Nov. 1, 2006 - Oct. 31, 2009Award Number
USDA - CSREESAmount Awarded
Mark Lawrence, Ph.D.
Mississippi State University-College of Veterinary Medicine
Burgess, S.; Bridges, S.Summary
Listeria monocytogenes is a significant bacterial foodborne pathogen that causes a number of food product recalls in the U.S. each year. However, while many L. monocytogenes strains can cause disease and/or mortality, others have low virulence or are avirulent. The ability to determine the pathogenic potential of L. monocytogenes isolated from food products will enable better prediction of the health risk to consumers. There is evidence that the ability to resist killing by host immune cells (macrophages) is a distinguishing feature between virulent and avirulent L. monocytogenes. We hypothesize that virulent and avirulent L. monocytogenes strains have different protein expression responses to the stressful intracellular environment of host macrophages; this difference is likely one of the contributing factors to the outcome of infection. The immediate objective of this proposal is to conduct a comparison of protein and RNA expression profiles from virulent and avirulent L. monocytogenes strains in response to phagocytosis by mouse macrophages. We expect that this project will result in identification of genes and proteins expressed by virulent L. monocytogenes that are critical in defining the outcome of survival in macrophages and in determining the outcome of infection. These findings will contribute to our basic understanding of the mechanisms of intracellular survival for this important pathogen and will allow the identification of markers for identification of virulent L. monocytogenes.