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The aim of the work was to determine the species diversity of the causative agents of Ixodidae tick-borne borrelioses in Ixodes persulcatus ticks in the Khabarovsk Territory.Materials and methods. During the epidemic season (April–October) 2017–2023, 4751 specimens of I. persulcatus Schulze, 1930, removed after attachment to humans and 418 ones collected from vegetation in the Khabarovsk Region, were studied. Ixodidae ticks were collected in the green areas of Khabarovsk city during the snowless season of 2021–2023, as well as in the territory of the Khabarovsk Region on the flag. DNA of the borrelia complex Borrelia burgdorferi sensu lato (s.l.) and B. miyamotoi was detected in ticks using real-time polymerase chain reaction (PCR). Differentiation of borrelia species in samples containing genetic material of B. burgdorferi s.l. was carried out in two stages. At the first stage, the presence of DNA from borrelia of the B. garinii s.l. group (B. garinii + B. bavariensis) and B. afzelii DNA was determined in the sample. At the second stage, positive samples of B. garinii s.l. were differentiated into B. garinii sensu stricto (s.s.) and B. bavariensis. Results and discussion. In engorged ticks, genetic material of B. burgdorferi s.l. was detected in 45.7 % of the cases, DNA of B. miyamotoi was identified in 7.2 % of samples. In ticks collected from vegetation, the DNA of B. burgdorferi s.l. was detected in 38.0 % of cases. Upon further study, the genetic material of B. afzelii and borrelia of the B. garinii s.l. group was identified in 47.2 % of cases for both pathogens. Within the group B. garinii s.l., DNA of B. bavariensis was detected in 18.6 %, B. garinii s.s. – in 8 % of samples, at the same time, mixed infection was noted in 53.3 % of cases. The infection rate with B. afzelii in I. persulcatus ticks turned out to be statistically significantly higher than that for B. garinii s.s. and B. bavariensis, thereat statistically significant differences in tick infection rates with B. garinii s.s. and B. bavariensis was not detected.

Background. Infections transmitted to humans by the bites of ixodid ticks remain an urgent public health problem. In this work we explored the natural foci of tickborne infections located in the valley of the Chikoy River, which is a part of the buffer zone of the Baikal natural territory.The aim. To characterize the modern diversity and prevalence of tick-borne pathogens in the ecosystems of the valley of the Chikoy River (Trans-Baikal Territory, Russian Federation).Materials and methods. Thirteen sampling sites were located in typical biotopes throughout the Chikoy valley. In total 48 adult Ixodes persulcatus ticks, 1 female Haemaphysalis concinna tick and 38 specimens of small mammals were studied. All samples were tested for infection with seven tick-borne pathogens using multiplex real-time PCR.Results. No pathogens were detected in the H. concinna specimen. No R. sibirica and R. heilongjiangensis were detected both in ticks and in rodents. Among I. persulcatus, tick-borne encephalitis virus (TBEV), and the prevalence of Borrelia burgdorferi s. l. comprised 39.5 %, A. phagocytophilum – 16.7 %, B. miyamotoi – 8.3 % and Ehrlichia sp. – 2.1 %. Among infected ticks 6.2 % were co-infected with B. burgdorferi s. l. and A. phagocytophilum. Four rodent hosts of ticks and infections were identified: Myodes rufocanus (44.7 %), Apodemus peninsulae (39 %), Microtus oeconomus (13.2 %) and M. rutilus (2.6 %). Mean prevalence of B. burgdorferi s. l. in rodents comprised 39.5 %, B. miyamotoi – 28.9 %, Ehrlichia sp. – 21.1 % and A. phagocytophilum – 18.4 %. TBEV was detected in 5.3 % of rodents.Conclusion. At least five tick-borne pathogens circulate in the Chikoi River valley, i. e. TBEV, B. burgdorferi sensu lato, A. phagocytophilum, B. miyamotoi and Ehrlichia sp. The wide spread of I. persulcatus and abundance of competent rodent hosts of infections and ticks indicates that natural foci of tick-borne diseases are widely distributed in the Chikoi River valley.

Background. To date, the genetic variability of Rickettsia helvetica has not been sufficiently studied.The aim. To study the prevalence and genetic variability of R. helvetica in Ixodes spp. collected in Western Siberia and the Russian Far East.Materials and methods. Ixodes spp. collected from rodents in the Omsk province, Western Siberia (n = 280) and collected by flagging on Putyatin and Russky Islands in Primorsky Krai, Russian Far East (n = 482) were analyzed for the presence of Rickettsia spp. All positive samples were genotyped for the gltA gene fragment. For a number of R. helvetica samples, fragments of the 16S rRNA, ompA, ompB, sca4, htrA, and groEL genes and 23S–5S intergenic spacer were additionally sequenced.Results. Four Rickettsia species (R. helvetica, “Candidatus Rickettsia tarasevichiae”, “Candidatus Rickettsia uralica”, and “Candidatus Rickettsia mendelii”) were found. Of them, R. helvetica was identified in 72.2 % of Ixodes apronophorus and 18.8 % of Ixodes trianguliceps from the Omsk province and in single Ixodes persulcatus from the Omsk province and Putyatin Island. This is the first finding of Rickettsia spp. in I. apronophorus. All known R. helvetica sequences from this study and the GenBank database belonged to four well supported monopheletic groups forming genetic lineages I–IV. Lineage I included European isolates from Ixodes ricinus, Western Siberian isolates from I. persulcatus, and some sequences from I. apronophorus. All R. helvetica sequences from I. trianguliceps from the Omsk province and I. persulcatus from the Komi Republic and one sequence from I. apronophorus were assigned to lineage II. Most sequences from I. apronophorus formed lineage III; all known R. helvetica sequences from I. persulcatus from the Far East formed genetic lineage IV.Conclusion. The genetic heterogeneity of R. helvetica population was first demonstrated. Known isolates of R. helvetica are reliably assigned to four genetic lineages, but not in all cases the association of different lineages with a specific tick species or specific territory was observed.

Extensive spread of tick-borne diseases poses a significant problem for public health and the health of the population living in endemic areas.The aim of the study was to search, analyze genetic material and identify new viral agents of the Phenuiviridae family in taiga ticks collected in Asian regions of Russia using the method of high throughput sequencing.Materials and methods. The study involved 1460 taiga ticks collected in suburban areas of the Tomsk, Yekaterinburg and Primorsky Territory. The genetic material isolated from ticks was sequenced using Illumina technology followed by phylogenetic analysis.Results and discussion. Analysis of the sequencing results made it possible to detect extended nucleotide sequences of the L-gene fragment characteristic of the Phenuiviridae family viruses. We were able to identify 20 nucleotide sequences the length of 250 bp on average in homogenates of Ixodes persulcatus ticks. Eighteen isolates have been identified as members of the genus Uukuvirus and two isolates have been assigned to the genus Phlebovirus, Phenuiviridae family. Phylogenetic analysis has shown that all isolates of the genus Uukuvirus fall under the cluster of Tacheng tick virus 2 belonging to the species Tacheng uukuvirus. They form a separate phylogenetic group which is closely related to two Romanian variants of 2019. Tacheng tick virus 2 was detected in all three surveyed regions of the Asian part of Russia. Two Tomsk isolates of phlebovirus were classified as Sara tick phlebovirus and they clustered with two isolates of phleboviruses from Karelia. Thus, the genetic material of Tacheng tick virus 2 and Sara tick phlebovirus belonging to two genera of the family Phenuiviridae was found in I. persulcatus ticks collected in three geographically different regions of the Asian part of Russia.

The purpose of the research is to identify ixodid ticks and their pathogens in the left bank area of Central Yakutia. Materials and methods. The work was carried out in 2019–2020 in the left bank area of Central Yakutia. Nine ticks were collected in 2019, and 27 ticks in 2020. We studied forest shrub stations, steppe stations, meadow field stations, near-water stations and stations of settlements. To determine faunal and ecological characteristics of ectoparasites in the territory, we used standard collection methods. The tick species was determined using morphological keys by N. A. Filippova; the determination correctness was confirmed by the PCR method. The collected ticks were studied for causative agents of babesiosis and tick-borne viral encephalitis using PCR analysis. Results and discussion. One species of ixodid ticks, Ixodes persulcatus, inhabits the left bank area of Central Yakutia. Haemaphysalis concinna was not found in Yakutia. In 2008, a natural focus of blood protozoan disease of domestic reindeer appeared for the first time in Yakutia in its central zone. Recently, an increase in the number of I. persulcatus has been observed. Tick activity is recorded from the second decade of May to the second decade of August. The ground-squirrel Spermophilus parryii is the main host for the preimaginal stages. Pathogens were not detected when ticks were examined for causative agents of babesiosis and tick-borne viral encephalitis using PCR analysisd.

Over the last years, an increasing rate of ixodes tick bites has been registered in the northern regions of the European Russia. In addition, the number of subjects request medical assistance due to tick bites has been dramatically increased in the Komi Republic. In addition, incidence of tick-borne encephalitis was also increased particularly starting since 2009. However, highly limited data on pathogen genetic diversity related to viral tick-borne infections in this region are currently available. Taiga ticks (Ixodespersulcatus) collected from the Komi Republic southern and central part vegetation were examined to identify and genotype tick-borne viruses. Individual ticks were used to identify by RT-PCR viral RNA coupled to tick-borne encephalitis and Kemerovo viruses. Viral genome fragment sequencing allowed to unambiguously identify these viruses. It was found that viral RNA tick-borne encephalitis was detected in 6.8±1.2% individual ticks. Moreover, tick-linked isolate genotyping based on analyzing E protein gene fragment nucleotide sequence derived from tick-borne encephalitis discovered that 35% and 65% isolates belonged to the Far Eastern and Siberian subtype, respectively. In addition, subsequent phylogenetic analysis demonstrated that at least four variants of the Siberian and Far Eastern subtypes of tick-borne encephalitis virus were detected, which were close to the viruses circulating in the Urals and Siberia. In contrast, prevalence of Kemerovo virus in taiga ticks was 0.8±0.2%. Sequencing of Kemerovo virus RNA-dependent RNA polymerase gene fragment showed around 94% homology with the remainder of the Kemerovo virus strains. Phylogenetic analysis of the Kemerovo virus genome fragments demonstrated at least two subtypes circulating in the Komi Republic. Thus, it was suggested that tick-borne encephalitis virus was introduced relatively recently from the Urals and Siberian region into the natural foci of the Komi Republic. Moreover, genetic differences found in Kemerovo virus strains presume for them a longer lasting evolution throughout the natural foci of this region. In addition, a potential role for birds and their ticks in rapid spreading of viral tick-borne infections in the Komi Republic is also discussed. Thus, the data on genetic diversity of the viral agents related to tick-born encephalitis and Kemerovo fever may be useful for improving their diagnostics, prevention and treatment in the Komi Republic.

The sharp rising incidence of tick-borne encephalitis (TBE) in Komi Republic at the North-east of European Russia was recorded last decades. Tick-bite incidence also was grown. Rapid rise of TBE incidence growth and Ixodidae ticks depends on a number of factors, and the impact of climate change being one of them. Ixodes persulcatus ticks is considered as a main vector of TBE in Komi. Our objective is to estimate the influence of air temperature change on the tickbite incidence and Ixodes persulcatus population in Komi. Komi Republic is located near the Polar circle where the northern frontier of Ixodes persulcatus ticks situated and we expected the growth of tick’s population. The number of Komi inhabitants seeking medical care after tick bites in 1992–2014 was considered. Gridded monthly air temperature data with grid size 0.5 degree were recalculated to temperature referred to Komi administrative units. The time series of annual number of tick victims from 1992 till 2014 and model air temperature from 1948 till 2016 for all Komi administrative units were compiled. We analyzed the data on tick-bite incidence in Komi administrative units in relation to changes in local annual average air temperature within the study area. The linear dependence of the tick-bite incidence on air temperature was established when of the tick-bite incidence is represented in logarithm form. The tick population depends not only on temperature but humidity, landcover and hosts. Described areas of Komi belong to humid climate, where precipitations exceed evaporation. Most of the Komi territory is covered by taiga with underwood, grass and bush. Hosts of the first and the major levels are represented by birds and rodents. The dependence of tick-bite incidence and temperature looks like “Malthus’s law”, but the development of population depends on temperature not on time. The exponential growth in the nearest future will ceased and the population will proceed to stable phase. Ticks population in Komi Republic is moving to the North and the air temperature determines the dynamics of population.

Objective of research: To study the spread of causative agents of babesiosis in ticks collected on the territory of the Kirov region with the use of molecular-genetic methods. Materials and methods: In this paper, the method of molecular-genetic detection of genetic material of the pathogen in the sample was used (the method of polymerase chain reaction (PCR). Ticks were collected from vegetation cover as well as from people and domestic animals (dogs, cats). Ticks were estimated according to identification tables. Causative agents of babesiosis were determined by the extraction of total nucleic acids from each tick; all ticks were examined using PCR. Total DNA extraction from ticks stored in 70% ethyl alcohol was performed with the use of guanidine thiocyanate. The proportion of ticks infected with Babesia was determined depending on the year, collection area on the territory of the Kirov region, species and sexual belonging of ticks. Results and discussion: It was found that the major tick vectors of Babesia on the territory of the Kirov region are ticks Ixodes persulcatus . In addition, two other tick species Dermacentor reticulatus and I. ricinus were detected in that region. It was shown, that the rate of Babesia infection in ticks Ixodes persulcatus was higher than in D. reticulatus and I. ricinus . The average percentage of ticks infected with Babesia was 53,07 %. A gradual increase of percentage of infected individuals with the maximum value 73,2 % was registered in 2012. However, in the following year, a significant decrease (51,7 %) was reported, and the minimum number of ticks infected with Babesia was observed in 2014 (37,4 %). A significant increase in infestation of ticks was newly observed in 2015 (50,4 %). It was found that male and female ticks are equally likely to be vectors for Babesia. Infection rates in male and female ticks were 54,5 and 49,3 %, respectively. Fluctuations in the number of infected ticks depending on the year (maximum in 2012 and minimum in 2014) were determined. Ticks from South-West districts of the region are mostly infected with Babesia. In the city of Kirov, 55,8 % of ticks are infected with Babesia in spite of acaricide treatment.

Introduction. The detection of the first cases of tick-borne human granulocytic anaplasmosis in Russia, discovery of genetic markers for Anaplasma spp. in ixodid ticks and reporting of a significant number of cases of tick-borne infections in the southern part of Western Siberia give reason to suppose that causative agents of tick-borne anaplasmosis may be transmitted in Tomsk and its suburbs. Objective. To study the distribution and species biodiversity of A. phagocytophilum in ixodid ticks in Tomsk Region. Materials and methods. The analysis of 690 individual ixodid ticks (larvae and adults) was carried out for Ixodes persulcatus (n = 530) and Dermacentor reticulatus (n = 160) ticks collected in 2015–2016 on the territory of urban and suburban biotopes of Tomsk. Primary screening of ticks for the presence of genetic material of A. phagocytophilum was conducted using two-round PCR with species-specific primers for the 16S rRNA gene. The amplification (1,220 kB) of the groESL fragment of the heat shock protein operon was performed for positive isolates with subsequent determination of the nucleotide sequence in the gene fragment for phylogenetic analysis. Results. The number of A. phagocytophilum positive samples for I. persulcatus (larvae) was 1.2 ± 0.6%, I. persulcatus (adult) was 1.8 ± 0.7%; and D. reticulatus (adult) was 0.6 ± 0.3%. Analysis of the nucleotide sequence of the gene fragments in groESL operon for nine isolates confirmed that the genetic material of the granulocytic anaplasmosis was detected. Phylogenetic analysis showed that all the isolates belonged to the first group of the “new cluster” of A. phagocytophilum. Conclusion. The causative agent of human granulocytic anaplasmosis has been newly detected in I. persulcatus ticks collected in urban and suburban biotopes of Tomsk and in D. reticulatus from urban foci.

Kemerovo virus (KEMV), a member of Reoviridae family, Orbivirus genus, is transmitted by ixodes ticks and can cause the damage of human central nervous system. The occurrence and genetic diversity of KEMV in Western Siberia still remained poorly studied, so, the aim of this work was to investigate the prevalence and genetic variability of KEMV in ixodid ticks from Western Siberia. A total of 1958 Ixodes persulcatus, I. pavlovskyi ticks and their hybrids from Novosibirsk and Omsk provinces, Altai Republic (Russia) and East Kazakhstan province (Kazakhstan) were analyzed for the presence of KEMV and tick-borne encephalitis virus (TBEV) RNA. It was shown that KEMV distribution area in Western Siberia was wider and included Northern and Northeastern Altai in addition to Omsk and Novosibirsk provinces. For the first time this virus was found in Kazakhstan. The occurrence of KEMV was statistically lower than TBEV in most locations in Western Siberia. KEMV was found both in I. persulcatus and I. pavlovskyi ticks and in their hybrids. Notably, KEMV variants found in 2010s genetically differ from those isolated in 1960s. Moreover, the possibility of reassortment for KEMV was demonstrated for the first time.

Blood samples were taken from 541 small mammal captured in 2013-2015 in Znamensky district of Omsk region from Ixodes persulcatus and Ixodes trianguliceps sympatric area and examined for the Babesia spp. presence by nested PCR with subsequent sequencing of positive samples. Babesia microti DNA was found in 31,1 % of positive samples; a proportion of infected mammals varied from 5,3 % to 61,6 % in different sampling periods. B. microti DNA was found in samples from three prevailing Myodes species as well as from a root vole (Microtus oeconomus), field voles (Microtus argestis) and Siberian chipmunks (Tamias sibiricus). It was shown that identified B. microti samples belong to two genetic groups: B. microti 'US'-type and B. microti 'Munich'-type; notably that > 90 % infected mammals contained DNA of nonpathogenic for human B. microti 'Munich'-type. We suppose that I. trianguliceps tick is the most probable vector of B. microti 'Munich'-type.

The aim was to study the species composition, abundances and distribution of ixodid ticks in the City of Petrozavodsk. Samples were collected in May–September, 2006–2014 using two methods simultaneously: by flagging from vegetation and by collection from dogs. In addition, 47 tick specimens were provided by veterinary clinics based in Petrozavodsk. Records from the entire study period include three tick species: Dermacentor marginatus, Ixodes persulcatus and Ixodes ricinus. A substantial share in the samples belonged to Ixodes persulcatus – 344 specimens. I. ricinus (5 females) was identified only in the material coming from veterinary clinics. The only female D. marginatus was obtained from a dog from a route through the central part of the city. Samples collected by flagging contained only I. persulcatus, its relative abundance along the control transect (Botanical Garden, suburbs) ranging within 0.9–22 specimens per flag-km. I. persulcatus abundance within city limits was low (

Among main factors that influence intensity of tick-borne encephalitis foci one can distinguish the numbers of core vector (here, taiga tick Ixodes persulcatus) and the percentage of infected ticks. This paper shows the results of five-year monitoring of the tick-borne encephalitis focus, which is situated near Irkutsk city. Detected are the variations in numbers and infestation of the core vector of tick-borne encephalitis, both spatial and temporal. Cause-effect connection between these factors and human TBE morbidity is not found. However, morbidity rates of the Irkutsk population, observed on the annual basis, bear evidence of high activity and intensity of the foci. In this regard, a number of preventive measures is put forward, but further observations concerning all the parameters that influence foci activity are required.

PCR assays were used to test sample from Ixodes persulcatus, blood and tissues of small mammals, human blood after tick bi- tes, as well as isolates from adult ticks. It was demonstrated the presence of two Borrelia species: B. garinii and B. afzelii. Mainly DNA B. garinii NT29 were determined.

Ehrlichia muris and Anaplasma phagocytophilum DNA were detected using nested PCR among Ixodes persulcatus collected in Novosibirsk, Sverdlovsk and Chelyabinsk regions and in blood samples of small mammals from Novosibirsk and Sverdlovsk re- gions. Two genetic variants of A. phagocytophilum were revealed in blood samples and ticks from Novosibirsk region.

Determination of ticks species is very important for epidemiology and ecology investigations but in some cases the morphological study couldn't be carried out. In this work the PCR system based on species-specific primers to cytochrome oxidase subunit 1 (COI) gene sequence was developed for molecular species typing of Ixodes persulcatus and. Ixodes pavlovskyi ticks.