Using and talking about evidence correctly is important. Ionophores are not antibiotics

As a BBC program causes quite a stir in the UK, a feed industry expert says he does not believe that there is any real-world evidence to suggest that the use of ionophores will lead to issues with increased resistance to antibiotics of medical importance.

There has been a huge UK media response to the BBC’s Countryfile program on the use of ionophore coccidiostats in the poultry meat sector there; the program was broadcast on Sunday March 31.

Countryfile claimed there is “a hidden mountain of antimicrobial drugs​” still being used on many of UK’s chicken farms that are not the AMR hit list but that operate in a very similar way to antibiotics. It was, of course, referring to ionophores. The program heard from campaigners concerned that such drugs could pose a threat to human health and the environment.

But Dr Richard Murphy, director of research, Alltech, told FeedNavigator:

“Extensive research over the years hasn’t really found a link between ionophore use and issues associated with increased antibiotic resistance to antimicrobials used for human medical use. ​

“It’s important to note that ionophores are not used for human medical purposes and tend to have different modes of action to the antibiotics used in human medicine. ​

“While resistance to ionophores has been demonstrated in rumen microflora, the mechanisms by which this occurs is different to those for classically considered antibiotics and there is little evidence that ionophore resistance can be spread from one bacterium to another.”​

The UK’s chief vet, Christine Middlemiss, tweeted: “Using and talking about evidence correctly is important. Ionophores are not antibiotics.​”​

Unpicking the issues 

And the British Poultry Council also weighed in​​ on the subject, trying to unpick some of the issues raised. It said the recent media coverage on the use of ionophore coccidiostats in poultry shows a lack of clarity around their classification and use.

“We’re committed to upholding UK’s position at the forefront of international efforts to keep antibiotics effective for future generations and tackling antimicrobial resistance (AMR). Suggesting that the sector is hiding a mountain of drugs is speculative and shows lack of clarity around the classification and use of ionophores.​

“We must steer clear of speculations when talking about such an important subject. The World Health Organization (WHO), the World Animal Health Organization (OIE), and the European Surveillance Program of Veterinary Antibiotics have confirmed that ionophores have no impact to human health. The European Food Safety Agency (EFSA) has also scrutinized the use of ionophores and published opinions have deemed them safe to be used as a feed additive with no risk to humans.”​

Rearing conditions ​

Activist Coilin Nunan, from the Alliance to Save our Antibiotics, told the BBC program the group was calling for​​ ionophores to be made prescription-only; they also want chickens to be kept in better conditions so that they don't get exposed to coccidiosis in the first place, he added.

On that point, the British Poultry Council said the parasite is extremely common in all poultry worldwide regardless of how they are kept - indoor-reared, free-range and organic.

“Ionophores are mainly used to control coccidiosis, maintain intestinal integrity, avoid pain and suffering and help deliver good bird health and welfare.”​

While ionophores are not currently used in human medicine, remarked Nunan’s group, several scientific studies​​ have suggested they, or very closely related antibiotics, may have the potential to be effective treatments in the future for the serious, and often lethal infection Clostridium difficile​. “Very few antibiotics are currently available to treat this disease.”​

And that alliance cited a paper produced by the Norwegian government’s Scientific Committee for Food Safety​​, reportedly showing evidence that the use of ionophores in poultry can increase resistance to some antibiotics used in human medicine; further research is required to confirm the finding, they noted. 

'Media misrepresentation' 

Industry organization, Responsible Use of Medicines in Agriculture Alliance (RUMA), also contested the findings of the BBC program. That coalition of animal health and welfare, veterinary, farming and retail groups, said “the misrepresentation of ionophore coccidiostats in the media today is disappointing, not least because of the important and entirely legitimate role coccidiostats play in protecting farm animals and pets at risk of infection from coccidian protozoa parasites.”​

Before ionophores are legally marketed for commercial use in food-producing animals, companies have to demonstrate to the regulator (EFSA) that each product is safe and effective in the target animal species, safe for humans consuming edible products from treated animals, and safe for the environment, said RUMA.

“There is no evidence they create any cross-resistance issues with gram negative bacteria such as E coli or zoonotic pathogens such as campylobacter or salmonella.”​