Poultry antibiotics may fuel human resistance - study
Canadian research links ionophores to rising AMR risk
26 June 2025
2 minute read
By: A new study, published in mSphere, a journal of the American Society for Microbiology, suggests some antibiotics used in conventional poultry farming may contribute to the development of antibiotic resistance in humans, according to a press release from Perdue Farms. This research, conducted by Alex Wong, Asalia Ibrahim and Jason Au of Carleton University’s Department of Biology, focuses on ionophores, a class of antibiotics commonly used in conventional poultry farming and previously described as “not important to human medicine.”
“This research underscores the importance of understanding the interconnectedness of animal and human health,” said Wong. “While ionophores have long been considered safe for use in poultry to prevent parasitic infections, this study suggests that ionophore use could fuel the growth of antibiotic resistance to medically relevant drugs.”
This study highlights the ongoing research and critical discussion about responsible antibiotic use in animal agriculture, showcasing the potentially negative long-term human and animal health effects of using antibiotics in animal production, even those not presently deemed “important to human medicine."
The study found:
- Bacterial pathogens around the world have genes (narA and narB) that allow them to resist ionophores.
- These genes are often found linked to other resistance genes that protect bacteria from human antibiotics.
- When ionophores are used, they can unintentionally encourage bacteria to carry both types of resistance – making them harder to kill with medicines we need and increasing the risk of clinically significant antimicrobial resistance spreading from animal agriculture to human healthcare systems.
The study’s findings contribute to the ongoing scientific conversation about antibiotic resistance and inform future research and policy decisions and provides evidence that the widespread use of ionophores potentially threaten human health.
“This study surprised me. Personally, I’ve been dismissing the use of ionophores for years because we didn’t have this evidence. This study suggests that it could be driving resistance to the drugs we do care about. When animal producers use ionophores they can drive the growth of bacteria that are resistant to our most important medicines,” Lance Price, M.S. Ph.D., Professor at George Washington’s (GW) Milken Institute School of Public Health and Founding Director of GW’s Antibiotic Resistance Action Center.
Perdue stands firm on ‘no antibiotics ever’ commitment
Ionophore use in poultry has been on the rise after a reintroduction of usage by large producers—with some poultry companies relying on routine use of the drug class for preventing illness. However, Perdue Farms committed to No Antibiotics Ever (NAE) in 2016, stopping the use of all antibiotics including ionophores. The company remains committed to the program.
“We started our NAE transition initially due to consumer demand, however with time we have seen, and appreciate, the animal welfare and human health benefits of this approach,” said Bruce Stewart-Brown, DVM, Chief Science Officer at Perdue Farms. “For a decade now, our No Antibiotics Ever commitment has reflected our belief that what’s good for the bird is also good for people– and this study confirms that belief is well-founded. At the end of the day, it’s a promise that gives consumers peace of mind and sets a higher standard for responsible poultry production.”
This research was funded by the Canadian Government, Natural Sciences and Engineering Research Council of Canada (NSERC) and Perdue Farms. Learn more about the study and Perdue Farms’ commitment to NAE at corporate.perduefarms.com.
