PVL-positive MRSA in Austria.

Area of Science:

• Microbiology
• Infectious Diseases
• Epidemiology

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant public health threat globally.
• Panton-Valentine leukocidin (PVL) is a toxin produced by some S. aureus strains, often associated with severe infections.
• Understanding the prevalence and characteristics of PVL-positive MRSA is crucial for effective control strategies.

Purpose of the Study:

• To provide the first comprehensive overview of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) strains circulating in Austria.
• To compare the epidemiological situation of PVL-positive MRSA in Austria with international data.
• To identify common sequence types and prevalence rates of PVL-positive MRSA.

Main Methods:

• Analysis of 1150 MRSA isolates (from infections and colonisation) collected between 2001 and 2006 in Austria.
• Detection of Panton-Valentine leukocidin (PVL) genes in MRSA isolates.
• Multilocus sequence typing (MLST) to determine the genetic relatedness of PVL-positive MRSA strains.

Main Results:

• Ninety-four PVL-positive MRSA strains were identified, representing a notable prevalence.
• The most common sequence types (STs) among PVL-positive MRSA were ST8, ST152, ST30, ST80, and ST5, with ST22 and ST777 also detected.
• PVL-positive MRSA isolates showed a higher prevalence in younger patients compared to nosocomial MRSA, which predominantly affected the elderly.
• Two PVL-positive MRSA strains identified in Austria were not yet widespread in Western Europe, indicating unique local clonal spread.

Conclusions:

• A relatively high prevalence of PVL-positive MRSA strains was observed in Austria during the study period.
• Several MRSA clones carrying PVL genes are actively spreading within Austria.
• The findings highlight the emergence of specific PVL-positive MRSA clones in Austria, necessitating ongoing surveillance and targeted interventions.