RESULTS OF RECONNAISSANCE STUDIES ON DETECTION OF BABESIOSIS FOCI IN THE IRKUTSK REGION

This article contains results of reconnaissance studies intended to find foci of babesia in the Irkutsk region. Babesia DNA were founded in two types of ticks (I. persulcatus, H. concinna) in the three districts of the Irkutsk region (Ekhirit-Bulagatsky, Irkutsky, Shelekhovsky). The analysis of 1220 nr length nucleotide sequences of 18S rRNA gene of five Babesia samples was conducted. It was shown that the identified Babesia sequenced differ from previously known, and refer to the two genetic groups. The first group included babesia, genetically most similar to the sheep pathogen Babesia crassa, second contains sample, nucleotide sequence of which is significantly different from all known (less than 95 % homology)

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

IDENTIFICATION OF THEILERIA EQUI IN HORSE BLOOD IN THE IRKUTSK REGION

This paper describes the detection of Piroplasmida DNA in the blood of horses. 166 blood samples of horses from five districts of the Irkutsk region were studied. The high piroplasms infection rate in horses (69 %) was found. For six positive samples nucleotide sequences were determined. The comparison of determined 18S rRNA gene sequences with previously published sequences showed that all revealed piroplasms DNA samples are Theileria equi. The data are presented on the lethal cases of equine piroplasmosis in the Irkutsk region in 2008

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

Detection of Babesia and Anaplasmataceae bacteria in small mammals from Irkutsk and Novosibirsk regions

Tissue samples from 228 small mammals captured from 2013 to 2015 in four districts of Irkutsk region and in one district of Novosibirsk region were examined for the presence of Anaplasmataceae bacteria and Babesia parasites by nested PCR method with subsequent sequencing of positive samples. In Ekhirit-Bulagatskiy District of Irkutsk region, Babesia microti DNA was found in 10.9 % of small mammals, Anaplasma phagocytophilum DNA - in 7.3 %, and Ehrlichia muris DNA - in 1.8 %. Infected mammals were not found in the other three examined districts of Irkutsk region. In Novosibirsk region, B. microti DNA was found in 8.9 % of small rodents, A. phagocytophilum DNA - in 8.9 % of small mammals, and Candidatus Neoehrlichia mikurensis DNA - in 8.9 % of small mammals. The identified infection agents corresponded to microorganism species and genetic variants previously found in Ixodes persulcatus ticks but not in ticks of other species

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

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

Identification of the etiological agent of equine piroplasmosis in Western and Eastern Siberia

Equine piroplasmosis is a natural tick-borne infection caused by hemoprotozoan parasites of the order Piroplasmida, Babesia caballi and Theileria equi. Animals that recover from piroplasmosis remain persistently infected carriers and can transmit pathogens to vector ticks. Cases of equine piroplasmosis are periodically observed in Siberia, however, no agent of equine piroplasmosis has yet been genetically characterized in Russia. The aim of this work was studying the prevalence of the infectious agents of piroplasmosis in horses from Siberia and genotyping the detected agents. Blood samples from 155 horses were examined for the presence of Babesia and Theileria DNA by nested PCR with the subsequent sequencing of positive samples. DNA of T. equi was found in blood samples from 57.9 %, 38.5 % and 65.0 % of horses from Novosibirsk province, Irkutsk province, and the Republic of Altai, respectively. T. equi DNA was found in the samples from almost all sampling sites included in this study, indicating that most of the studied sites are endemic for equine theileriosis. Surprisingly, DNA of B. caballi was not found in any of the samples examined, even though this agent had previously been detected in many regions in Russia, including Altai. The analysis of the determined 18S rRNA gene sequences demonstrated that T. equi samples belonged to two genetic groups, which differed significantly by the sequences of the variable (V4) region of the gene. All T. equi sequences from group B were identical and corresponded to T. equi sequences found in the blood of horses from China and Korea, while T. equi sequences from group A differed by 1–5 nucleotide substitutions and were identical to the sequences from the blood of horses from India and Brazil or differed from them by single mismatches. Notably, in this study the presence of etiological agent of piroplasmosis in blood samples from horses in Russia was genetically confirmed for the first time

Epizootic Situation on Anaplasmosis of Small Ruminants in the Irkutsk Region

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

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