*2.5. PCR Detection of Antibiotic Resistance Genes*

Based on the phenotypic antibiotic resistance profiles, (29/30, 24/30, 22/30, 21/30, 17/30, 15/30) isolates showing resistance to β-lactam, rifampicin, methicillin, erythromycin, tetracycline, vancomycin respectively, were investigated for the presence of associated antibiotic-resistance genes (ARGs). These were *bla*Z, *rpo*B, *mec*A *erm*B, *erm*A, *erm*C, *tet*K, *tet*M, *van*A and *van*B genes respectively. The reactions were performed as singleplex PCRs in a total volume of 25 μL consisting of 12.5 μL 2X PCR master mix, 0.5 μL each of the forward and reverse primer, 6.5 μL nuclease-free water and 5 μL of template DNA performed in a T1000 Touch Thermal Cycler (Bio-Rad, Johannesburg, SA, USA). The amplicons were separated on 1.5% agarose stained with ethidium bromide, visualized and photographed using a transilluminator (UVITEC Alliance 4.7, Bio-Active., Ltd., Bangkok, Thailand). Table 1 shows the primer sequences used, and cycling conditions for PCR detection of *S. aureus* and antibiotic resistance gene markers.
