Mcr-1: the potentially untreatable superbug being passed from dogs to owners

New research suggests that dogs infect their owners with a superbug that could become resistance to the ultimate antibiotic, colistin.

The Telegraph reports that scientists are warning of a possible “nightmare scenario” after discovering that the mcr-1 gene can be passed on to humans through “bedding with dogs.” The gene “is housed in the intestine and is transported via microscopic feces, which also makes dog baskets an increased risk area,” the newspaper said.

Researchers at the University of Lisbon took fecal samples from 126 healthy people from a total of 80 households who lived with 102 cats and dogs. Over a period of two years through February 2020, eight dogs and four people were found to be carrying mcr-1.

And the mcr-1 gene has been found in both the dog and the owner in two households, according to the scientists, who presented their results this weekend at the online conference of the European Congress on Clinical Microbiology and Infectious Diseases.

The gene, which was first reported in China in 2015, “confers resistance to colistin, a last resort antibiotic used to treat infections caused by some bacteria that are resistant to all other antibiotics,” says Medical Xpress. “The nightmare scenario that could emerge is that mcr-1 will combine with already drug-resistant bacteria to create a truly untreatable infection,” continues the health news site.

For years, experts have warned that excessive use of colistin, particularly in meat-producing animals, “risks increasing mutated genes” that could “render the drug useless to humans,” reports The Telegraph.

“Colistin is used when all other antibiotics have failed, it’s a critical last resort,” said Dr. Juliana Menezes, who led the research. “If bacteria, which are resistant to all drugs, acquire this resistance gene, they would be incurable, and that is a scenario that we must avoid at all costs.

“We know that the excessive use of antibiotics promotes resistance and that responsible use is of crucial importance not only in medicine, but also in veterinary medicine and agriculture.”

Agricultural antibiotic use is believed to fuel a “growing antimicrobial resistance crisis” that is killing an estimated 700,000 people each year worldwide – and which “is projected to die 10 million a year by 2050 if left unchecked “Says The Telegraph.

To counteract the threat, the EU will ban the “routine preventive” use of antibiotics in livestock from next year, as the Financial Times reported earlier this year. China has banned the use of colistin in animal feed since 2017, and the US has also introduced regulations to reduce antibiotic use.