Positive epistasis of major low-cost drug resistance mutations rpoB531-TTG and katG315-ACC depends on the phylogenetic background of Mycobacterium tuberculosis strains.
Subgroup analyses based on ethnicity revealed that the GCC haplotype was associated with a higher risk of TB in Europeans, whereas the ACC haplotype was associated with a lower TB risk in both Asians and Europeans.
Significant difference was observed in IL10 GCC and ACC haplotypes distribution between TB and control subjects (Pc: 0.000, O.R 2.22, 95% CI 1.45-3.41; Pc: 0.004, O.R 0.53, 95% CI 0.35-0.81).
The data also showed that mutations other than AGC to ACC at codon 315 in the katG gene occur frequently in M. tuberculosis isolates recovered from Middle Eastern patients and should be incorporated in a rapid screen for the detection of mutations for isoniazid-resistance in the katG gene from this ethnic group.