Frequency of occurrence and types of mutations in the rpoB, katG, inhA, and ahpC genes associated with rifampicin and isoniasid resistance in M. tuberculosis strains circulating in the Kyrgyz Republic

Abstract

The availability of an MDR TB-Biochip for the express detection of Mycobacterium tuberculosis (MBT) strains resistant to rifampicin and isoniasid has been studied in 940 patients with pulmonary tuberculosis. The rpoB gene of rifampicin-resistant MBT strains circulating in the Kyrgyz Republic was shown to have substitutions at codons 531, 526, 516, 511, 513, 512, 533, and 522. MBT strains with mutations at codons 531 and 526 are prevalent. Among all rifampicin-resistant strains, MBT strains with the mutation of Ser531 → Leu occurred most frequently (59.7%). Isoniasid resistance is determined by mutations in the katG (94.5%), inhA (3.5%), and ahpC (1%) genes. Among isoniasid-resistant MBT strains, those with the mutation of Ser315 → Thr315 (94%) in the katG gene codon are predominant.