Is International Travel an Emerging Issue on Transmission of Beijing Lineage Mycobacterium tuberculosis?

Figure 3

Agarose gel profiles displaying the PCR products of Beijing multiplex PCR and conventional PCR. (a) Agarose gel profile displaying the PCR products of Beijing multiplex PCR (M; 50 bp DNA marker; lanes 1, Beijing lineage positive control (a confirmed Beijing strain); 2–6, amplicons from culture isolates; 7, negative control (water); 8, non-Beijing control (the standard Mycobacterium tuberculosis strain H37Rv)). (b) Agarose gel profile displaying the PCR products of Beijing multiplex PCR and conventional PCR for the two culture-positive isolates in which the Beijing/non-Beijing status could not be ascertained (M; 50 bp DNA ladder; lanes 1, Beijing multiplex PCR product of culture isolate (a); 2, Beijing multiplex PCR product of culture isolate (b); 3 and 4, positive controls (the standard Mycobacterium tuberculosis strain H37Rv); 5, conventional PCR product of culture isolate (a); 6, conventional PCR product of culture isolate (b); 7, negative control (water)).