Dogs and cats are passing antibiotic-resistant ‘superbugs’ to their owners, a new study suggests.
A pet in the UK and several in Portugal have been found to carry antibiotic-resistant bacteria similar to their owners.
These could include E. coli bacteria and another one linked to pneumonia, scientists say.
They are calling for households with pets to be included in programs to curb the spread of antimicrobial resistance, as it reaches dangerously high levels around the world.
Drug-resistant infections kill about 700,000 people a year globally, a number that is expected to rise to 10 million by 2050 if no action is taken, leading the World Health Organization (WHO) to call it one of the biggest public health threats that humanity faces.
It is already known that dogs, cats and other pets contribute to the spread of antibiotic-resistant pathogens that can cause human disease. But until now it was unclear whether infected pets actually share pathogens with their owners.
Stool samples from dogs, cats, and their owners were tested for common antibiotic-resistant Enterobacterales, which include E. coli and Klebsiella pneumoniae.
Experts have focused in particular on the antibiotic-resistant bacteria WHO deems “most important” to human medicine – those used to treat meningitis, pneumonia and sepsis, known as third-generation cephalosporins.
Additionally, they looked for carbapenem-resistant bacteria, used as a last line of defense when all others have failed.
Ms Menezes, a PhD student at the University of Lisbon, said: ‘In this study, we provide evidence that bacteria resistant to third-generation cephalosporins, critically important antibiotics, are transmitted from pets to their owners .
“Dogs and cats can help the spread and persistence of these bacteria in the community and it is vital that they are included in antimicrobial resistance assessments.
“Owners can reduce the spread of multi-resistant bacteria by practicing good hygiene, including washing hands after picking up their dog or cat’s waste and also after petting them.”
The team studied five cats, 38 dogs and 78 humans from 43 households in Portugal. Seven dogs and eight humans from seven families were also collected from the UK.
Of the entire group, three cats, 21 dogs, and 28 owners tested positive for bacteria resistant to the major third-generation cephalosporins.
In eight families, both the pet and the owner carried Enterobacterales. Two were houses with cats, six with dogs
In six of these homes, the DNA of the bacteria in the pet and owner was similar, meaning the disease was likely passed between pets and humans.
It is unclear whether the bacteria were transferred from animals to humans or vice versa.
Of the UK cohort, one dog was colonized with a multi-drug resistant E. coli strain, which fuels the most ‘critically important’ antibiotics, the last line of defense and others.
In Portugal, a dog carrying the same bacterium was found to be resistant only to third generation cephalosporins.
Another Portuguese dog suffered from a strain of E. coli that encourages antibiotic resistance.
All pets have been cared for for their condition. The owners were not sick and left without treatment.
The research will be presented at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Copenhagen, Denmark between 15 and 18 April.