[Molecular epidemiology of rifampicin mono-resistant Mycobacterium tuberculosis].

Purpose: We aimed to investigate the prevalence and possible transmission routes of rifampicin (RFP) mono-resistant Mycobacterium tuberculosis strains.

Methods: Drug susceptibility testing was used to identify 15 RFP-resistant strains out of 4633 M. tuberculosis isolates. Sequencing of the rpoB gene and VNTR analysis were performed to further confirm the genetic classification.

Results: Resistance-conferring mutations in the RFP resistance-determining region (RRDR) of the rpoB gene were found in 14 of the 15 strains with phenotypic RFP mono-resistance. VNTR analysis revealed 2 clusters of 5 identical strains each.

Conclusions: Although the community prevalence of RFP mono-resistant M. tuberculosis is low, the results of VNTR analysis suggested that rather than being recently transmitted, these strains may have been widely transmitted as latent infections in the population.