Tracking the epidemiology of methicillin-resistant Staphylococcus aureus strains producing Panton-Valentine leukocidin in Greece

Abstract number: 1733_1094

Chini V., Foka A., Petinaki E., Meugnier H., Kolonitsiou F., Garantziotou D., Bes M., Etienne J., Spiliopoulou I.

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is recently associated with an increasing number of community-acquired infections (CA-MRSA), including superficial, deep-seated infections and pneumonia. CA-MRSA harbours the Staphylococcal Cassette Chromosome IV or V (SCCmec) and the genes encoding the Panton-Valentine leukocidin (PVL). We have investigated the distribution and clonal evolution of CA-MRSA during 2005–2006 in Greece.

Methods:S. aureus isolates from three hospitals in Western and Central Greece were identified by conventional tests, followed by the determination of MIC of oxacillin by the agar dilution method. PBP2a production was investigated by a Latex agglutination test (bioMérieux). SCCmec types, agr groups and the presence of lukS and lukF genes (encoding PVL) were defined by PCRs. Clonal types were determined by MLST. CA-MRSA were isolated from patients without any predisposing risk factors and identified on the basis of their genotypes.

Results: A total of 1,541 S. aureus isolates were collected from different patients from January 2005 until June 2006. Among them 697 isolates (45%) were MRSA (495 from the Department of Outpatients, OUTP) and 490 (70%) PVL-positive (443 from the OUTP). An increasing rate of the total S. aureus infections was observed with a parallel increase of PVL-positive CA-MRSA. The great majority of CA-MRSA was associated with skin and soft tissue infections, but five cases of acute osteomyelitis and one pneumonia were diagnosed. The majority of CA-MRSA (432) belonged to the major European clone, which is ST80, agr 3, SCCmec IV, while the rest 11 belonged to a new emerging clone, spread also in Europe, ST377, agr 1 and SCCmec type V. Most of the PVL-positive MRSA were associated with community-acquired infections, but 47 PVL-positive MRSA of ST80 were isolated from hospital-acquired infections, mainly at the departments of Orthopaedics and Surgery.

Conclusions: There is an unusual epidemiology of PVL-positive CA-MRSA in Greece where, we are encountering an increasing rate of S. aureus infections, due to CA-MRSA producing PVL and causing mainly superficial but also deep-seated infections. The European CA-MRSA clone seems to be spread rapidly, but a new clone is also showing up.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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