Emergence of methicillin-resistant Staphylococcus aureus with Panton-Valentine leukocidin genes in central Europe

Area of Science:

• Microbiology
• Infectious Diseases
• Genetics

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) strains producing Panton-Valentine leukocidin (PVL) are of increasing concern, especially those emerging in community settings.
• PVL is a toxin associated with severe staphylococcal infections, and its genetic determinant (lukS-lukF) is a key virulence factor.

Purpose of the Study:

• To investigate German MRSA strains for the presence of the lukS-lukF genes encoding PVL.
• To characterize MRSA strains positive for PVL genes regarding their molecular typing, resistance profiles, and SCCmec elements.

Main Methods:

• Polymerase chain reaction (PCR) was used to detect the lukS-lukF determinant in MRSA strains.
• Molecular typing included SmaI macrorestriction, spa sequencing, and multilocus sequence typing (MLST).
• Resistance genes and SCCmec elements were also characterized by PCR.

Main Results:

• Since late 2002, 28 MRSA infections in Germany were linked to PVL-producing strains (9 community-acquired, 19 nosocomial).
• Twenty-seven of these isolates shared a common genomic profile: MLST type 80, spa type 44, and a SmaI pattern consistent with French/Swiss community-acquired MRSA.
• These strains were resistant to oxacillin, ciprofloxacin, tetracycline (tetM), and fusidic acid (encoded by plasmid-located far-1 gene).

Conclusions:

• PVL-producing MRSA strains, particularly MLST type 80, have emerged in Germany, causing both community and hospital-acquired infections.
• These strains possess a distinct genetic background and a multi-drug resistance pattern, highlighting the need for surveillance.
• One isolate represented a US-origin community MRSA (cMRSA) with MLST type 1.