Pets Can Carry Same 'Superbug' Strains as Owners
But infection tends to originate in humans, so concern that your cat or dog has MRSA isn't necessary, researchers say
By Randy Dotinga
TUESDAY, May 13, 2014 (HealthDay News) -- A new study may provide the best evidence yet that the superbug known as MRSA can travel between humans and their pets, although researchers caution that people shouldn't worry too much about the germ lurking in their cats and dogs.
In the big picture, the findings reveal how the use of antibiotics can affect germs that infect both people and animals, explained study author Ewan Harrison, a research associate with the University of Cambridge in England.
The research also shows how "infectious diseases in humans and animals are intrinsically linked and should be seen as a single problem to be addressed jointly by human and veterinary medicine," he said.
Methicillin-resistant Staphylococcus aureus, better known as MRSA, causes infections in the skin, in the bloodstream and elsewhere in the body.
Once mainly limited to sick people in hospitals and nursing homes, MRSA has spread into the world at large, often infecting healthy people such as prisoners and athletes who share supplies like towels and razors. MRSA can be deadly, and it can't easily be vanquished by antibiotics.
It's no secret that MRSA can travel between species. In one well-known case, a newborn elephant at a zoo died after a human taking care of her accidentally infected her with MRSA.
But while some types of MRSA appear "to be able to transmit easily between different species, others seem to be restricted to one or a small number of animal species, possibly due to specific adaptations to one species making the bacteria less able to infect others," Harrison said.
In the new study, the researchers sought to better understand how MRSA travels between species. They analyzed the genetic makeup of MRSA strains from cats and dogs in England and discovered evidence of a "human source" for the germs in the animals.
The researchers also found evidence that the MRSA germs in the animals were developing resistance -- immunity -- to the antibiotic clindamycin, which veterinarians use in the U.K. The germs were less likely to have developed immunity against the antibiotic erythromycin, which is used less.