The mixture of microbes, called bacteriophages, can combat Listeria monocytogenes, which can result in serious infections. The viruses are designed to be sprayed on meat and poultry right before they are packaged.
The bacterium they target can lead to listeriosis, an infection found mostly in pregnant women, newborns and adults with compromised immune systems.
The Centers for Disease Control and Prevention (CDC) estimates 2,500 people become seriously ill with listeriosis each year. Out of that number, 500 die.
The FDA says bacteriophages is designed so that it only attacks strains of the Listeria bacterium and not human or plant cells.
The viruses are grown in a preparation of Listeria monocytogenes, and then purified. The FDA was initially concerned the preparation could contain toxic residues, but testing did not show any presence of residues.
Humans do not come into contact with phages in nature, because they are found in our digestive tracts.
