Mycobacterium tuberculosis RD-Rio Strain in Kazakhstan

Increasing circulation of multi-drug resistant tuberculosis strains in Buryatia, high-burden and ethnically diverse region in the Russian Far East

Buryatia is a multidrug-resistant tuberculosis (MDR-TB) high-burden region in the Russian Far East with ethnically diverse population (30 % Mongoloid Buryats and 65 % Russians). Two hundred M. tuberculosis strains from newly-diagnosed patients were subjected to phenotypic testing and genotyping. The Beijing genotype was more prevalent among Russians than Buryats (68 % vs 53 %; P = 0.055). European non-Beijing genotypes (LAM, Ural, Haarlem) were double more prevalent in Buryats vs Russians (39.2 % vs 20.5 %; P = 0.01). Higher prevalence of Beijing among former prison inmates (79 % vs 61 % in other patients, P = 0.1) suggests its increased transmissibility. The Russian epidemic cluster B0/W148 was in 9.5 %, double smaller than elsewhere in Siberia. The hypervirulent Beijing 14717-15-cluster was endemic in Buryatia but paradoxically enough, it was more frequently isolated from Russians than Buryats (9.1 % vs 3.9 %; P = 0.2). Beijing subtypes B0/W148, CAO, and 14717-15 were associated with poly/multi-drug resistance (P = 0.01-0.0001). HIV coinfection was more frequent in Russians than in Buryats: 35/141 (24.8 %) vs 5/51 (9.8 %), P = 0.03. To conclude, M. tuberculosis population structure in Buryatia retained its singularities compared to other parts of Russia and remains strikingly different from the neighboring Mongolia. A circulation of strongly MDR-associated Beijing subtypes and drug-resistant non-Beijing strains highlights a risk of their broader dissemination.

Genomic analysis of Latin American-Mediterranean family of Mycobacterium tuberculosis clinical strains from Kazakhstan

The human-adapted strains of the Mycobacterium tuberculosis complex (MTBC) comprise seven phylogenetic lineages originally associated with their geographical distribution. Here, we report the genomes of three drug-resistant clinical isolates of the Latin American-Mediterranean (LAM) family collected in Kazakhstan. We utilised whole-genome sequencing to study the distribution and drug resistance of these isolates. Phylogenetic analysis grouped the genomes described in this study with the sequences from Russia, Uzbekistan, and Kazakhstan belonging to the LAM family. One isolate has acquired extensive drug resistance to seven antituberculosis drugs. Our results suggest at least two multi-drug resistant (MDR)/extensively drug-resistant (XDR)-associated genotypes of the LAM family circulate in Kazakhstan.

Spatiotemporal dynamics of drug-resistant Mycobacterium tuberculosis: Contrasting trends and implications for tuberculosis control in EU high-priority country

Different and contrasting trends related to human migration and the implementation of health control programmes influence the spread of drug-resistant tuberculosis (TB). We analysed the Mycobacterium tuberculosis population structure in Estonia, a high-priority EU country for TB control, to detect the dynamic changes and underlying factors. The study collection included 278 M. tuberculosis isolates recovered in 1999 and 2014-2015. The isolates were subjected to drug susceptibility testing, genotyping and analysis of sublineage/cluster-specific markers and drug resistance mutations. The Beijing genotype was the most prevalent, and its rate increased from 28.6% in 1999 to 38.5% in 2015 (p = .09). The non-Beijing strains represented Euro-American lineage (Latin American Mediterranean [LAM], Ural, Haarlem, T, X genotypes) and Indo-Oceanic lineage (one EAI-IND isolate). The proportion of isolates resistant to two or more drugs increased from 22.4% to 29.1% (p = .1). The pre-XDR/XDR isolates were identified only within the Beijing genotype. In contrast, the drug resistance rate decreased in the LAM genotype from 42.1% to 11.8% (p = .05). The Beijing B0/W148-cluster ('successful Russian strain') included only MDR, pre-XDR or XDR isolates. All B0/W148-cluster isolates were resistant to two or more drugs compared to 28% of the Beijing 94-32-cluster (p = .0002). The Beijing genotype was not identified in the isolates from patients born in Estonia before 1940 compared to its 35.2% rate among other patients. In summary, the circulation of the highly drug-resistant isolates of the Beijing B0/W148 subtype, the increased prevalence of the Beijing genotype among HIV-coinfected patients and the increased number of patients with alcohol abuse (47.5%) present major challenges of the current TB control in Estonia. The Beijing genotype was likely brought to Estonia after 1945 due to the massive human influx from the Soviet Union. In contrast, the main genotypes of the Euro-American lineage were likely endemic in Estonia during all 20th century.