Disinfecting for Methicillin-Resistant Staphylococcus pseudintermedius in the Clinic

William Oldenhoff, DVM, DACVD, Animal Dermatology Center, Studio City, California

ArticleLast Updated January 20212 min read

In the literature

Soohoo J, Daniels JB, Brault SA, Rosychuk RAW, Schissler JR. Efficacy of three disinfectant formulations and a hydrogen peroxide/silver fogging system on surfaces experimentally inoculated with methicillin-resistant Staphylococcus pseudintermedius. Vet Dermatol. 2020;31(5):350-e91.


The Research …

Thorough environmental disinfection is critical in veterinary clinics to limit nosocomial infections. Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is of particular importance for veterinary patients, as it is one of the most commonly isolated resistant pathogens in dogs and cats,1 and hospitalization and frequent visits to the clinic have been identified as risk factors for infection.2,3 There are currently no commercial disinfectant sprays or foggers effective against MRSP.

This study investigated the activity of 4 products on MRSP: a hydrogen peroxide and silver fogging system, a quaternary ammonium product, an accelerated hydrogen peroxide product, and a hydrogen peroxide and silver product. Surfaces were inoculated with MRSP then cleaned per manufacturer recommendations with the tested products.

To test the fogging system, 8 inoculated samples were placed in various locations in a clinic examination room. The fog was deployed and the room sealed for the recommended duration. Researchers found that the quaternary ammonium and accelerated hydrogen peroxide products provided mean reduction in MRSP cfu counts of 99.97% and 99.98%, respectively. A mean reduction of 97.81% was noted with the hydrogen peroxide and silver product and 52.14% with the fogging system.


… The Takeaways

Key pearls to put into practice:

  • The sprays used in this study demonstrated superior activity as compared with the fogging system. However, using a disinfectant after every patient (versus which product is used) is the most important component of cleaning. The quaternary ammonium and accelerated hydrogen peroxide products demonstrated superior efficacy in MRSP disinfection. The hydrogen peroxide and silver product also provided significant reduction and may be acceptable in a clinical setting. Ultimately, cleaning is the most critical part of preventing nosocomial infections.

  • The hydrogen peroxide and silver fogging system cannot be recommended as a sole means of disinfection but may have a role as an adjunct to disinfection, particularly in areas in the clinic where the risk for infection is higher (eg, surgery suite).

  • The environment is just one source of nosocomial infections. Other sources include hands and shared grooming equipment, and thorough and frequent cleaning is critical to preventing the spread of microbes.