MRSA Contamination of Home and Pets May Contribute To Reinfection and Resistance Interview with:


Mr. Shahbazian

Mr. Jonathan Shahbazian, MPH
Johns Hopkins Bloomberg School of Public Health
Baltimore What is the background for this study? What are the main findings?

Response: Our study was designed to investigate risk factors for drug resistance in MRSA found in dust on surfaces in the home. We undertook this investigation because we were concerned first that people living in the home could pick up MRSA from these surfaces, and second, that if they picked up drug-resistant MRSA, it would be more difficult to treat them.

Our main finding was that use of antibiotics by either people or pets in the home, as well as use of biocidal cleaning products, was associated with multidrug resistance (MDR) in home MRSA. This study is the first to report that use clindamycin in either humans or domestic animals was not associated with risk of MDR in the home environment.

We also found that mupirocin treatment was associated with a slight increase in mupirocin resistance in the household environment, which could complicate decolonization efforts that rely on use of nasal mupirocin ointment. We found that 100% of our MRSA isolates from rural homes were MDR, suggesting living in a rural household may be a risk factor. We also found the presence of domestic pets was associated with MDR MRSA in the home environment while the presence of unwanted pests, such as mice or cockroaches, was associated with non-MDR MRSA strains at the three-month visit. What should clinicians and patients take away from your report?

Response: MRSA is a common bacterial agent implicated in skin and soft tissue infections (SSTIs) in both community and healthcare settings. Patients with CO-MRSA infections shed MRSA into the environment and may be re-exposed to MRSA strains from that reservoir. People interact with natural and built environments, therefore understanding the relationships between humans and animals as well as characteristics of environmental reservoirs is important to advance strategies to combat antimicrobial resistance. How we interact with the environment may influence the frequency and duration of exposure, which in turn may impact the duration of MRSA colonization or probability for recurrent colonization and infection.

Therefore, MRSA contamination of the home environment may contribute to human and animal recolonization and decolonization treatment failure. What recommendations do you have for future research as a result of this study?

Response:   Future research should replicate these results in a larger study in order to confirm our results. We would also like to encourage taking the environment and animals into account when studying multidrug resistance in MRSA. It was fascinating to learn about the importance of considering environmental risk factors to evaluate MRSA infections in the household and our study will hopefully help influence future research and decolonization treatments. Is there anything else you would like to add?

Response: Our research group is deeply involved in One Health research, with equal emphasis on the environmental, animal, and human aspects of this work. The work in this study helped contribute conceptually to the development of the Checklist for One Health Epidemiological Reporting of Evidence (COHERE), which is a newly-published guide to help the conduct and reporting of One Health studies ( Thank you for your contribution to the community.


J. H. Shahbazian, P. D. Hahn, S Ludwig, J Ferguson, P Baron, A Christ, K Spicer, P Tolomeo, A. M. Torrie, W. B. Bilker, V. C. Cluzet, B Hu, K Julian, I Nachamkin, S. C. Rankin, D. O. Morris, E Lautenbach, M. F. Davis. Multidrug and mupirocin resistance in environmental methicillin-resistant Staphylococcus aureus (MRSA) collected from the homes of people diagnosed with a community-onset (CO-) MRSA infection. Applied and Environmental Microbiology, 2017; AEM.01369-17 DOI: 10.1128/AEM.01369-17


Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.


[wysija_form id=”1″]






Last Updated on October 4, 2017 by Marie Benz MD FAAD