V originále
Phenotypic and genotypic characteristics of 59 PVL positive strains isolated from clinical specimens in the Czech Republic are described. Methods: The RPLA method was used for detection of superantigens. To confirm toxigenicity PCR screening for the sea-sej, tst, eta and etb genes was carried out. Resistance to 12 antibiotics was tested by the disk diffusion method. Phage typing was performed by the standard method using the Int. Set of Phages. Carriage of the lukS-PV and lukF-PV genes for PVL and mecA gene was tested by a multiplex PCR method. The MRSA PVL+ strains were characterized by SmaI macrorestriction analysis resolved by PFGE, spa typing, SCCmec typing by multiplex PCR, prophage typing and preliminary matching of prophage types with PVL production. Results: The presence of the lukS-PV and lukF-PV genes was detected in 59 (6.6%) of 889 S. aureus strains isolated mainly from lesions, wound infection, skin and soft tissue abscesses. Production of enterotoxins A-D was found in 12 (20%) of the 59 PVL+ strains, two strains also produced TSST-1 and one strain was a producer of exfoliative toxin A. Only six strains were MRSA and were classified into SCCmec type IV, ordinarily found in community acquired MRSA strains. Genotypic properties of PVL+ MRSA strains were correlated with the known European MRSA types. Conclusions: The Czech Ref. Laboratory for Staphylococci has been paying attention to PVL+ S. aureus strains since 2004. By March 31, 2006, we found 59 (7.8%) of 889 isolates, mainly from lesions, to carry genes for PVL. Most (78%) PVL+ strains were phage typeable and were predominantly classified into phage group II (53%). Six MRSA PVL+ isolates carrying SCCmec type IV yielded five distinct and unrelated SmaI PFGE patterns and were of unrelated spa types 003, 008, 186, 311 and also 044 lukS-lukF positive CA-MRSA, widely disseminated in Europe.