MRSA (Methicillin-resistant Staphylococcus aureus) Infection
|Animal group affected
||Prevention and Control
|Direct contact with contaminated surfaces,
contact with contaminated surfaces
|Minor to severe: skin redness, pustule red lesions, boils, rash fever, headache, malaise
||Typically mild, but may be fatal in the immune compromised. There are no reports of mortality rates in animals, but this is becoming more common in foals in ICU.
||Wound care, and susceptible antibiotics as determined by testing, if needed
||Personal/ environmenthygiene. Wear gloves when working with known infected animal/
|Fact Sheet compiled by: Tara M. Harrison
|Sheet completed on:
|Fact Sheet Reviewed by:
Julie Napier, Kathryn Gamble, Dalen Agnew, Christine Fiorello, and Donald Janssen
|Susceptible animal groups
Mammals, avian (+/-)
Methicillin-resistant Staphylococcus aureus, also Methicillin-resistant Staphylococcus pseudointeritidis
Crowded living conditions, group work and gyms, closely shared work and locker spaces, long-term care or rehabilitation facilities, hospitals.
7% of people in hospitals and 2% of people in the community can have MRSA colonization with no clinical signs. It is thought that <10% to up to 90% of dogs and cats can be non-clinical carriers as well.
Healthy people and animals typically do not develop disease under normal circumstances.
Skin redness, “pimple-like” red lesions, boils, rash, fever, headache, malaise
Primarily skin infections or skin wounds although necrotizing pneumonia or other general infection may occur.
|Post mortem, gross, or histologic findings
This bacterium can produce a wide spectrum of clinical disease, particularly of the skin. In humans these diseases including impetigo, folliculitis, furunculosis, cellulitis, abscesses and wound infections. Other diseases include necrotizing pneumonia, endocarditis, septic arthritis, osteomyelitis, meningitis, and septicemia. In animals abscesses, dermatitis, fistulas have been reported; as well as pneumonia, rhinitis, bacteremia, septic arthritis, osteomyelitis, omphalophlebitis, metritis, and mastitis. Post-mortem lesions are similar to any other purulent bacterial infection and vary with the organ or tissue involved in the infection.
Bacterial culture and antibiotic susceptibility testing
|Material required for laboratory analysis
Culture swab or tissue sample of the affected area
|Relevant diagnostic laboratories
Any laboratory capable of bacteriologic culturing is capable of diagnosing MRSA
Typically resistant to all ß-lactam agents, including cephalosporins and carbapenems. Hospital-associated MRSA isolates often are resistant to multiple commonly used antimicrobial agents, including erythromycin, clindamycin, and tetracycline, while community-associated MRSA isolates are often resistant only to ß-lactam agents and erythromycin.
Treatment specifically depends on the specific MRSA isolate, and its antibiotic sensitivity profile. This will require sensitivity testing on ALL isolates (and possibly repeated testing on isolates from a single case).
In humans: Vancomycin and two newer antimicrobial agents, linezolid, and daptomycin are used for severe Hospital-associated MRSA infections
|Prevention and control
Follow all wound care procedures recommended by veterinarian or physician. Practice good hygiene; wash hands often. Keep cuts and scrapes clean and cover with bandages, avoid direct contact with cuts and scrapes, use gloves to treat wounds, replace and disinfect items in holding or exhibit frequently. Porous surfaces such as blankets need to be washed in hot water using bleach and a hot air dryer to help kill bacteria. Alcohol-based hand cleaners are effective when hands aren’t dirty.
Isolate the patient if possible to minimize staff contact and exposure. Animal cages should be clearly marked with the diagnosis and preventative measures required. Maintain infected animal in isolation or away from other animals until wound(s) are healed or cultures are negative. If treatment of the animal is not possible, humane euthanasia of infected animal may be warranted to minimize risk of infection to staff and other animals.
|Suggested disinfectant for housing facilities
After cleaning gross contamination, 1 tablespoon of bleach to one quart of water, fresh daily, leave solution on to dry, or wipe dry after 10 minutes. Other disinfectants effective against Staphylococcus aureus or Staph are also most likely also effective against MRSA. Check the disinfectant product’s label on the back of the container to verify it is effective against it.
Public health officials may need to be notified if zoonotic transmission occurs, depending on the state.
|Measures required under the Animal Disease Surveillance Plan
|Measures required for introducing animals to infected animal
Maintain infected animal in a quarantine situation until the wound is healed. Do not introduce infected animal to an animal with a compromised immune system.
|Conditions for restoring disease-free status after an outbreak
Clean infected environment with diluted bleach to the extent possible. Minimize contact of infected staff with animal.
|Experts who may be consulted:
J. Scott Weese DVM DVSc DipACVIM
Dept of Pathobiology
Ontario Veterinary College
University of Guelph
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