Natural Bacteriophage May Lower Salmonella Incidence

Bacteriophages, viruses that are found in nature that can kill bacteria, including salmonella, may hold the key to solving one of the most common causes of foodborne illness in humans and that can also affect swine production efficiency.

Generic phages were found to be fairly widely distributed in commercial swine, but only six out of 360 commercial pigs were positive for anti-salmonella bacteriophage.

When these phage were inserted into pigs that were artificially infected with salmonella, the salmonella populations in phage-treated pigs were lower compared to untreated controls, according to studies at the U.S. Department of Agriculture’s (USDA) Agriculture Research Service (ARS).

There were also fewer pigs infected by salmonella in the cecum (at the large intestine) in the phage-treated groups.

“While we do not suggest that we have a complete solution for salmonella, our data indicates that the concept of using phage to reduce salmonella in swine is valid and feasible,” says Todd R. Callaway of Texas A&M University.

“We are continuing to examine commercial swine to obtain more potent anti-salmonella phage to be able to maximize this potential pathogen reduction strategy,” he adds.

The research is being funded by the National Pork Board.

Researcher: Todd R. Callaway, USDA, ARS, Southern Plains Agricultural Research Center at College Station, TX. Contact by phone (979) 260-9374, fax (979) 260-9332 or e-mail