58 research outputs found

    Data on the distribution of the <i>Haemaphysalis concinna</i> tick in the Irkutsk region and the Republic of Buryatia

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    The ixodid tick Haemaphysalis concinna (Koch, 1844) is a carrier of pathogens of vector-borne diseases of viral, bacterial and protozoal etiology. This tick was previously considered an adventive relict species in the Baikal region, but has recently shown a tendency to increase its numbers and expand its habitat. The aim of the study. To generalize the available and newly received information on the distribution of the H. concinna tick in the Irkutsk region and the Republic of Buryatia; to carry out the comparative analysis of the results in order to identify the dynamics of the development of populations of this species of ixodid ticks in the Baikal region. Materials and methods. The coordinates of H. concinna detection points in our studies were obtained using a GPS navigator directly in the field. Ticks were caught during the period of their maximum activity from plants using a flannel flag. Approximate geographic coordinates of H. concinna tick detection points were established when analyzing the maps published by other researchers. Results. As a result of the generalization of our own data and data from literary sources, 52 georeferenced detection points of H. concinna were obtained on the territory of the Baikal region. A map showing the distribution of H. concinna in the territory of the Irkutsk region and the Republic of Buryatia is presented. It is shown that in a number of surveyed areas there are stable populations of this species of tick, which tend to increase in their numbers and expand their range. Conclusions. Considering these data, as well as the fact that H. concinna ticks are actively involved in the circulation of pathogens of natural focal diseases in humans and animals, we can conclude that it is necessary to systematically monitor the populations of this vector species in the Baikal region

    Species and Genetic Diversity of Representatives of the <i>Anaplasmataceae</i> Family Found in the Sympatry Zone of the <i>Ixodes, Dermacentor</i> and <i>Haemaphysalis</i> Genera Ticks

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    Introduction.On the territory of the Ekhirit-Bulagatsky district of the Irkutsk region zones of sympatry of four Ixodes ticks species are found, where the species and genetic diversity of infectious agents transmitted through tick bites may be more pronounced than in foci with a mono-dominant type of ticks’ population. In this connection, the study of the species and genetic diversity of representatives of the Anaplasmataceae family in the sympatry zone of the Ixodes ticks of closely related species was of scientific interest.Objective: To study the species and genetic diversity of members of the Anaplasmataceae family in the zones of sympatry of Ixodes ticks Ixodes persulcatus, Dermacentor silvarum, D. nuttalli and Haemaphysalis concinna, to identify the main carriers and potential reservoir hosts of ehrlichia and anaplasma.Methods. In the course of the study, 1106 specimens of adult ticks and 49 samples of small mammalian livers from the Ekhirit-Bulagatsky area were analyzed. Anaplasma and ehrlichia DNA were detected by two-round PCR in the presence of genus- and species-specific primers from the 16S rRNA gene region. The nucleotide sequences of the 16S rRNA gene and the fragment of the groESL operon were identified in some samples. Sequencing was carried out according to the Sanger method. Comparative analysis was performed using the BLASTN program and ClustalW method. Epidemiological data analysis was performed using parametric methods of statistical processing of the material.Results. The DNA of Ehrlichia muris and Anaplasma phagocytophilum were detected in all studied species of ticks in their sympatry area. However, the rate of infection of taiga ticks was significantly higher than that of H. concinna and Dermacentor spp. Potential reservoir hosts of the Anaplasmataceae family members can be classified as Microtus oeconomus, M. gregalis, Myodes rutilus and Sorex spp. When analyzing the nucleotide sequences of the 16S rRNA gene, three genetic variants of anaplasma were detected. The nucleotide sequences of the A. phagocytophilum groESL operon belonged to two genetic groups

    Mechanisms of interacting <i>Helicobacter pylori</i> with gastric mucosal epithelium. II. A reaction of gastric epithelium on <i>Helicobacter pylori</i> colonization and persistence

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    Gastric and duodenal recurrent inflammatory diseases have a high prevalence, but the role played by microbes in its development remained unclear. However, the data published in 1983 by Marshall and Warren about isolating Helicobacter pylori from the stomach mucosa of the patient with gastritis and proposing relevant cultivation methods was the turning point in investigating etiology of the upper digestive tract inflammatory disorders. Moreover, it was shown that the majority of H. pylori spp. are found within the gastric lumen upon colonization, whereas around 20% of them are attached to the epithelial cells in the stomach. In addition, effects of interacting H. pylori with gastric epithelium and activation of some defense mechanisms due to bacterial colonization and spreading were analyzed. It was found that along with triggering pro-inflammatory response induced by proteins VacA as well as phosphorylated/unphosphorylated CagA, wherein the latter is able to induce a set of protective reactions H. pylori disrupts intercellular contacts, affects epithelial cell polarity and proliferation, and activates SHP-2 phosphatase resulting in emerging diverse types of cellular responses. The activation mechanisms for the mitogen-activated protein kinase (MAPK) pathway were discussed. The ability of H. pylori to regulate apoptosis, particularly via its suppression, by expressing ERK kinase and protein MCL1 facilitating bacterial survival in the gastric mucosa as well as beneficial effects related to bacterial circulation on gastric epithelial cell survival elicited by anti-apoptotic factors were also examined. Of note, persistence of H. pylori are mainly determined by activating transcriptional factors including NF-κB, NFAT, SRF, T-cell lymphoid enhancing factor (TCF/LEF), regulating activity of MCL1 protein, in turn, being one of the main anti-apoptotic factors, as well as induced production of the migration inhibitory factor (MIF). The role of VacA cytotoxin in triggering epithelial cell apoptosis via caspase-mediated pathways was also considered. Infection with H. pylori is accompanied by release of proinflammatory cytokine cocktail detected both in vitro and in vivo. In particular, bacterial urease activating transcriptional factor NF-κB was shown to play a crucial role in inducing cytokine production. Moreover, such signaling pathways may be activated after H. pylori is attached to the cognate receptor in the gastric epithelial surface by interacting with CD74 and MHC class II molecules. Finally, a role for various CD4+ T cell subsets, particularly type 17 T helper cells (Th17) in inducing immune response against H. pylori antigens in gastric mucosa was revealed were also discussed

    Epizootic Situation on Anaplasmosis of Small Ruminants in the Irkutsk Region

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    Anaplasmosis of ruminants is a group of natural focal infections caused by bacteria from the genus Anaplasma of the Anaplasmataceae family. The main etiological agent of anaplasmosis in sheep, goats, and wild ruminants is Anaplasma ovis, which parasitizes in the erythrocytes of these animals. The purpose of this study was the finding and identification of Anaplasma spp. in the blood of small ruminants using genetic methods and obtaining data on the distribution of anaplasmosis in the Irkutsk region. 20 goat blood samples, 611 sheep blood samples and 209 Dermacentor nuttalli ticks from 12 districts of the Irkutsk region were examined for the presence of Anaplasma spp. Only one type of anaplasma, A. ovis, was found among the genotyped samples. A. ovis was found in the blood of sheep and goats in all of the studied districts of the Irkutsk region. The proportion of sheep blood samples containing anaplasma DNA varied from 30 % to 85 %, in goats – from 10 % to 100 % in different districts, and averaged 57.8 % in sheep and 55,0 % in goats. Frequency of infection of D. nuttalli ticks with A. ovis was 5.7 %. The nucleotide sequences of the samples detected in the blood of small ruminants on the territory of the Irkutsk region differed from each other by a single nucleotide substitution and were identical to the sequences of the type strain Haibei, as well as the sequences of A. ovis previously found in the blood of sheep from Mongolia, deer from China, and Dermacentor niveus and Dermacentor nuttalli ticks from China. These sequences were also identical to the sequences previously found in the blood of sheep from Altai and in Dermacentor nuttalli ticks from Tuva, which indicates the wide distribution of these A. ovis genovariants in Siberia and the probable role of D. nuttalli as a carrier of the agent of anaplasmosis of small ruminants in the Irkutsk region

    Противокоронавирусные свойства брассиностероидов

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    Antiviral properties of natural brassinosteroids of the campestane, ergostane, and stigmastane series (6-ketones and B-lactones) and their (22S,23S)-analogs were studied using the seasonal human respiratory alpha-coronavirus 229E (HCoV-229E) as an example. The presence of anticoronavirus properties was shown for a number of studied compounds. In general, 6-ketones were more active than B-lactones. The maximum inhibitory effect (EC50 21.1 µM) in relation to the reproduction of HCoV-229E was noted for (22S,23S)-epicastasterone.На примере сезонного респираторного альфа-коронавируса человека 229Е (HCoV-229E) проведено изучение противовирусных свойств природных брассиностероидов кампестанового, эргостанового и стигмастанового рядов (6-кетонов и B-лактонов) и их соответствующих (22S,23S)-аналогов. Показано наличие противокоронавирусных свойств для ряда изученных соединений. 6-Кетоны в целом оказались более активными в сравнении с B-лактонами. Максимальный показатель ингибирующего действия (EC50 21,1 µM) в отношении репродукции HCoV-229E отмечен для (22S,23S)-эпикастастерона

    CHARACTERISTICS OF THE BAIKAL SUBTYPE OF TICK-BORNE ENCEPHALITIS VIRUS CIRCULATING IN EASTERN SIBERIA

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    Background. During the study of the genetic variability of the tick-borne encephalitis virus (TBEV) in Eastern Siberia, a group of 22  strains with a unique genetic structure significantly different from all  known TBEV subtypes was identified. This TBEV variant was  tentatively called “group 886”. Therefore, for this original TBEV  variant it was necessary to study the genetic, biological properties of the “group 886” strains, clarify its TBEV taxonomic status, its range, evolutionary history, etc.Aim. The generalization of the currently available data on genetic and biological properties of TBEV “886” group.Materials and methods. The genetic structure of “group 886” strains was studied by the complex of molecular-genetic methods (MHNA, sequencing of fragments or the complete genome).Results. It was shown that “group 886” strains form a separate cluster on phylogenetic tree, and the level of genetic differences  from other genotypes is more than 12 %. It was defined that this  TBEV variant has its own area (Irkutsk region, Republic of Buryatia,  Trans-Baikal region, Northern Mongolia). Its ecological connection  with all links of the transmissive chain (ixodid ticks, small mammals,  human), participation in human pathology, stability and duration of  circulation in the Baikal region, individual evolutionary history  were proved. Some phenotypic characteristics of the “group 886” strains were considered.Conclusion. The presented data testify to the validity of the “886 group” isolation as an independent genetic type. Taking into account  the geographical distribution of this TBEV genotype, we propose to assign it the name “Baikal genotype/subtype”

    Characteristics of genetic and phenotypic properties of tick-borne encephalitis virus strains isolated from various source on the territory of Eastern Siberia

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    Since ixodid ticks and their feeders (vertebrates) form the basis of the tick-borne encephalitis virus (TBEV) population, it was interesting to obtain a genetic characteristic of strains isolated from various sources in the territory of Eastern Siberia. In our study, it was found that the circulation of TBEV of genotypes 1, 2, 3, 5 and "polytypic" strains in the territory of Eastern Siberia is maintained both by the main vectors (I. persulcatus ticks) and by their feeders (small and large mammals, birds). The distribution of genotypes in strains groups from ixodid ticks and vertebrates varied. TBEV strains of genotypes 1 and 2 were significantly more often isolated from rodents, and genotype 3 from ixodid ticks (p < 0.05). Isolates of genotype 3 (85.5 %) prevailed in the group of strains isolated from ixodid ticks, of which 29.6 % belonged to "Vasilchenko", and 25.6 % to "Zausaev"subgenotypes. Genotypes 1 and 2 were represented by single isolates (3.3 % and 1.3 %, respectively). Among strains isolated from warm-blooded hosts, the proportion of genotype 1 was 35.3 %, genotype 2 -11.8 %, genotype 3 - 35.3 %. More than half of genotype 3 strains (58.3 %) were related to "Vasilchenko" subgenotype, and the strains of "Zausaev" subgenotype were not detected. The obtained data suggest that ixodid ticks and warm-blooded animals are amplifiers of TBEV of genotypes 3 and 1, respectively. The certain differences in the phenotypic characteristics of strains isolated from ticks and warm-blooded animals have been revealed. It has been found that strains isolated from ticks are more homogeneous in their antigenic characteristics, less heterogeneous in S-feature than strains isolated from warm-blooded sources. The strains isolated from warm-blooded animals demonstrate somewhat greater resistance to warming but reducing the reproduction of the virus at 42 °C, and have greater virulence compared to strains isolated from ticks

    The distribution of tick-borne encephalitis virus genotypes in different types of landscapes of Eastern Siberia

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    To find out what is the role of some environmental factors in the formation of a heterogeneous viral population, the analysis of the distribution of tick-borne encephalitis virus (TBEV) genotypes in different types of landscapes of Eastern Siberia has been carried out. In our study, it was shown that TBEV area in all investigated landscapes of Eastern Siberia is represented not only by TBEV of genotype 3, absolute dominance of which is noted in the studied regions, regardless the landscapes where the foci are located, but also by strains of other genotypes. The relationship between genotypes 1,3 and "polytypic" strains with a certain type of landscape and the degree of their development by man has not been established. The prevailing number of strains of TBEV genotype 5 is isolated from the material collected in the Transbaikalia, in the landscapes of the mountain taiga. They, as well as the strain of genotype 4, are found in the foci, where joint circulation of several TBEV genotypes is noted. The strains of TBEV genotype 2 were revealed in the landscapes of plains and plateaus taiga and insular steppes and forest steppes of the southern part of the Baikal region. Moreover, the detection of RNA of TBEV genotype 2 in the "polytipic" 763-87 and 765-87 strains isolated in the floodplain and forest-steppe landscapes of the Barguzin hollow does not exclude the possibility of circulation of TBEV genotype 2 in the Transbaikalian foci. The greatest genetic heterogeneity of TBEV is observed in natural foci located along Lake Baikal and in the southeastern part of Transbaikalia

    Calcium effect on collagen metabolism in the spongy bone tissue in alloxan-induced rats

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    In order to determine the effect of exogenous calcium on bone collagen metabolism alloxan-induced rats parenterally administered calcium gluconate. During the experimental work carried out comparative analysis of the metabolism of collagen type I in experimental animals when administered calcium and rats with alloxan diabetes. In the group studied rodents installed intensification type I collagen metabolism in the spongy bone with a predominance of anabolic processes as compared to animals with experimental diabetes.С целью выяснения влияния на обмен костного коллагена экзогенного кальция крысам с аллоксановым диабетом парентерально вводили глюконат кальция. В ходе экспериментальной работы проведен сравнительный анализ показателей метаболизма коллагена I типа у подопытных животных при введении кальция и крыс с аллоксановым диабетом. В группе исследуемых грызунов установлена интенсификация процессов метаболизма коллагена I типа в губчатой костной ткани с преобладанием анаболических процессов по сравнению с животными с экспериментальным диабетом

    ГЕНЕТИЧЕСКОЕ РАЗНООБРАЗИЕ ПЕНИЦИЛЛИНУСТОЙЧИВЫХ STREPTOCOCCUS PNEUMONIAE

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    Fifty five Streptococcus pneumoniae isolates with reduced susceptibility to penicillin, obtained from patients with respiratory tract infections during 2003 –2007, were analyzed by MLST. Ten isolates were identified by MLST as Streptococcus «viridians» group. Among the remaining isolates 33,3% (n=15) belonged to global clonal complex CC81 and demonstrated reduced susceptibility to macrolides, tetracyclynes and chloramphenicol, three isolates were additionally resistant to levofloxacin. Clonal complex CC271 was represented by 5 isolated (11,1%), CC315 – by 4 (8,9%), CC315 – by 3 (6,7%), CC156, CC280 and CC1012 were represented by 2 (4,4%) isolates each. Isolates of clonal complexes 271 and 315 demonstrated high level of associated resistance to macrolides. Twelve clonal complexes were represented by single isolates. More than 50% of isolates with reduced susceptibility to penicillin belonged to three global clonal complexes. Probably these clonal complexes were imported to Russia from other geographical regions.Методом мультилокусного сиквенстипирования (MLST) были изучены 55 штаммов Streptococcus pneumoniae со сниженной чувствительностью к пенициллину, полученных от пациентов с инфекциями дыхательных путей в 2003–2007 гг., в различных регионах России. Десять штаммов были идентифицированы методом MLST как Streptococcus «viridians» group. Среди оставшихся 45 штаммов 33,3% (n=15) относились к глобально распространенному клональному комплексу 81 (CC81) и проявляли ассоциированную устойчивость к макролидам, тетрациклину, а также хлорамфениколу, три штамма были дополнительно устойчивы к левофлоксацину. К клональному комплексу 271 относились 5 (11,1%) штаммов, к 315 – 4 (8,9%), к 414 – 3 (6,7%), к клональным комплексам 156, 280, 1012 – по 2 (4,4%). штаммы клональных комплексов 271 и 315 характеризовались высокой частотой ассоциированной устойчивости к макролидам. Двенадцать клональных комплексов были представлены единственными изолятами. Таким образом, более 50% пневмококков, проявляющих сниженную чувствительность к пенициллину, относились к трем глобально распространенным клональным комплексам. Наиболее вероятным представляется импорт этих клонов из других регионов мира и их распространениена территории России
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