Scientists believe they have found the first transmission of MCR-1-harbouring Escherichia coli between companion animals and humans.
The MCR-1 gene, which is resistant to “last resort” antibiotics such as colistin, is understood to have been transmitted from dogs to a pet shop worker in China.
Two other patients who shared the same hospital room with the man also tested positive for MCR-1. It is not known if those patients had any further links with the pet shop.
The discovery of an apparent transfer mechanism from pets to humans “adds a new level of complexity” to the growing challenge of plasmid-mediated colistin resistance and raises fresh concerns for pet owners and vets. Previously, MCR-1 had only been found in food animals and humans.
The 50-year-old male shop worker had been admitted to a urology ward of a hospital in Guangzhou, China, suffering with glomerulonephritis. Tests identified E coli isolate EC07 in his urine.
Two other male patients – a 48-year-old with prostatitis and an 80-year-old with bladder cancer who shared the same hospital room with the shop worker – both subsequently tested positive for MCR-1-harbouring E coli.
In a letter published in the September 2016 issue of Emerging Infectious Diseases, the authors stated: “Review of medical records identified the patient carrying E coli isolate EC07 as a worker at a pet shop. In light of this finding, we collected a total of 53 faecal samples from 39 dogs and 14 cats in the pet shop where the man worked.”
The report said scientists found six samples – four from dogs and two from cats – were positive for MCR-1 by PCR and sequencing. All six isolates were resistant to colistin, polymyxin B, cephalosporin, gentamicin and ciprofloxacin.
“These findings suggest MCR-1-producing E coli can colonise companion animals and be transferred between companion animals and humans. The findings also suggest, in addition to food animals and humans, companion animals can serve as a reservoir of colistin-resistant E coli, adding another layer of complexity to the rapidly evolving epidemiology of plasmid-mediated colistin resistance in the community.”
- Read the 5 September issue of Veterinary Times for further reaction.