Treating meat and produce with selected types of bacteria-killing viruses could significantly reduce concentrations of E. coli pathogens, according to a Purdue University study.

In trials, an injection of bacteriophages, also known as “phages,” nearly eradicated a toxin-producing strain of E. coli in spinach and ground beef, according to a news release. In some cases, it reduced E. coli concentrations by up to 99%.

Researchers tap bacteria-killing viruses to fight E. coliThe research involved the E. coli O157:H7 strain, one of the most virulent. Ingesting just 10 colony-forming units of the pathogen can cause serious illness, according to the release.

Based on the results, researchers at the West Lafayette, Ind.-based university said the phage treatment could be an effective tool to help ensure the safety of food.

“Phage treatment is a way of harnessing the natural antibacterial properties of phages to limit E. coli and other important foodborne pathogens,” Paul Ebner, associate professor of animal sciences and lead researcher, said in the release. “Applying this kind of therapy to contaminated foods will make them safer.”

The researchers intentionally infected fresh spinach leaves and ground beef with 10 million E. coli cells, an amount far greater than typically found in contaminated food.

They then treated the food with a phage cocktail — a liquid containing three different kinds of phages.

After 24 hours, the treatment had reduced E. coli concentrations in the spinach, stored at room temperature, by more than 99.9%. Pathogen levels dropped by more than 99.8% and about 99.8% in spinach after 48 and 72 hours, respectively.

“Bacteria have viruses just like we do,” Ebner said in the release. “We’re taking what already exists in nature and concentrating it to have an impact on these bacteria.”

The phages pose no threat to human health because they are highly host-specific and only target certain types of bacteria, according to the release.