Canada detects new drug-resistant superbug - MCR-1

[Gert van der Hoek]

‘Disturbing’ drug-resistant superbug gene has been detected in Canada

The alarming drug-resistance gene MCR-1 that was first detected in China in November has been found in meat sold in Ontario in 2010, the Star has learned. The gene grants bacteria like E. coli resistance to colistin, a powerful antibiotic of last resort.

Tue Jan 05 2016

An alarming new superbug gene that makes bacteria resistant to a last-resort antibiotic has been detected in Canada, the Star has learned.

The gene, called MCR-1, produces an enzyme that makes bacteria invincible to colistin, a highly-toxic antibiotic used only when all other drugs have failed.

MCR-1 was first reported in November by scientists in China, who published a paper in The Lancet that set off alarm bells across the globe. Analyzing bacterial samples in southeastern China, researchers found 260 samples of E. coli with the MCR-1 gene on meat, hospital patients and farm animals — the likely source of this new superbug, the paper suggests.

But the news that really sent a shudder through the scientific community was that MCR-1 is located on a plasmid — a free-floating snippet of DNA that bacteria can easily share, thus spreading the resistance to other organisms.

The superbug gene was found in three different samples of E. coli, all previously collected for special research projects: one from a 62-year-old patient in Ottawa and two from ground beef sold in Ontario.

The Ottawa patient likely picked up the bug in Egypt, where she lived for several years, according to Dr. Baldwin Toye with the Ottawa hospital, who co-wrote a 2013 paper describing her case and four others.

She was hospitalized three days after moving back to Canada and treated for an abdominal infection. Toye believes another pathogen was responsible for her illness, however, and the patient was simply harbouring the MCR-1 gene, which Mulvey discovered retrospectively during his recent investigation.

Meanwhile, the ground beef samples were found nearly a year apart in different locations in Ontario, a butcher shop and a grocery chain, according to Mulvey. Both were collected in 2010 — predating the samples from China, which were collected between 2011 and 2014.