CategoryPre-Harvest Pork Safety
Date Full Report Received02/01/2007
Date Abstract Report Received09/09/2008
InvestigationInstitution: National Animal Disease Center, USDA-ARS
Primary Investigator: Shawn Bearson
Co-Investigators: Jack C.M. Dekkers, Jolita Uthe, Yanfang Wang, Long Ou, Dan Nettleton, Christopher Tuggle
Funded ByNational Pork Board
Pigs that shed Salmonella in their feces are an animal health issue, a food safety problem and an environmental contamination risk. Our research program investigates the undesirable carrier state of Salmonella in pigs in order to identify approaches to control both clinical and sub-clinical (carrier) infections. Our research has identified pig genes that respond to infection with Salmonella. A DNA sequence variation was identified in one of the Salmonella-response genes (CCT7). When we compared the sequence of the CCT7 gene with the Salmonella shedding status of 40 infected pigs, we found that pigs with a specific DNA sequence were less likely to shed Salmonella in their feces than pigs with a different DNA sequence. Thus, pigs with this specific DNA sequence may be more resistant to infection with Salmonella. Furthermore, the amount of a specific immune compound (interferon-?) in the blood of the infected pigs also correlated the Salmonella shedding status of the pigs as well as specific blood cells that fight infection. Identifying factors in the pig that control the ability of the animal to combat disease will uncover markers for classifying potential carrier pigs as well as targets for disease diagnosis, intervention and prevention.