Genetic analysis of mycobacterium tuberculosis strains isolated in Ural region, Russian Federation, by MIRU-VNTR genotyping.

SETTING

The Ural region in Russia is one of the areas most affected by a high incidence of tuberculosis (TB). Molecular epidemiological studies able to trace Mycobacterium tuberculosis transmission are of particular significance.

OBJECTIVE

To characterize the population of M. tuberculosis strains circulating in the Ural region, to detect the predominant genotypes and to evaluate their phylogenetic relationship and epidemiological significance.

DESIGN

Ninety-two M. tuberculosis clinical samples originating from the Ural region were genotyped using the MIRU-VNTR method.

RESULTS

Two major phylogenetically distinct groups of isolates were identified: the W-Beijing family (54.3%) and a previously unreported cluster, named the Ural group (15.2%). Forty-seven different MIRU profiles were identified, including 38 unique (41.3%) and 54 isolates grouped into nine clusters (from 2 to 28 isolates in each cluster). Genetic diversity within the clusters was shown by additional sub-typing of M. tuberculosis isolates in nine additional QUB-VNTR loci.

CONCLUSION

W-Beijing family isolates are associated with multiresistance to anti-tuberculosis drugs. It is possible that the strains of this family play a significant role in the spread of multidrug-resistant TB over the Ural region.