FIG. 1.

Chromosome locus of the GS5 strain containing the gtfB and gtfC genes (GenBank accession number M17361). (A) Primer pairs used for specific amplification of gtfB and gtfC genes are represented as black and shaded arrows, respectively. The restriction sites of the 5.2-kb gtfB and 4.3-kb gtfC amplicons are represented by the dashed lines; within them, the size of fragments are indicated. (B) PCR products obtained with the GTFBF-GTFBR (lane 1) and GTFCF-GTFCR (lane 2) primer pairs. In 18 isolates, efficient amplification of the gtfC genes was not obtained. Instead, PCRs yielded two weaker products as shown in lane 2b. Thus, RFLP analysis of gtfC could not be performed with these 18 strains. ORF, open reading frame.