People and their pets as well as other companion animals like horses share the same compliment of methicillin-resistant Staphylococcus aureus (MRSA) bacteria. Mark Holmes, senior lecturer in preventive veterinary medicine at the University of Cambridge in England, and colleagues have proven this transfer to be possible for the first time. The research was reported in the May 13, 2014, edition of the journal mBio®.
The researchers sequenced the genomes of 46 strains of methicillin-resistant Staphylococcus aureus from cats and dogs. The samples were collected over four years. Samples of fluids from the animal’s urine, cerebrospinal fluid, nasal discharge, blood, and heart showed the same compliment of MRSA as their human owners.
The development of MRSA in human’s companion animals was found to parallel the development the same strains of MRSA in humans. Human MRSA infections were first found in 1990. A comparison of the MRSA compliment of humans and their pets showed a high level of genetic similarity in the strains of MRSA that infect both animals and people. Transfer of MRSA in animals was also found to occur in veterinary hospitals and kennels. Proximity to an infected human or animal increases the probability that a companion animal will become infected with a strain of MRSA.
The researchers found very little genetic difference between the strains of MRSA that infect companion animals and their owners. This finding indicates little if any evolutionary adaptation of MRSA has occurred in cats and dogs. The development of MRSA is thought to have occurred in humans first due to the overuse of antibiotics and the use of antibiotics in feed for animals that people eat. Similar overuse of antibiotics to treat animals for infections may have added to the development of MRSA in pets.
The researchers claim that the risk of infection, damage, or death to pets from human MRSA is minimal at present. One advantage that dogs in particular have is their saliva is antiseptic naturally and licking wounds is a dog’s health insurance. The researchers do advise maintaining a regular hygiene routine for your pet to avoid MRSA infection from you or other animals.