Figure 1.

Scanned image of gel showing results of amplified DNA fragments of positive control (lanes 1–3) and 18 test isolates (lanes 4–21). PCR amplicons of mef(A) (298 bp) gene were shown in lanes 6, 13, 14 and 19, erm(B) (224 bp) gene in lanes 18 and 21 and a combination of mef(A) and erm(B) gene was shown in lane 8 and 10. A lane with no band indicates the absence of both genes

Notes: Lane L = 100 bp DNA ladder; Lane N = negative control (DNase-free water); Lane 1 = positive control (S. pneumoniae ATCC 700673 (Hungary^19A-6) - for erm(B) gene; Lane 2 = positive control (S. pneumoniae ATCC 51916) (Tennessee23F-4) - for mef(A) gene; Lane 3 = positive control (S. pneumoniae ATCC 700673 (Humgary^19A-6) + S. pneumoniae ATCC 51916 (Tennessee^23F-4) - for erm(B) gene + mef(A) gene combination; Lane 4–21 = S. pneumoniae isolates