The level of katG and inhA gene mutations of drug-resistant strains of Mycobacteria tuberculosis spreading in Azerbaijan

The continuing spread of drug-resistant tuberculosis (TB) is one of the most urgent and difficult challenges facing global TB control. <bold>Aim:</bold> Study of molecular-genetic characteristics of M. tuberculosis strains obtained from MDR and XDR TB patients in different regions of Azerbaijan in 2012-2021. Materials and methods: Biological material (sputum mostly) obtained from 3779 initial and 2101 repeated patients who entered the Reference laboratory in Azerbaijan was studied. At the initial stage, the material was examined using Genexpert MTB/Rif, and then it was cultured in liquid medium Middlebrook 7H9 in Bactec MGIT960 analyzer. M. tuberculosis strains were isolated from the resulting cultures and examined by Gene Type MTBDR plus ver.2.0 polymerase chain reaction. <bold>Results:</bold> The level of mutation in the katG gene, which controls resistance to isoniazid(Iso), among new and relapsed Iso-resistant patients in Azerbaijan made up 79.99% and 75.77% respectively. The inhA gene mutations in Iso-resistant patients is 8.02% in new patients and 7.09% among relapsed patients. The existence of katG and inhA mutations at the same time in the same patients was observed in 12.36% of new and 17.99% of relapsed TB patients with Iso resistance. <bold>Conclusions:</bold> It seems that mutations in different genes and their level are related to different strains spread in Azerbaijan. The level of the katG mutations that lead to Iso resistance is higher in new and relapsed TB patients, and there is no significant difference between them. The existence of katG and inhA mutations simultaneously in relapsed TB patients with Iso resistance is higher than in new cases, p<0.05.