Bacteriophages a Possible Alternative to Antibiotics in Animal Production

Agricultural Research Service scientists have found encouraging results with an experimental way to reduce foodborne pathogens and treatvarious poultry diseases. Early success in the laboratory with bacteriophages could open the door to another way of preventing and treating animal disease.

Escherichia coli bacteria cause respiratory disease in poultry, leading to death or condemnation of the carcasses during processing. Bacteriophages are viruses that infect bacteria and can kill them. A particular phage can usually infect only one or a few related species of bacteria.

Scientists at the ARS Poultry Production and Product Safety Research Unit, Fayetteville, Ark., isolated a number of bacteriophages that would target a particular strain of E. coli that causes disease in poultry, according to William E. Huff, a poultry physiologist at the Fayetteville lab. They used E. coli serotype 02 to cause an air sac infection, called air saculitis, in broiler chickens. When a bacteriophage was mixed with the E. coli strain prior to challenging broiler chickens with the bacteria, the scientists were able to completely protect the animals from respiratory infection.

Researchers chose air saculitis because it is very difficult to treat, according to Huff. There may be other bacteriophage strains that are better suited to attack the bacteria they used in their experiments, he added.

Bacteriophages were first discovered in 1915, but research on their therapeutic use was largely abandoned outside of Eastern Europe when antibiotic drugs became widely available in the 1940s.

The ARS researchers recently began their next step to investigate the effectiveness of the phages to not only prevent but to treat an infection in poultry. This research offers the possibility that bacteriophages could be developed as an alternative to antibiotic use in poultry production, according to Huff. He is also investigating the efficacy of bacteriophages against other foodborne pathogens, such as Salmonella and Campylobacter. He has isolated bacteriophages to Salmonella in cooperation with the University of Arkansas.

ARS is the U.S. Department of Agriculture’s chief scientific research agency.