CLINICAL AND EPIDEMIOLOGICAL VALUE OF VARIOUS GENOTYPES OF M. TUBERCULOSIS AND CHANGES IN THEIR TRANSMISSION IN SARATOV REGION DURING 4-YEAR PERIOD

Abstract

Goal: to detect specific features of circulation of tuberculosis mycobacteria belonging to various genotypes in Saratov Region, define their clinical and epidemiological value and changes in the transmission during 4 years of monitoring (2014-2017).Materials. 310 clinical isolates of M. tuberculosis were studied, all isolates were obtained from sputum of new pulmonary tuberculosis patients. The toolkit of Spoligo-Biochip (OOO BIOCHIP-IMB, Moscow) was used for spoligotyping and hybridization on the biological microchips.Results. It was found out that in 2014-2017 in Saratov Region,11 genotypes of M. tuberculosis were circulating (Bejing, Beijing-like, Haarlem+Ural, LAM, T, Microti, Rus 1, EAI, Canetti, Cas, Manu), of them, Bejing, Beijing-like, Haarlem и T. dominated. The homogeneous genetic structure was typical of Beijing и Beijing-like with large clusters of spoligotypes of (SIT) 1, 265 и 250. Beijing SIT 1 was confidently more frequent in those with severe forms of tuberculosis and bacillary excretion. M. tuberculosis of Haarlem and T genotypes had a higher heterogeneity and lower clusterization. Beijing and Haarlem were the most unfavorable from the epidemic point of view and they were confidently more frequent in patients with lung tissue destruction and bacillary excretion. For 2016-2017, the positive change in tuberculosis epidemics was registered in Saratov Region, namely, the circulation of Beijing decreased while the circulation of T genotype increased.

Keywords

• микобактерии туберкулеза
• генотипы
• сполиготипирование