Study objectives: To detect the genes encoding an important virulence factor, Panton-Valentine leukocidin, in S. aureus isolates from clinical specimens. Material and Methods: S. aureus strains from clinical specimens, mainly from patients with skin diseases, referred by microbiological laboratories of the Czech Republic. The strains were identified by both conventional phenotyping methods and molecular biological procedures, in particular polymerase chain reaction. Results: Altogether 108 (8.1 %) of 1336 S. aureus strains had the genes encoding Panton-Valentine leukocidin in DNA. Only 11 of these strains were MRSA. Conclusions: S. aureus strains producing Panton-Valentine leukocidin play an important role in serious infections, particularly of the skin. NRL for Staphylococci, National Institute of Public Health, Centre of Epidemiology and Microbiology, is able to detect the production of this toxin, under optimal conditions, within two days.

        Key words: Staphylococcus aureus – Panton-Valentine leukocidin – CA-MRSA.