IDENTIFICATION OF HUMAN GRANULOCYTIC ANAPLASMOSIS AND MONOCYTIC EHRLICHIOSIS NATURAL FOCI IN THE KRASNOYARSK TERRITORY

Microbiological monitoring of the six districts of the Krasnoyarsk Territory was conducted in order to prove the existence of natural foci of human granulocytic anaplasmosis (HGA) and monocytic ehrlichiosis (HME) on its territory. Two-round PCR method was used for the detection of Anaplasma and Ehrlichia DNA. 374 samples from mites were analyzed with two-round PCR for the presence of Anaplasma and Ehrlichia DNA: 341 specimens of Ixodes persulcatus and 33 specimens of Haemaphysalis concinna. Ticks were collected from vegetation on the flag in the 6 districts of the Krasnoyarsk Territory: Yeniseisky, Achynsky, Sharypovsky, Ilansky, Minusinsky and Ermakovsky, belonging to different climate zones and have landscaped, geo-botanical and faunal features. The study showed that 5.6 % of taiga ticks infected with E. muris, 2,1 % with A. phagocytophilum. In 0.3 % of carriers we identified mixtinfected E. muris and A. phagocytophilum. These data indicate presence of HGA and HME foci in the central, western and southern parts of the Krasnoyarsk Territory

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

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

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

RESULTS OF GENOTYPING OF STRAINS AND RNA ISOLATES OF TICK-BORNE ENCEPHALITIS VIRUS ISOLATED FROM SICK PEOPLE IN IRKUTSK REGION AND BURYAT REPUBLIC

Genotyping of nine strains and nine isolates of tick-borne encephalitis virus RNA (TBE) isolated from patients in the Irkutsk Region and. the Buryat Republic in 1963-2009 years conducted. The investigations revealed that three TBE virus genotypes are involved in the etiology of the TBE: Ural-Siberian (genotype 3), Far Eastern (genotype 1) and. European (genotype 2). It is found that the TBE virus of Far East and. Ural-Siberian genotypes can cause disease with a wide spectrum of clinical manifestations: acute TBE (focal and. nonlocal forms), chronic TBE (encephalitic form, progressive course.) Prospects of application of molecular genetic techniques for the rapid indication and. identification of the TBE virus in the blood of sick people are shown

MODERN EPIDEMIOLOGY OF VECTOR-BORNE TICK-BORNE INFECTIONS IN NORTHERN DISTRICTS OF THE IRKUTSK REGION

Проведен вирусолого-микробиологический мониторинг семи северных районов Иркутской области. Полученные в ходе исследования данные свидетельствуют об изменении эпидемиологической ситуации в отношении клещевых инфекций на территории данных районов. Отмечается продвижение природных очагов на север. На территории северных районов выявлены сочетанные очаги, клещевых инфекций, в том числе обнаружена циркуляция новых для Восточной Сибири патогенов - E. muris, A. phagocytophilum, B. miyamotoi

MOLECULAR GENETIC ANALYSIS OF INFECTION AGENTS OF FARM ANIMALS ANAPLASMOSIS ON THE TERRITORY OF WESTERN AND EASTERN SIBERIA

A total of 452 blood samples of cattle, sheep and goat collected in different regions of Altai Republic, Altai region, Novosibirsk and Irkutsk regions were examined on the presence of Anaplasma DNA using nested PCR with subsequent sequencing of PCR fragments. Anaplasma DNA was found in all examined blood samples of goat, 75.2 % samples of sheep, and 49.3 % samples of cattle. A molecular genetic analysis has demonstrated that intraerythrocytic Anaplasma ovis circulates in goat and sheep blood, while an intraerythrocytic Anaplasma sp. Omsk and a new intraerythrocytic Anaplasma sp. Sibl22, which cannot be attributed to any known species, circulate in cattle blood. In addition to intraerythrocytic Anaplasma, DNA of monocytic Anaplasma bovis was found in one blood sample of cattle

IZOENZYME STRUCTURE OF POPULATIONS OF TICKS IXODES PERSULCATUS SCHULZE (ACARI: IXODIDAE) IN RECREATION AREAS OF IRKUTSK CITY

Allozyme structure of the population of ticks Ixodes persulcatus in 8 enzyme systems is shown in two samples of ticks from the recreational areas in suburbs of Irkutsk. From the total of 13 loci, which encode these enzymes, eight were polymorphic. Based on allozyme analysis of populations of mites, it is found that most of them show intrapopulation heterogeneity and. the lack of difference between the two populations from different foci. A similar pattern may indicate a large rate of migration of genes between populations and. their close relatives

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

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

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

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

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

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”