Abstract:
The Beijing genotype is the most distributed M. tuberculosis family in Kazakhstan. In this
study, we identified dominant Beijing clusters in Kazakhstan and assessed their drug susceptibility
profiles and association with the most widely spread mutation Ser531Leu of the rpoB gene and
the mutation Ser315Thr of the katG gene associated with resistance to rifampicin and isoniazid,
respectively. M. tuberculosis isolates (n = 540) from new TB cases were included in the study. MIRUVNTR genotyping was performed for 540 clinical isolates to determine M. tuberculosis families
using 24 loci. RD analysis was additionally performed for the Beijing isolates. The identification
of mutations in the drug-resistance genes of M. tuberculosis was performed with allele-specific realtime PCR and Sanger sequencing. The Beijing genotype was identified in 60% (324/540) of the
clinical isolates. Central Asian/Russian cluster 94-32 was the most distributed cluster among the
Beijing isolates (50.3%; 163/324). Three other dominant Beijing clusters were identified as 94-33
(3.4%; 11/324), 100-32 (3.1%; 10/324) and 99-32 (3.1%; 10/324). The Beijing genotype was associated
with drug-resistant TB (p < 0.0001), including multidrug-resistant TB (p < 0.0001), in our study.
An association of the mutation Ser531Leu of the rpoB gene with the Beijing genotype was found
(p < 0.0001; OR = 16.0000; 95%CI: 4.9161–52.0740). Among the Beijing isolates, cluster 94-32 showed
an association with MDR-TB (p = 0.021). This is why the evaluation of the Beijing genotype and its
clusters is needed to control MDR-TB in Kazakhstan.
