Pulmonary tuberculosis epidemiology and genetics in Kazakhstan.

Background: Tuberculosis (TB) is a major public health emergency in many countries, including Kazakhstan. Despite the decline in the incidence rate and having one of the highest treatment effectiveness in the world, the incidence rate of TB remains high in Kazakhstan. Social and environmental factors along with host genetics contribute to pulmonary tuberculosis (PTB) incidence. Due to the high incidence rate of TB in Kazakhstan, our research aimed to study the epidemiology and genetics of PTB in Kazakhstan. Materials and methods: 1,555 participants were recruited to the case-control study. The epidemiology data was taken during an interview. Polymorphisms of selected genes were determined by real-time PCR using pre-designed TaqMan probes. Results: Epidemiological risk factors like diabetes (χ2 = 57.71, p < 0.001), unemployment (χ2 = 81.1, p < 0.001), and underweight-ranged BMI (<18.49, χ2 = 206.39, p < 0.001) were significantly associated with PTB. VDR FokI (rs2228570) and VDR BsmI (rs1544410) polymorphisms were associated with an increased risk of PTB. A/A genotype of the TLR8 gene (rs3764880) showed a significant association with an increased risk of PTB in Asians and Asian males. The G allele of the rs2278589 polymorphism of the MARCO gene increases PTB susceptibility in Asians and Asian females. VDR BsmI (rs1544410) polymorphism was significantly associated with PTB in Asian females. A significant association between VDR ApaI polymorphism and PTB susceptibility in the Caucasian population of Kazakhstan was found. Conclusion: This is the first study that evaluated the epidemiology and genetics of PTB in Kazakhstan on a relatively large cohort. Social and environmental risk factors play a crucial role in TB incidence in Kazakhstan. Underweight BMI (<18.49 kg/m2), diabetes, and unemployment showed a statistically significant association with PTB in our study group. FokI (rs2228570) and BsmI (rs1544410) polymorphisms of the VDR gene can be used as possible biomarkers of PTB in Asian males. rs2278589 polymorphism of the MARCO gene may act as a potential biomarker of PTB in Kazakhs. BsmI polymorphism of the VDR gene and rs2278589 polymorphism of the MARCO gene can be used as possible biomarkers of PTB risk in Asian females as well as VDR ApaI polymorphism in Caucasians.

Vitamin D Status, VDR, and TLR Polymorphisms and Pulmonary Tuberculosis Epidemiology in Kazakhstan.

BACKGROUND: Tuberculosis (TB) and vitamin D deficiency remain major public health problems in Kazakhstan. Due to the high incidence of pulmonary tuberculosis in the country and based on the importance of vitamin D in the modulation of the immune response and the association of its deficiency with many health conditions, the aim of our research was to study the vitamin D status, VDR and TLR gene polymorphisms, and pulmonary tuberculosis epidemiology in Kazakhstan. METHODS: A case-control study included 411 individuals diagnosed with pulmonary TB and 686 controls with no family history of pulmonary tuberculosis. Concentrations of serum vitamin D (25-(OH)D) levels were measured by electrochemiluminescence immunoassay. The gene polymorphisms were determined by real-time polymerase chain reaction (PCR) allelic discrimination assay using TaqMan probes. The association between the risk of pulmonary TB and polymorphisms was evaluated using multimodal logistic regression and assessed with the ORs, corresponding to 95% Cis, and the significance level was determined as p < 0.05. RESULTS: 1097 individuals were recruited from 3 different regions of Kazakhstan. Biochemical data showed vitamin D deficiency (25-(OH)D < 20 ng/mL) was present in both groups, with the case group accounting for almost 95% and 43.7% in controls. Epidemiological data revealed that socioeconomic factors such as BMI < 25 kg/m2 (p < 0.001), employment (p < 0.001), diabetes (p < 0.001), and vitamin D deficiency (p < 0.001) were statistically different between case and control groups. Logistic regression analysis, adjusted by sex, age, BMI, residence, employment, smoking, alcohol consumption, and diabetes, showed that T/T polymorphism of the VDR gene (rs1544410, OR = 1.97, 95% CI: 1.04-3.72, p = 0.03) and A/A polymorphism of the TLR8 gene (rs3764880, OR = 2.44, 95% CI: 1.20-4.98, p = 0.01) were associated with a high risk of developing pulmonary tuberculosis. CONCLUSIONS: Vitamin D deficiency remains prevalent in our study cohort and is associated with TB progression. Socioeconomic determinants such as unemployment, BMI under 25 kg/m2, and diabetes are the main risk factors for the development of pulmonary TB in our study. A/A polymorphism of TLR8 (rs3764880) and T/T polymorphism (BsmI, rs1544410) of VDR genes may act as biomarkers for pulmonary tuberculosis in the Kazakh population.

Whole-Genome Sequence-Based Characterization of Pre-XDR M. tuberculosis Clinical Isolates Collected in Kazakhstan.

BACKGROUND: Kazakhstan has a high burden of multidrug-resistant tuberculosis in the Central Asian region. This study aimed to perform genomic characterization of Mycobacterium tuberculosis strains obtained from Kazakhstani patients with pre-extensively drug-resistant tuberculosis diagnosed in Kazakhstan. METHODS: Whole-genome sequencing was performed on 10 pre-extensively drug-resistant M. tuberculosis strains from different regions of Kazakhstan. All strains had high-confidence resistance mutations according to the resistance grading system previously established by the World Health Organization. The genome analysis was performed using TB-Profiler, Mykrobe, CASTB, and ResFinder. RESULTS: Valuable information for understanding the genetic diversity of tuberculosis in Kazakhstan can also be obtained from whole-genome sequencing. The results from the Phenotypic Drug Susceptibility Testing (DST) of bacterial strains were found to be consistent with the drug resistance information obtained from genomic data that characterized all isolates as pre-XDR. This information can help in developing targeted prevention and control strategies based on the local epidemiology of tuberculosis. Furthermore, the data obtained from whole-genome sequencing can help in tracing the transmission pathways of tuberculosis and facilitating early detection of outbreaks. CONCLUSIONS: The results from whole-genome sequencing of tuberculosis clinical samples in Kazakhstan provide important insights into the drug resistance patterns and genetic diversity of tuberculosis in the country. These results can contribute to the improvement of tuberculosis control and management programs in Kazakhstan.

Prevalence of Beijing Central Asian/Russian Cluster 94-32 among Multidrug-Resistant M. tuberculosis in Kazakhstan.

The Beijing genotype is the most distributed M. tuberculosis family in Kazakhstan. In this study, we identified dominant Beijing clusters in Kazakhstan and assessed their drug susceptibility profiles and association with the most widely spread mutation Ser531Leu of the rpoB gene and the mutation Ser315Thr of the katG gene associated with resistance to rifampicin and isoniazid, respectively. M. tuberculosis isolates (n = 540) from new TB cases were included in the study. MIRU-VNTR genotyping was performed for 540 clinical isolates to determine M. tuberculosis families using 24 loci. RD analysis was additionally performed for the Beijing isolates. The identification of mutations in the drug-resistance genes of M. tuberculosis was performed with allele-specific real-time PCR and Sanger sequencing. The Beijing genotype was identified in 60% (324/540) of the clinical isolates. Central Asian/Russian cluster 94-32 was the most distributed cluster among the Beijing isolates (50.3%; 163/324). Three other dominant Beijing clusters were identified as 94-33 (3.4%; 11/324), 100-32 (3.1%; 10/324) and 99-32 (3.1%; 10/324). The Beijing genotype was associated with drug-resistant TB (p < 0.0001), including multidrug-resistant TB (p < 0.0001), in our study. An association of the mutation Ser531Leu of the rpoB gene with the Beijing genotype was found (p < 0.0001; OR = 16.0000; 95%CI: 4.9161-52.0740). Among the Beijing isolates, cluster 94-32 showed an association with MDR-TB (p = 0.021). This is why the evaluation of the Beijing genotype and its clusters is needed to control MDR-TB in Kazakhstan.

Genomic Analysis of Multidrug-Resistant Mycobacterium tuberculosis Strains From Patients in Kazakhstan.

Tuberculosis (TB) is an infectious disease that remains an essential public health problem in many countries. Despite decreasing numbers of new cases worldwide, the incidence of antibiotic-resistant forms (multidrug resistant and extensively drug-resistant) of TB is increasing. Next-generation sequencing technologies provide a high-throughput approach to identify known and novel potential genetic variants that are associated with drug resistance in Mycobacterium tuberculosis (Mtb). There are limited reports and data related to whole-genome characteristics of drug-resistant Mtb strains circulating in Kazakhstan. Here, we report whole-genome sequencing and analysis results of eight multidrug-resistant strains collected from TB patients in Kazakhstan. Genotyping and validation of all strains by MIRU-VNTR and spoligotyping methodologies revealed that these strains belong to the Beijing family. The spectrum of specific and potentially novel genomic variants (single-nucleotide polymorphisms, insertions, and deletions) related to drug resistance was identified and annotated. ResFinder, CARD, and CASTB antibiotic resistance databases were used for the characterization of genetic variants in genes associated with drug resistance. Our results provide reference data and genomic profiles of multidrug-resistant isolates for further comparative studies and investigations of genetic patterns in drug-resistant Mtb strains.

Patients with coronary heart disease, dilated cardiomyopathy and idiopathic ventricular tachycardia share overlapping patterns of pathogenic variation in cardiac risk genes.

BACKGROUND: Ventricular tachycardia (VT) is a major cause of sudden cardiac death (SCD). Clinical investigations can sometimes fail to identify the underlying cause of VT and the event is classified as idiopathic (iVT). VT contributes significantly to the morbidity and mortality in patients with coronary artery disease (CAD) and dilated cardiomyopathy (DCM). Since mutations in arrhythmia-associated genes frequently determine arrhythmia susceptibility screening for disease-predisposing variants could improve VT diagnostics and prevent SCD in patients. METHODS: Ninety-two patients diagnosed with coronary heart disease (CHD), DCM, or iVT were included in our study. We evaluated genetic profiles and variants in known cardiac risk genes by targeted next generation sequencing (NGS) using a newly designed custom panel of 96 genes. We hypothesized that shared morphological and phenotypical features among these subgroups may have an overlapping molecular base. To our knowledge, this was the first study of the deep sequencing of 96 targeted cardiac genes in Kazakhstan. The clinical significance of the sequence variants was interpreted according to the guidelines developed by the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) in 2015. The ClinVar and Varsome databases were used to determine the variant classifications. RESULTS: Targeted sequencing and stepwise filtering of the annotated variants identified a total of 307 unique variants in 74 genes, totally 456 variants in the overall study group. We found 168 mutations listed in the Human Genome Mutation Database (HGMD) and another 256 rare/unique variants with elevated pathogenic potential. There was a predominance of high- to intermediate pathogenicity variants in LAMA2, MYBPC3, MYH6, KCNQ1, GAA, and DSG2 in CHD VT patients. Similar frequencies were observed in DCM VT, and iVT patients, pointing to a common molecular disease association. TTN, GAA, LAMA2, and MYBPC3 contained the most variants in the three subgroups which confirm the impact of these genes in the complex pathogenesis of cardiomyopathies and VT. The classification of 307 variants according to ACMG guidelines showed that nine (2.9%) variants could be classified as pathogenic, nine (2.9%) were likely pathogenic, 98 (31.9%) were of uncertain significance, 73 (23.8%) were likely benign, and 118 (38.4%) were benign. CHD VT patients carry rare genetic variants with increased pathogenic potential at a comparable frequency to DCM VT and iVT patients in genes related to sarcomere function, nuclear function, ion flux, and metabolism. CONCLUSIONS: In this study we showed that in patients with VT secondary to coronary artery disease, DCM, or idiopathic etiology multiple rare mutations and clinically significant sequence variants in classic cardiac risk genes associated with cardiac channelopathies and cardiomyopathies were found in a similar pattern and at a comparable frequency.

Whole genome sequence data of Mycobacterium tuberculosis XDR strain, isolated from patient in Kazakhstan.

Drug-resistant tuberculosis (TB) is a major public health problem. Clinical Mycobacterium tuberculosis (MTB) isolate with Extensively drug-resistant tuberculosis (MTB-XDR) profile was subjected to whole-genome sequencing using a next-generation sequencing platform (NGS) Roche 454 GS FLX+ followed by bioinformatics sequence analysis. Quality of read was checked by FastQC, paired-end reads were trimmed using Trimmomatic. De novo genome assembly was conducted using Velvet v.1.2.10. The assembled genome of XDR-TB-1599 strain was functionally annotated using the PATRIC platform. Analysis of de novo assembled genome was performed using ResFinder, CARD, CASTB and TB-Profiler tools. MIRU_VNTR genotyping on 12 loci and spoligotyping have been performed for XDR-TB-1599 isolate. M. tuberculosis XDR-TB-1599 strain yielded an average read depth of 21-fold with overall 4 199 325 bp. The assembled genome contains 5528 protein-coding genes, including key drug resistance and virulence-associated genes and GC content of 65.4%. We identified that all proteins encoded by this strain contain conserved domains associated with the first-line anti-tuberculosis drugs such as rifampicin, isoniazid, streptomycin and ethionamide. TB-Profiler had higher average concordance results with phenotypic DST (drug susceptibility testing) in comparison with ResFinder, CARD, CASTB profiling to first-line (75% vs 50%) and second-line (25% vs 0%) of anti-TB drugs, correspondingly. To our knowledge, this is the first report of a highly annotated and characterized whole-genome sequence and de novo assembled XDR-TB M.tuberculosis strain isolated from a sputum of new TB case-patient from Kazakhstan performed on Roche 454 GS FLX+ platform. This report highlights an important role of whole-genome sequencing technology and analysis as an advanced approach for drug-resistance investigations of circulated TB isolates.

Draft Genome Sequences of Two Clinical Isolates of Mycobacterium tuberculosis from Sputum of Kazakh Patients.

Here, we report the draft genome sequences of two clinical isolates of Mycobacterium tuberculosis (MTB-476 and MTB-489) isolated from sputum of Kazakh patients.

Distribution of Beijing Genotype Among Clinical Isolates of M. tuberculosis Circulating in Kazakhstan.

INTRODUCTION: Methods of genotyping of M. tuberculosis play an important role in tuberculosis (TB) infection control. These techniques are used to detect or exclude laboratory errors, control recurrent cases, and determine ways of TB transmission. Today, there are more than 10 methods of genotyping; MIRU-VNTR is one of the most widely used methods in the world. In this study we aimed to estimate biological diversity of clinical isolates of M. tuberculosis from different regions of Kazakhstan based on MIRU-VNTR analysis. MATERIALS AND METHODS: MIRU-VNTR was used to genotype 134 clinical isolates of M. tuberculosis isolated from new cases and recurrent cases of TB from different regions of Kazakhstan. Amplification was done using 15 MIRU-VNTR loci. Determination of the number of tandem repeats in the corresponding locus was performed via Quantity One v.4.4.0 (BioRad, USA) software. H37Rv (NC_000962) reference strain was used as a positive control. RESULTS: Phylogenic tree was built using www.miru-vntr.org web-resource based on the results of MIRU-VNTR analysis. Beijing family strains associated with drug resistance to antituberculosis drugs were prevalent among all isolates of M. tuberculosis circulating in Kazakhstan. Strains of the Beijing genotype were prevalent in both new cases (65%) and recurrent cases (89.4%) of tuberculosis. The second meaningful genotype that is spread in the territory of Kazakhstan is LAM, the frequency of distribution is 7.3% in new and 4.5% in recurrent cases. Other families of M. tuberculosis such as Ural, Haarlem, CAS, NEW-1, S were found in less than 4% of cases. CONCLUSION: Prevalence of Beijing family strains among all isolates of M. tuberculosis from different regions of Kazakhstan was shown. Strains of this family are prevalent among young people. This genotype is responsible for ongoing TB transmission in the present time. This genotype is more virulent; therefore, investigation of the epidemiology of the Beijing genotype plays crucial role in the monitoring of tuberculosis.

Molecular characterization of rifampicin- and isoniazid-resistant Mycobacterium tuberculosis strains isolated in Kazakhstan.

Kazakhstan is one of the 14 countries with a high rate of morbidity due to multidrug-resistant tuberculosis (MDR TB) in WHO European region. The aim of our study was to characterize mutations associated with drug resistance to rifampicin and isoniazid in Mycobacterium tuberculosis isolates from Kazakhstan. M. tuberculosis strains were isolated from TB patients in different regions of Kazakhstan. A drug susceptibility test was performed on Lowenstein-Jensen medium using the absolute concentration method. Sequencing analysis was performed of the rpoB rifampicin resistance-determining region and the katG gene, the oxyR-ahpC intergenic region, and the inhA promoter region in 259 MDR M. tuberculosis isolates, in 51 isoniazid-resistant isolates, and in 13 rifampicin-resistant isolates. The mutational analysis revealed that the most frequent mutations associated with rifampicin and isoniazid resistance in M. tuberculosis are the substitutions at codons 531 (82.7%) and 315 (98.4%) in the rpoB and katG genes, respectively. In addition, we have found mutations with lower frequency at codon 526 (8.4%), 533 (1.5%), and 516 (1.1%) in the rpoB gene. In 6.2% of the isolates, no mutations were found in the rpoB gene. The findings of this study provide useful data for a better understanding of the mutation spectrum of isoniazid and rifampicin resistance among strains isolated from patients in Kazakhstan. Our results are also useful for the development of diagnostic tests of MDR M. tuberculosis.