Methicillin-resistant Staphylococcus aureus in England and Wales

Area of Science:

• Medical Microbiology
• Infectious Diseases Epidemiology

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) emerged shortly after methicillin introduction in 1960.
• Antibiotic usage patterns influenced MRSA isolation rates, with a notable rise in the early 1980s.

Purpose of the Study:

• To review surveys on MRSA frequency, distribution, and strain variations.
• To analyze the emergence and spread of epidemic MRSA (EMRSA) strains.

Main Methods:

• Review of historical survey data on MRSA isolation.
• Characterization of MRSA strains using phage typing, antibiogram, and molecular typing.
• Tracking the geographical distribution and temporal trends of specific EMRSA strains.

Main Results:

• The first epidemic strain, EMRSA-1, emerged in 1981 and spread widely before declining.
• EMRSA-2 remained localized, while EMRSA-3 spread across eight health regions by 1991.
• At least 11 other epidemic and 10 endemic MRSA strains were identified.
• Imported MRSA strains demonstrated epidemic potential and led to local spread.

Conclusions:

• Continued surveillance of epidemic MRSA strains is crucial.
• Identifying simple markers for prompt detection and control is necessary.
• Understanding strain diversity and spread is vital for effective MRSA management.