Fig 2.

PCR detection of the insertion sequence (A) and dfrG (B). (A) The presence of the integration element was analyzed by PCR with primers specific for conserved regions flanking the integration site. S. pyogenes emm1-2 strains showed an ∼3.8-kb amplification product, indicating the integration element. As expected, S. pyogenes SF370 (negative control) showed no integration element, which is indicated by a 500-bp PCR product. (B) Specific PCR products of dfrG (500 bp) were detected in all tested emm1-2.2 strains, whereas SF370 was negative for these products.