The discovery that a much feared “superbug” gene has somehow crossed the border into Canada is increasing calls for more oversight of on-farm antibiotic and antimicrobial use.
The new gene, called MCR-1, makes bacteria immune to a group of antibiotics used as the last defence to fight resistant bugs. MCR-1 was confirmed to have surfaced in China in November, and that prompted health agencies around the globe to search for it on home soil.
Last month, the Public Health Agency of Canada said it had found the gene present in three cases from among 1,600 reviewed — two involving ground beef in Ontario in 2010 and one involving an Ottawa woman in 2011.
It is a warning that can’t be ignored, said Darrell Dalton, registrar for the Alberta Veterinary Medical Association.
“The livestock and food production industry has to recognize that they are the ones where change has to occur,” said Dalton. “They’re the ones who have to stand up and say, ‘I’m responsible and then use antibiotics responsibly.’
“They’re going to have to say that, and do that. Down the road, I would fully anticipate an audit process to make sure that antibiotics and antimicrobials aren’t making it into feed or foodstuff.”
The big fear — and it’s a terrifying one for health authorities — centres around the fact that MCR-1 is resistant to a group of antibiotics called polymyxins, which includes a drug called colistin. The latter is a drug of last resort when fighting antibiotic-resistant strains of illness caused by resistant bacteria and viruses. Already an estimated 700,000 people die annually from otherwise treatable conditions and losing colistin could see that number soar.
Colistin was never registered for use in Canadian livestock production, said Jean Szkotnicki, president of the Guelph-based Canadian Animal Health Institute.
“The product was never, and isn’t registered in Canada for food animals,” she said. “It doesn’t have much to do with our membership, who all have licensed products.”
Nevertheless, there is evidence that the pharmaceutical ingredient was used in food animal production here.
“In a drafting of early swine producer guidelines, the use of colistin as an active pharmaceutical ingredient was one of the alternatives — it’s been removed, but that indicates that there must (have been) some use,” she said.
It was also given to veal calves, she said, which may explain why the public health agency found it in hamburger samples.
The situation highlights the danger of producers importing drugs under own-use regulations.
“Nobody wants to talk about it (so) it’s hard to know how much antibiotics or antimicrobials is going into the feeds,” said Dalton.
But currently, farmers can “go down (to the U.S.) with an empty trailer and bring back all the antibiotics or pharmaceuticals they want,” he said.
“In some areas — Quebec being one of them — they’re using active pharmaceutical ingredients, said Dalton. “They’re importing them by the barrel and adding them to the feed, but that isn’t registered in Canada, or listed as an antimicrobial. That’s what happened in the colistin case.”
The Alberta Veterinary Medical Association has been trying to raise awareness of resistance and promote responsible antimicrobial use, including recently launching a new website: www.raisedwithcare.ca.
While genotyping is showing there’s “not a lot of similarity between the antibiotics and antimicrobials used in veterinary medicine versus human medicine,” said Dalton, producers need to be doing everything they can to reduce their use. That includes using vaccinations, biosecurity, anti-parasite control, and reducing stress in animals to lower incidence of disease.
Szkotnicki said that although she hasn’t heard any specifics, she expects Health Canada will soon be bringing in new regulations for drug use in livestock.
Some new rules are already on the way.
Next year, all growth promotion claims will be taken off antibiotics and antimicrobials. As well all water solubles and feed additives for medically important antimicrobials will require a veterinarian’s prescription.