Abstract

The objectives of this study were to examine methicillin-resistant Staphylococcus aureus(MRSA) strains recovered from major hospitals in King Saudi Arabia (KSA) to determine the percent of community acquired MRSA (CA-MRSA) phenotypically by conventional methods and genotypically by multiplex polymerase chain reaction (multiplex-PCR) for direct and simultaneous detection of S. aureus 16S rRNA, Panton–valentine leucocidin (PVL) and staphylococcal cassette chromosome mec (SCCmec) type IVa genes. Therefore, 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 phenotypically by conventional methods and genotypically by multiplex-PCR.  PCR enables rapid detection of all 135 bacterioloically identified S. aureus (100%) as well as the mecA gene in all strains phenotypically resistant to methicillin (100%). Moreover, it could detect the mecA gene in 8 strains (6%) phenotypically sensitive to methicillin. Only 18 strains (13.33%)   recovered from skin and soft tissue infections were positive for PVL and (SCCmec) type IV. The results of this study indicate that the incidence of patients with CA-MRSA disease had been increased in Riyadh, KSA.

Key words: Staphylococcus aureus, CA-MRSA, PVL gene, multiplex polymerase chain reaction.