|Lowry, Virginia - TEXAS A&M UNIVERSITY|
Submitted to: International Symposium on Epidemiology and Control of Salmonella in Pork
Publication Type: Proceedings
Publication Acceptance Date: August 18, 1999
Publication Date: N/A
Interpretive Summary: The contamination of pork products by pathogens such as Salmonella is a major food safety issue. Public outcry against the use of antibiotics in food animals and the development of multiple antibiotic resistant bacteria have caused researchers to look for alternative ways to combat bacterial infections in these animals. Previous studies in our laboratory addressing Salmonella contamination in poultry led to the development of a Salmonella-immune lymphokine (ILK) that was found to protect neonatal chickens and turkeys from Salmonella infections. Lymphokines are protein substances secreted by white blood cells, which are important mediators of a host's defense against bacterial and viral invaders. The present studies use the idea of immune lymphokine, successfully applied to poultry in this laboratory, and apply this idea to pigs. A pig Salmonella-immune lymphokine (PILK) was made to help pigs fight Salmonella infections. These studies show that PILK protects both newborn and weaned pigs from Salmonella infections and that this protection is most likely achieved by increased white blood cell killing of Salmonella.
Technical Abstract: Salmonella enteritidis-immune lymphokine (ILK) potentiation of the innate immune response in neonatal poultry led to the application of immunopotentiation using immune lymphokines in neonatal and weaned swine. A S. enteritidis-immune lymphokine (PILK) was isolated from the splenic T cells of S. enteritidis-immune pigs. PILK was then administered orally to weaned pigs, considered to possess deficient immune responses, which were subsequently challenged with both lethal and non-lethal doses of the swine pathogen S. choleraesuis (SC). PILK-treated pigs were shown to have a 50-60% decrease in organ invasion and a similar reduction in cecal colonization by SC. PILK also enhanced growth performance in both SC challenged and non-challenged pigs, with PILK-treated pigs gaining an average of 5 pounds more than both non-challenged controls and SC challenged controls. PILK also significantly reduced morbity and mortality as compared to control pigs. Neutrophils isolated from the peripheral blood of PILK-treated pigs exhibited increased functional capabilities when compared to control pigs. Significant increases in the oxidative burst, adherence to nylon wool and bovine serum albumin-coated slides, and increased movement towards chemotactic stimuli were shown by neutrophils from PILK-treated pigs when compared to neutrophils from control pigs. We have shown that PILK protects pigs from SC organ invasion, cecal colonization and enhances growth performance and neutrophil functions in weaned pigs.