The UK livestock industry has agreed to voluntary restrictions on the use of colistin, a ‘last-line antibiotic’, in response to new evidence of resistance to it in livestock and humans.
The restrictions, which will be in place while an EU risk assessment takes place, will limit colistin use to ‘an antibiotic of last resort’ and to used only after susceptibility testing had shown it was the only effective antibiotic available for treating the sick animals.
The decision was announced by the Responsible Use of Medicines in Agriculture Alliance (RUMA), an alliance of 24 organisations representing ‘farm to fork’, which aims to promote best practice in the use of medicines on farm.
It was made following the publication of a study in China last month, which found high levels of antimicrobial resistance (AMR) to an important antibiotic, colistin, used to treat E.coli on farms and in human patients.
The study reported the resistance was caused by a new gene that makes common bacteria resistant to colistin, prompting fresh warnings the world could be on the brink of a ‘post-antibiotic’ era.
It also and led to calls for a ban on the use of antibiotics in livestock when the same drugs are also used to treat humans.
The EU had called for a revised risk assessment on colistin use in animals.
RUMA secretary general John FitzGerald said the alliance had consulted the veterinary sectors who use colistin, pigs, poultry and cattle, and they had agreed to restrict their use of colistin while the risks were being re-assessed.
He said this was a ‘positive and proportionate response’ particularly as no E Coli colistin resistance in the UK was reported in the latest surveillance results’.
While there are no official figures for colistin use in the UK, RUMA said it was understood ‘less than a tonne each year is used in UK livestock’.
“It is, therefore, difficult to quantify the impact of the proposal but vets will now have new guidance on how to use colistin,” Mr Fitzgerald said.
For example, colistin is being moved from category 2 to category 3 in vets’ antimicrobial prescribing guidance, which means ‘we would expect less colistin to be used’, he added.
The British Veterinary Association (BVA) has called for a proportionate response to the Chinese study.
BVA senior vice-president John Blackwell acknowledged, in light of the evidence, ‘it would be pragmatic to carry out new risk assessments’.
But he added: "Yet this shouldn’t create a reaction that leads to the withdrawal of antibiotic use in animals as it is essential to maintain the health and welfare of both companion and food animals.
"Rather the China study reinforces the need for responsible antibiotic use in both human and animal medicine."