Comparison of the effectiveness of solid nutrient medium in the in vitro cultivation of Neisseria gonorrhoeae isolates

Background. Neisseria gonorrhoeae is a facultatively anaerobic microorganism which is extremely demanding to the composition of a nutrient media and cultivation conditions. In a situation of the increasing shortage and cost of foreign components for the preparation of solid nutrient media, it is important to study the possibility of growing hard-to-cultivate microorganisms on domestically produced nutrient media.The aim of the study. To evaluate the growth of gonococcus colonies on two types of solid nutrient media – chocolate agar with growth and selective additives prepared using imported reagents and chocolate agar with growth additives manufactured by “Gem LTD” (Moscow, Russian Federation).Materials and methods. А reference strain of N. gonorrhoeae NCTC 12700/ ATCC 49226 and two types of chocolate agar (the first one – prepared in the State Scientific Center of Dermatovenerology and Cosmetology using imported components and the other one – from the domestic manufacturer “Gem LTD”) were used in the research.Results. The equivalence of the growth properties of both studied types of nutrient media when cultivating pure gonococcus was revealed.Conclusions. Ready-to-use chocolate agar with growth additives produced by “Gem LTD” can be successfully used in the laboratory for the cultivation of N. gonorrhoeae pure culture. Primary isolation of N. gonorrhoeae strains from clinical material is more appropriate to carry out on a medium that suppresses the growth of foreign microflora due to the inclusion of antibiotic additive. The organization of production of domestic bacteriological media for microorganisms with high nutrient requirements reduces the dependence of domestic microbiology on import and ensures their rapid delivery to laboratories

Comparative Analysis of the Sequenced Zaire ebolavirus Samples from the Republic of Guinea

An unprecedented on its scale Ebola fever epidemic, caused by Zaire ebolavirus, has been registered in the territory of West Africa in 2014-2015. The virus quickly spread from the Republic of Guinea into the neighboring countries. Presented are the results of comparative analysis between three Zaire ebolavirus genomes, the complementary DNA of which was obtained from the samples from Ebola fever patients in the Republic of Guinea in 2014. The nucleotide sequences of the genomes received have allowed for identification of phylogenetic affinity to certain references, displayed in the database of NCBI GenBank. General phylogenetic analysis by means of representative sampling has revealed two trends of genome evolutionary development from one and the same ancestral form. The first branch of evolution is represented by a relatively small number of Zaire ebolavirus isolates, disseminated in Guinea. The second one, the most numerous trend, is generated by four variants of Zaire ebolavirus genome, which have been identified starting from May - early June, 2014 in Sierra-Leone, but within a short period of time they have won the whole territory of the country and the neighboring Guinea and Liberia

Phenotypic and Molecular-Genetic Peculiarities of Yersinia pestis Strains from Trans-Baikal Steppe Plague Focus

The paper contains the data on the complex phenotypic and genotypic characteristics of Yersinia pestisstrains isolated in Trans-Baikal steppe plague focus before and after the succession of the main carrier which took place in the 1960s. Based on the PCR-analysis and multilocus sequence typing of glpD, melB, napA, rhaA, and iclR genes, encoding differentially significant properties such as glycerin, melibiose, rhamnose fermentation, isocitrate lyase production, and denitrification activity, developed are the proofs of affiliation of the studied strains to the biovariant antiqua of the plague agent main subspecies. Multilocus VNTR-analysis by seven locuses of variable tandem repeats – ms01, ms04, ms06, ms07, ms46, ms62 – has been used to establish genetic relations between the strains. Thus on the basis of the results obtained, it is established that the strains of the plague agent, isolated in the Trans-Baikal steppe focus in various periods of its existence, form one common branch on the phylogenetic tree of Y. pestis evolution

Phylogenetic Analysis of <i>Yersinia pestis</i> Strains of Medieval Biovar from Natural Plague Foci of the Russian Federation and Bordering Countries

Objective of the study is to conduct phylogenetic investigation of Yersinia pestis strains (medieval biovar) from plague foci of Russia and bordering countries, using SNP-analysis of the genome-wide sequences of these strains. Materials and methods. Carried out has been sequencing of 14 Y. pestis strains, medieval biovar, from 13 natural plague foci of Russia and neighboring states, as well as their comparison to 9 strains of the same biovar, contained in the NCBI GenBank database. Using software products - Wombac 2.0 and Bionumerics 7.1, revealed is the presence of 1875 core SNPs, on the basis of which a dendrogram of phylogenetic relations between medieval strains is constructed. Results and conclusions. In consequence of genome-wide SNP-analysis, it is established that Y. pestis strains, medieval biovar, from plague foci of Russia and bordering states are assigned to 2.MED1 phylogenetic line and fall under two major evolutionary branches, the first one of which includes strains from the Caucasus and Caspian-Sea regions, and the second one - from Central Asia and China. The data obtained can be used for the development of molecular-genetic methods for differentiation of Y. pestis strains, medieval biovar

Molecular-Genetic and Phenotypic Peculiarities of Plague Agent Strains Isolated in Vietnam

Objective of the study is to investigate phenotypic and molecular-genetic features and perform whole genome sequencing of Y. pestis strains isolated in Vietnam. Materials and methods. Studied were phenotypic and genotypic peculiarities of 20 plague agent strains isolated in different prefectures of Vietnam. Carried out was SNP-analysis of the strains, sequenced were genomes of 8 Y. pestis strains. Results and conclusions. Based on the results of studies of differential biochemical characteristics all the investigated strains were attributed to oriental biovar of the main subspecies of plague agent, which was confirmed by the presence of marker indel mutation – deletion of 93 bps in glpD gene. Investigated was also the plasmid composition of the strains. On the basis of the conducted genome sequencing and SNP-analysis appurtenance of 19 out of 20 strains under examination was determined. They belong to 1.ORI2v phylogenetic branch, relative to the strains isolated in Yunnan Province, China, which points to their common origin. Identified was a marker SNP and developed the method of SNP-typing for 1.ORI2v strains from Vietnam

Updating of Intra-Specific <i>Yersinia pestis</i> Classification, Based on the Results of Whole-Genome Sequencing of the Strains from the Russian Federation and the Neighboring States

Carried out has been genome-wide sequencing of 20 Yersinia pestis strains from all 11 natural plague foci in Russia and some foci in the neighboring states. Phylogenetic analysis on the basis of 1918 core SNPs, identified in the genomes of these strains and 16 Y. pestis strains from NCBI GenBank, has revealed 5 clusters of closely related strains. Taking these clusters into account, up-dated has been subspecific classification of plague agent. New taxonomy has combined 5 subspecies: major (ssp. pestis ), Caucasian (ssp. caucasica ), ulegeisk (ssp. ulegeica ), and two novel ones - Central Asian (ssp. central asiatica ) and Angolan (ssp. angola ). Central Asian subspecie comprises evolutionally related strains, earlier classified as altaica and hissarica, as well as the strains from Talas high-mountain focus in Kirghizia and Uzbekistan, and microtus strains from China. Central asiatica is divided into three biovars - altai, hissar, and microtus. Set forward is a serviceable designation for the strains: 0.PE4a - for altai ones, 0.PE4h - for hissar, 0.PE4t - for talas, and 0.PE4m - for microtus, and also for ulegeica subspecie - 0.PE5

Evaluation of Effectiveness of Yersinia pestis Molecular Diagnostics in the Field Material from Sarydzhas Focus in Kyrgyzstan

Objective of the study is to assess the effectiveness of the methods for molecular diagnostics and identification of Yersinia pestis strains in the field material obtained from Sarydzhas high-mountain focus in Kyrgyz Republic. Materials and methods. Investigated were the samples of the field material, isolated in 2016 in Sarydzhas high-mountain plague focus, using conventional methods of laboratory diagnostics and PCR with hybridization-fluorescent and electrophoretic registration of results. Results and conclusions. It is demonstrated that in a number of cases molecular-genetic method has a higher resolution as compared to conventional methods of laboratory diagnostics of plague. It proves the necessity of wider usage of molecular-diagnostic methods in epizootiological monitoring of plague in natural foci in Kyrgyz Republic

SOME FEATURES OF CURRENT TECHNOGENIC MOVEMENTS OF THE EARTH’S CRUST

We describe the history of studying the current crustal movements by various methods and discuss technogenic effects recorded at large water-reservoir zones and mineral deposits in Siberia. Initially, classical surveying techniques aimed to obtain high-accuracy ground-based measurements of height, tilt and direction. Modern geodesy techniques and methods for measuring absolute gravity are now available to investigate displacement, deformation, tilt and other phenomena taking place on the Earth’s surface. These methods are used to estimate kinematic parameters of the crust areas (e.g. rates of subsidence and horizontal movements) and to monitor fluid motions in mineral deposits. Such data are critical for ensuring a proper management of the mineral deposits. In this article, we analyse technogenic processes observed in the Ust Balyk oil-gas field, the Zapolyarny gas deposit, the water-reservoir zone at the Sayano-Shushenskaya hydroelectric power station (SSHPS) on the Yenisei river, and large open-pit mines in the Kuzbass basin. Our analysis is based on surface displacement rates estimated from the data collected in different periods of observations at large man-made facilities. In the study of the hydro technical objects, we estimated the displacement rates at 5.0 mm per year. In the northern areas of the West Siberian petroleum basin, subsidence rates amounted to 20–25 mm per year in the early 2000s. These estimates were supported by the high-accuracy gravity measurements showing an increase up to 6–7 microGal per year in the oil-gas field development areas. We assess a possibility of triggering effects related to weak seismicity due to a high stress accumulation rate (1 KPa per hour) in the SSHPS area. A connection between earth tides and catastrophic events, such as gas emissions in high amounts on mining sites, is discussed. Having analysed the surface monitoring records taken in South Primorye in September 2017, we conclude that underground nuclear explosions in North Korea in this period did not cause any significant displacement of the surface in this most southerly region of the Russian Far East territories

Fast optical variability of SS 433

We study the optical variability of the peculiar Galactic source SS 433 using the observations made with the Russian Turkish 1.5-m telescope (RTT150). A simple technique which allows to obtain high-quality photometric measurements with 0.3-1 s time resolution using ordinary CCD is described in detail. Using the test observations of nonvariable stars, we show that the atmospheric turbulence introduces no significant distortions into the measured light curves. Therefore, the data obtained in this way are well suited for studying the aperiodic variability of various objects. The large amount of SS 433 optical light curve measurements obtained in this way allowed us to obtain the power spectra of its flux variability with a record sensitivity up to frequencies of ~0.5 Hz and to detect its break at frequency =~2.4e-3 Hz. We suggest that this break in the power spectrum results from the smoothing of the optical flux variability due to a finite size of the emitting region. Based on our measurement of the break frequency in the power spectrum, we estimated the size of the accretion-disk photosphere as 2e12 cm. We show that the amplitude of the variability in SS 433 decreases sharply during accretion-disk eclipses, but it does not disappear completely. This suggests that the size of the variable optical emission source is comparable to that of the normal star whose size is therefore R_O \approx 2e12 cm \approx 30 R_sun. The decrease in flux variability amplitude during eclipses suggests the presence of a nonvariable optical emission component with a magnitude m_R=~13.2.Comment: 12 pages, 11 figures. Accepted for publication in Astronomy Letters. The original version in Russian is available at http://hea.iki.rssi.ru/rtt150/ru/ss433_pazh10/pss433_fast.pd

Потенциальные биомаркеры эффективности терапии ниволумабом при метастатическом почечно-клеточном раке

Background. Therapy with immune checkpoint inhibitors (antibodies against PD-1) has become a standard of treatment of patients with metastatic renal cell carcinoma (mRCC) resistant to tyrosine kinase inhibitors. Objective: to identify reliable immunological markers predicting mRCC sensitivity to nivolumab therapy to increase its effectiveness and facilitate its more rational application.Materials and methods. The article presents an analysis of treatment of 23 patients with mRCC who received nivolumab under the expanded access program. Objective response rate in this group was 21.7 %. Median progression-free survival was 4 months (95 % confidence interval was 1.37–10.04). Median overall survival wasn’t reached for median follow-up duration of 10 months (3–14 months); grade III–IV complications were observed in 13 % of cases.Results. During nivolumab therapy, factors positively affecting progrerssion-free survival were presence of clinical effect, favorable prognosis per the Memorial Sloan Kettering Cancer Center criteria, development of hypothyroidism, baseline serum levels of interleukin-17А and sPD-1 above the threshold values. Baseline increased serum concentration of TGF-β1 compared to the threshold level (20 ng/ml) was a negative prognostic factor for nivolumab immunotherapy. The number of previous therapy lines, PD-L1 and FOXP3 expression on tumor-infiltrating lymphocytes didn’t significantly affect progression-free survival. Effectiveness and toxicity profile of nivolumab in this series of observations conformed to the results of the phase III clinical trial. The drug was characterized by high tolerability.Conclusion. The study results demonstrated lower toxicity and high tolerability of nivolumab compared to previously registered targeted drugs. Low rate of adverse events allows to study nivolumab in combined or subsequent/alternating modes of treatment with other immune checkpoint inhibitors and targeted drugs.Введение. Терапия ингибиторами контрольных точек иммунного ответа (антителами к PD-1) стала стандартом лечения больных метастатическим почечно-клеточным раком (мПКР), резистентных к тирозинкиназным ингибиторам.Цель исследования – идентификация надежных иммунологических маркеров, предсказывающих чувствительность мПКР к иммунотерапии ниволумабом, что способствовало бы повышению ее эффективности и более рациональному использованию.Материалы и методы. В статье представлен анализ результатов лечения 23 пациентов с мПКР, получавших ниволумаб в рамках программы расширенного доступа к препарату. Частота объективного ответа в данной группе составила 21,7 %. Медиана выживаемости без прогрессирования составила 4 мес (95 % доверительный интервал 1,37–10,04). Медиана общей выживаемости не достигнута при медиане времени наблюдения 10 мес (3–14 мес), осложнения III–IV степени были отмечены в 13 % случаев.Результаты. При проведении иммунотерапии ниволумабом факторами, благоприятно влияющими на выживаемость без прогрессирования заболевания, стали наличие клинического эффекта, благоприятный прогноз согласно критериям Memorial Sloan Kettering Cancer Center, развитие гипотиреоза, исходные уровни интерлейкина-17А и sPD-1 в сыворотке крови, превышающие пороговые значения. Отрицательным прогностическим фактором при проведении иммунотерапии ниволумабом стала исходно повышенная концентрация в сыворотке крови TGF-β1 по сравнению с пороговым уровнем (20 нг / мл). Число предшествующих линий терапии, экспрессия PD-L1 и FOXP3 на инфильтрирующих опухоль лимфоцитах не оказали достоверного влияния на выживаемость без прогрессирования. Эффективность и токсический профиль ниволумаба в данной серии наблюдений соответствовали результатам III фазы клинического исследования. Препарат отличался хорошей переносимостью.Заключение. Результаты исследования показали более низкую токсичность и хорошую переносимость ниволумаба по сравнению с таргетными препаратами, зарегистрированными ранее. Невысокая частота побочных эффектов позволяет изучать ниволумаб в комбинированных или последовательных / альтернирующих режимах с другими ингибиторами иммунных контрольных точек и таргетными препаратами