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Methicillin-resistant Staphylococcus aureus USA300 clone in long-term care facility
Pierre Tattevin1, Binh An Diep, Michael Jula
1Pontchaillou University Hospital, Rennes, France.
Emerging Infectious Diseases
|June 16, 2009
Summary
The USA300 clone of methicillin-resistant Staphylococcus aureus (MRSA) significantly increased in long-term care facilities between 2002 and 2006. This specific MRSA strain was predominantly found in skin infections.
Area of Science:
- Infectious Diseases
- Microbiology
- Epidemiology
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in healthcare settings.
- Understanding the clonal dynamics of MRSA is crucial for infection control.
- Long-term care facilities (LTCFs) are vulnerable settings for MRSA transmission.
Purpose of the Study:
- To analyze the longitudinal prevalence and characteristics of MRSA isolates in an LTCF.
- To investigate the increasing dominance of the USA300 clone within this setting.
Main Methods:
- Longitudinal analysis of 661 MRSA isolates collected from LTCF patients.
- Tracking the proportion of USA300 and non-USA300 MRSA clones over time (2002-2006).
- Comparing the distribution of MRSA clones based on infection site.
Main Results:
- The prevalence of the USA300 clone among MRSA isolates rose dramatically from 11.3% in 2002 to 64.0% in 2006 (p<0.0001).
- USA300 MRSA was significantly more likely to be recovered from skin or skin structure infections (64.3%) compared to non-USA300 MRSA (27.0%; p<0.0001).
Conclusions:
- The USA300 clone has rapidly become the dominant MRSA strain in this LTCF population.
- The association of USA300 with skin and skin structure infections highlights a potential transmission pathway in LTCFs.
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