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

SPECIES AND GENETIC VARIETY OF TICK INFECTIONS PATHOGENS ON THE TERRITORY OF THE EASTERN SIBERIA

The article sums up long-term, researches of studying of species and genetic variety of tick infections pathogens in combined, natural focuses of the Eastern Siberia. The results of the research testify to the high genetic variety of regional population, of tick-borne encephalitis virus that is represented, by the strains of Far-Eastern, West, Ural-Siberian genotypes, the strains of the group 886 and. 178-79. Infection of Ixodidae by the next pathogens: B. garinii, B. afzelii, R. sibirica, R. raoultii (генотипы. R. sp. DnS14, R. sp. DnS28), E. muris, A. phagocytophilum и Candidatus «Neoehrlichia mikurensis» was determined

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”