Mongolia and Russia are among the countries with the high tuberculosis (TB) burden. The prevalence of tuberculosis, including multidrug-resistant tuberculosis (MDR), in Eastern Siberia bordering ...Mongolia is significantly higher than in the European part of Russia. In addition, unlike Mongolia, Eastern Siberia is characterized by a high prevalence of HIV infection. The cross-border spread of socially significant infections in these countries seems to occur due to their wide-range cooperation and cultural exchange. Whereas the HIV infection has no epidemiological significance for Mongolia at the moment, tuberculosis, however, has a similar prevalence on both sides of the border. The aim was to evaluate the cross-border MDR M. tuberculosis distribution in Mongolia and Eastern Siberia by using molecular genetic data. Materials and methods. A total of 1045 M. tuberculosis strains isolated in Mongolia (291) and the three regions of Eastern Siberia (754) were studied by using the MIRU-VNTR-24 loci genotyping. The CC2/W148 and CC1 subtypes were identified by the specific deletion in the kdpD gene and SNP in the pks17 gene at position 1887060, respectively. Phylogenetic analysis of MIRU-VNTR patterns was carried out by generating UPGMA tree and maximum likelihood tree. Results. The Beijing genotype was found in 75.3% (219/291) and 69.0% (520/754) from Mongolian and East Siberian collection, respectively. Common minor genotypes were LAM (11.0% and 15.1%), T (10.3% and 4.5%), and Haarlem (1.4% and 2.4%) found in Mongolia and Eastern Siberia, respectively. The genotypes S (1.3%) and Ural (5.0%) were found solely in the Russia-derived samples. The main epidemic Beijing subtypes in each country belonged to different clonal complexes (CC): the majority of Mongolian Beijing strains displayed profiles 342-32, 3819-32, 1773-32 MLVA types and belonged to the CC4 subtype; Russian Beijing strains mainly belonged to the CC1 (43.7% — 227/520) and CC2/W148 (34.8% — 181/520) subtypes. The MDR level and distribution patterns differed significantly between Mongolia and Eastern Siberia. Modeling of Beijing strain expansion evidences about extremely subtle contribution of the M. tuberculosis cross-border transmission between Mongolia and Russia. The phylogenetic reconstruction of Beijing CC4 subtype evolution in Mongolia suggests that its distribution is primarily associated with China and other countries of the Western Pacific Region. Three main phylogenetic branches of CC4 subtype were traced, which probably spread throughout Mongolia in the 11—12th centuries. It may be assumed that spreading of the epidemic Beijing CC4 subtype might occur in two stages: early period — emergence of ancestral CC4 variants in Mongolia or their introduction from China (they are homologous to the strains preserved in the Chinese population), later period — dissemination due to the active exchange of M. tuberculosis with countries of Southeast Asia, but not Russia. Conclusion. Using MIRU-VNTR-24 genotyping as well as classification according to specific single nucleotide polymorphisms specific to certain Beijing subtypes, it allowed to describe separate patterns of the epidemic variants spread in Mongolia and Russia. It has been demonstrated that emergence and spread of MDR-TB in Mongolia are entirely iatrogenic in nature, while the epidemic subtypes of the Beijing genotype (subtypes CC1 and CC2/W148) contribute markedly into the MDR-TB spreading in Eastern Siberia.
Relevance.
The globalization of the epidemic process requires improved surveillance of infectious diseases, in particular tuberculosis.
Methods
of molecular and genomic analysis are the most ...informative approaches that can radically change the management of this disease.
Aims.
To substantiate the necessary and sufficient volume of molecular studies for the exhaustive detection of most epidemic genotypes of Mycobacterium tuberculosis in Russia and the countries of the former USSR.
Conclusions.
Genetic lines L2 (Beijing) and L4 (Euro-American) cover more than 95% of all epidemic genotypes of M. tuberculosis in Russia and the countries of the former USSR. The development of rapid tests compatible with global data on genomic polymorphism will make it possible to conduct an epidemiological analysis of tuberculosis outbreaks within the country and to differ from cases of transbordern transmission of new genotypes outside.
The 21st century is characterized by the exacerbation of the problem formation and spreading of drug-resistant strains throughout the world. Genetic mutations of Mycobacterium tuberculosis lead to ...the formation of drug-resistant forms because of long-term use of anti-tuberculosis drugs. The Russian Federation is among the top three countries with a high burden of tuberculosis with multidrug resistance (MDR). The estimated number of cases of tuberculosis with MDR in the Russian Federation was 60,000, which corresponds to half the burden of the European Region in 2015. In the Irkutsk region from 2014 till 2018 the proportion of TB cases with MDR cases increased from 15.2 % to 18.3 %. According to the reference laboratory of the Irkutsk Regional Clinical Tuberculosis Hospital, a significantly higher level of MDR among primary diagnosed was registered in the cities (27.7 %) and the lowest in rural areas of the region (16.5 %). Among the cohorts of patients with tuberculosis, the highest proportion of MDR was in the northern territories of the region (43.1 %), in Irkutsk district (41.2 %) and in large cities, including Irkutsk (38.5 %). Positive correlations were established between cohort of primary diagnosed TB with MDR and among populations in areas with high morbidity along the railway (r = 0.91; p = 0.00001), in the Irkutsk region (r = 0.89; p = 0,00008), and also in the Irkutsk city (r = 0.91; p = 0.00002). This is probably due to the influence of reservoir of tuberculosis infection formed in these localities. The regulatory documents of the Ministry of Health of the Irkutsk Region was developed on the basis of the data obtained, and they include recommendations for improving the diagnosis of tuberculosis in the region using fast and accelerated microbiological diagnostic methods.
Relevance. The heterogeneity of the epidemic cluster B0/W148 in Russia is described for the first time. Aim of investigation was to create an epidemic model of tuberculosis strains B0/W148 spreading ...in Siberian Federal District (SFD) and Far Eastern Federal District (FEFD) and to identify the genetic relationship between the studied strains. Results and discussion. A comparative study of single nucleotide polymorphism (SNP) distribution in genomes of 20 strains from the SFD and FEFD and similar data in 62 strains from other regions of Russia was carried out. Based on Bayesian phylogenetic analysis was proposed epidemiological model of the emergence and spread of highly transmissible strains the B0/W148 cluster of M. tuberculosis in Russia. Siberian and Yakutian subclusters were identified and characterized by the simulation results.
Background.
The viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the new coronavirus infection, is becoming increasingly important in clinical and ...epidemiological contexts. Despite this, there are significant complexities in the implementation of viral load quantitative measurement into clinical practice due to the limited approaches to its assessment.
The aim of this work
was
to
develop
an approach for SARS-CoV-2 viral load analysis by the value of sample threshold cycles (Ct) relative to the Ct of the internal control sample obtained in routine PCR diagnostics of the COVID-19, and to use this approach for quantitative monitoring of viral load in patients with first positive SARS-CoV-2 test from the Irkutsk region.
Materials
and methods.
Using regression models based on the least squares method, an approach to determine the number of copies of SARS-CoV-2 RNA in 1 ml of nasopharyngeal secretion was developed. The viral load of SARS-CoV-2 was assessed in nasopharyngeal and pharyngeal samples obtained from 1370 patients from Irkutsk and Angarsk with primary diagnosed positive PCR result in the period from July 1 to November 10, 2020.
Results.
A tenfold increase in the average monthly viral load among patients in September-October 2020 was revealed. We assume that the change in the epidemiological pattern of the spread of the new coronavirus infection during this period is associated with an increase in the number of contacts in the population due to the school year beginning. Higher viral loads are observed in populations at risk for COVID-19 – among healthcare workers and adults/elderly patients.
Conclusion.
The development of a standardized
quantification of SARS-CoV-2 viral load in the nasopharyngeal samples can be a predictive clinical marker and a reliable tool for improving COVID-19 surveillance using the proposed approach to assess average viral load in a local population.
Background.
The Far East is the territory with high rate of incidence and prevalence of tuberculosis. Cases of tuberculosis caused by epidemic strains have high frequency of MDR and XDR. It is ...important to study the prevalence of TB in areas with a high burden of infection, to which the Far East belongs. The aim of the research is to carry out genotyping of strains and assess the prevalence of CC1 and CC2 subtypes in the territory of Primorsky Krai.
Materials and methods.
The DNAs of 99 clinical isolates of MBT from Primorsky Krai have been genotyped by the 24-locus MIRU-VNTR and RD105/RD207.
Results.
The dominant number of strains pertained to Beijing genotype (59.6 %). The express method revealed 22 isolates of the CC2/W148 subtype, which had 6 different MIRU-VNTR-24 profile. According to MLVA classification MtbC 15-9, the most common among the isolates of CC2/W148 profile is 100-32 (59.1 %). Among these profiles the highest frequency of MDR/XDR was recorded – 69,2 %. According to the results of the express analysis, 39 isolates with 26 different MIRU-VNTR-24 profiles belonged to the CC1 subtype, of which the dominant number belonged to 99-32 and 94-32.
Conclusions.
The methods of express genotyping of epidemic subtypes of the Beijing genotype are very important for epidemiological surveillance and clinical practice. The developed methods allow to define a wider range of strains than previously used methods.
Bacteria provide plants with additional resistance to adverse environmental factors, such as the lack of soil nutrients, anthropogenic pollution, the presence of phytopathogens, etc. The search for ...valuable biotechnological strains should be conducted among microorganisms associated with plants growing under unfavorable conditions. The present study aims to isolate and characterize microorganisms inhabiting the endo- and rhizosphere of Hedysarum zundukii, a local endemic of the Olkhon region (Olkhonsky District, Irkutsk Oblast). A total of 88 microbial strains were isolated, with Gram-positive microorganisms predominating in both the rhizo- and endosphere. In the rhizosphere, the vast majority of strains were found to belong to actinomycetes. Of the 25 identified isolates, four belong to the Rhizobiaceae family. The Phyllobacterium zundukense rhizobacterium was previously described as part of the microbiome of root nodules in Oxytropis triphylla also growing in this region. Its detection in the rhizosphere soil of H. zundukii suggests that this microorganism is associated with different legume species rather than with a single host. Of particular interest are the strains of Actinomycetia, as well as Lysobacter sp. and Variovorax paradoxus, which are promising for further study as producers of biologically active compounds, stimulators of plant growth and development, or pollutant degraders. Thus, isolates from both the rhizosphere and endosphere of H. Zundukii may possess traits useful for biotechnology and require further study.
Aim of the research
.
To study the epidemic manifestations of HCV infection in the Republic of Sakha (Yakutia) in order to develop recommendations for improving the effectiveness and quality of ...treatment and prevention measures.
Materials and methods
.
The paper uses materials from the official statistics of the Territorial Department of Rospotrebnadzor of the Republic of Sakha (Yakutia) for 1994–2018, and data from the electronic register «Chronic viral hepatitis
in the RS (Ya)» (2019). Molecular and biological studies of the genotype of the hepatitis C virus were performed jointly
on the basis of the Federal state budgetary Institution «Central research Institute of epidemiology» of Rospotrebnadzor
(2007–2011, n = 75). To assess the epidemiological situation, the rate of increase in morbidity is calculated on the basis
of data equalized by the method of least squares. Statistical processing was performed using the SPSS 17 program.
The critical significance level is assumed to be 0.05.
Results.
Thus, the study of long-term dynamics of the incidence of viral hepatitis shows that in the Republic of Sakha
(Yakutia) a consistently high level of incidence of HCV with adverse trends in the development of the epidemic process
remains. Analysis of the distribution of different variants of HCV genotypes allowed us to establish the prevalence
of genotype 1b, which can determine the high frequency of cirrhosis and primary liver cancer. The current situation
in the Republic regarding the incidence of viral hepatitis requires detailed monitoring, improvement of epidemiological surveillance and introduction of modern treatment methods. It is also necessary to improve the quality of health
education among the population of the Republic.
Relevance. In 2016, a resolution was adopted at the 69th World Health Assembly, the goal of which is to eliminate parenteral hepatitis in the world by 2030. In the Republic of Sakha (Yakutia), as in ...the Russian Federation as a whole, it is necessary to determine the starting positions for the prevalence and incidence of hepatitis B, C, and D, as the leading factors in the development of hepatocellular carcinoma. Aim: to give a clinical and epidemiological characterization of hepatocellular carcinoma in the Republic of Sakha (Yakutia) at the initial stage of the program for the elimination of viral hepatitis for subsequent analysis of its effectiveness. Materials & Methods. A clinical and epidemiological analysis of morbidity, mortality, cumulative survival in hepatocellular carcinoma in the Republic of Sakha (Yakutia) over a 10-year period (2009-2018) was carried out. Predictors for the development of hepatocellular carcinoma were analyzed based on primary medical records and a survey of 125 patients. Results and discussion. The incidence rate of hepatocellular carcinoma in the Republic of Sakha (Yakutia) over the past 10 years is 2.0 3.9 times higher than the corresponding indicator in the Russian Federation. The highest mortality from the studied pathology is noted in the Central and Polar zones of the republic. According to the materials of the cancer registry, the median cumulative survival of patients with carcinoma was 13.7 months from the date of diagnosis, which is significantly higher than ten years ago. The main risk factors have been identified, among which the leading role is played by infection with hepatitis C, B, and D. viruses. Also, alcohol abuse, diabetes mellitus, overweight, and smoking are important. Conclusion. The Republic of Sakha (Yakutia) is a hyperendemic region of the Russian Federation in terms of the incidence of hepatocellular carcinoma with a predominance of the male population in its structure. The rate of decrease in the incidence of liver cancer in the country will depend on the effectiveness of the regional program for the elimination of viral hepatitis and the decrease in the incidence of cirrhosis of the liver of non-infectious etiology.
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