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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
PubMed

Insights

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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