Blood Test Helps Identify Pigs Shedding Salmonella

by 5m Editor
29 March 2011, at 12:00am

A team from Iowa State University (ISU) is using a blood test to identify level of Salmonella shedding in pigs, according to Melea Reicks Licht of ISU writing in the latest newsletter from the Food Safety Consortium.

In an effort to improve animal health and food safety, Chris Tuggle and colleagues at Iowa State University are finding new ways to identify animals harbouring Salmonella.

"We are developing a blood test to identify animals that shed the least amount of Salmonella into the environment," Professor Tuggle said.

Chris Tuggle

Pigs can contract and carry Salmonella without showing any symptoms. Infected animals shed the bacteria in their manure, which often is used to fertilise crops.

Professor Tuggle, professor of animal science, and his research team examine the genetic make-up of pigs and sample blood and fecal matter for evidence of Salmonella. Then they look for relationships between the expression of genes in blood and the level of Salmonella shed by the pig.

Their findings have identified a gene expression signature, or classifier, that can predict the level to which an animal will carry or methods or manipulation of the guilty genes.

"Salmonella is present in more than half of US swine herds. It results in more than $100 million in annual production losses," Professor Tuggle said. "But more importantly, what’s driving this research is the food safety issue. There are 1.4 million cases of salmonellosis in US annually. Our results have the potential to not only decrease Salmonella contamination in pork, but also on sprouts, peppers or any other vegetable crop for which manure is used as fertiliser."

Preventing the occurrence or spread of Salmonella in swine herds through genetic selection is also a way to use less antibiotics in pork – addressing new regulations, consumer trends and decreased antibiotic effectiveness.

"It takes a collaborative effort to approach this," says Professor Tuggle. "I work with animal scientists, statisticians, computer scientists and immunologists."

March 2011