Detection of MecA gene in clinical isolates of Staphylococcus aureus by multiplex-PCR, and antimicrobial susceptibility of MRSA

Multiplex-PCR protocols were designed in order to make a rapid identification of MRSA. MecA, femB, and 16S rRNA genes were amplified for making a detection of MRSA. The incidence of MRSA in the clinical isolates of Staphylococcus aureus was examined by using a multiplex-PCR assay. The mecA gene was detected in 266 strains out of 336 clinical isolates of S. aureus, thus the incidence of MRSA was approximately 76.5%. The MRSAs of 247 strains (96.1%) showed resistance to more than eight species of the antimicrobial agents tested. The isolates of MRSA showed 27 different antimicrobial-resistant patterns. The results indicate that many different MRSA strains having high multidrug resistance are actually prevalent in Korea. Also, VISA was screened from the MRSA. Two strains were grown on the BHI agar plate supplemented with 8 mug/ml of vancomycin at a frequency of 1/10(8) colony forming units or higher.