Abstract
The objectives of this study were to examine the strains of methicillin-resistant Staphylococcus aureus (MRSA) recovered from major hospitals in KSA by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) as an epidemiological marker. The strains were primarily examined by multiplex polymerase chain reaction (multiplex -PCR) for direct detection of S. aureus 16S rRNA, Panton-valentine leucocidin (PVL) and staphylococcal cassette chromosome mec (SCCmec) type IVa genes; 135 strains of S. aureus collected during the period of 2008 and 2009 from major hospital laboratories and public health centers, Riyadh, King Saudi Arabia were tested by conventional methods and (multiplex-PCR). Moreover, 24 strains were selected and examined by RAPD-PCR. PCR could detect all 135 bacterioloically identified as S. aureus (100%) and could detect the mecA gene in all strains phenotypicaly resistant to methicillin (100%), at the same time, it could detect the mecA gene in 8 strains (6%) phenotypicaly sensitive to methicillin. Only 18 strains (13.33%) recovered from skin and soft tissue infections were positive for PVL and (SCCmec) type IV. RAPD-PCR revealed 5 clusters on the basis of epidemiological data and phylogenetic tree.