Mutations of the gyrA gene of mycobacterium tuberculosis leading to XDR tuberculosis in Kyrgyz Republic

In the treatment of multidrug-resistant tuberculosis (MDR) the second line drugs are prescribed and among them the most ones are fluroquinolones. But the emergency problem of the recent years is the development of fluroquinolone resistance or XDR tuberculosis. The XDR is associated with mutations in the gyrA gene which controles the proliferation of M.tb. Aim: Analysis of mutations of the gyrA gene of M. tuberculosis (M.Tb) strains from patients of penitentiary system and civilian hospitals of Kyrgyz Republic. Materials and methods: Sputum samples of 79 pulmonary tuberculosis (TB) patients were analyzed by biochip assay to detect the gyrA mutations of M.tb. From all samples the 33 sputum samples were taken from patients in the penitentiary system and 46 sputum samples were taken from patients in the civilian sector. Results: M.tb resistant to fluroquinolone were found in 8.7% of TB patients from the civilian sector and in 6% of TB patients from the penitentiary system which gives the resistance to fluroquinolones of about 7.6% in general TB patients subpopulation. The detailed analysis of the mutations of gyrA gene revealed its location mainly in codons 90 and 94. The most frequent mutations was Asp94Gly (66.6%) than it was Ala90Val (16.6%). One case had the combination of both mutations Asp94Gly and Ala90Val. Conclusion: In XDR tuberculosis patients from Kyrgyz Republic the resistance of M.tb to fluroquinolones is mainly caused by Asp94Gly and Ala90Val mutations of gyrA gene.