Scientists at the University of Minnesota have discovered that a single swine vaccine can control both a problematic swine pathogen Lawsonia intracellularis (L. intracellularis) and a harmful human pathogen Salmonella. L. intracellularis causes a disease called “proliferative enteropathy” in swine, characterized by decreased weight post-weaning and diarrhea. Salmonella is linked to over a million human cases of illness in the United States, of which about 10 percent are associated with pork and pork products.
A new study suggests that the vaccination against Lawsonia reduced shedding of Salmonella. It is unclear why this occurs. It is almost certain that the anti-Lawsonia vaccine is not directly responsible for the reduced shedding of Salmonella, however, the vaccine did change the composition of the gut microbiome. The scientists hypothesize that these changes in the microbiome composition led to a reduction in Salmonella. While vaccines that target Salmonella directly are available on the market, this approach offers certain advantages: microbiome manipulations with anti-Lawsonia vaccine can protect against a diversity of Salmonella strains and is a cost-effective practice that is already in place on many farms. This study again confirms a well-established notion that vaccines are an effective way to control most pathogens, with some vaccines offering unexpected "two-for-one" benefits.
NIFA supports this project through the Agriculture and Food Research Initiative.
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