth. This work is important because it will lead to a better understanding of environmental conditions that favor outgrowth of new strains of SE. Since certain LPS structures alter the production of proteins on the cell surface, this research should also contribute to a more complete understanding of the immunological properties of virulent SE and to the development of improved vaccines.