scholarly journals Comparative analysis of the tick-borne encephalitis virus (TBEV) infection of unfed adult ixodid ticks Ixodes pavlovsky Pomerantsev 1946 and Ixodes persulcatus Schulze in the area of sympatria of their natural habitats

2015 ◽  
Vol 20 (1) ◽  
pp. 20-26
Author(s):  
G. S Chicherina ◽  
O. V Morozova ◽  
V. V Panov ◽  
V. N Romanenko ◽  
S. A Bakhvalov ◽  
...  
Keyword(s):  
Encephalitis Virus ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Anthropogenic Pressure ◽  
Laboratory Mice ◽  
Natural Habitats ◽  
Tick Borne Encephalitis ◽  
Ixodes Pavlovskyi ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection

With the use of the ELISA method to detect an antigen, reverse transcription with quantitative real-time PCR with subtype-specific fluorescent probes, phylogenetic analysis of E and NS1 gene nucleotide sequences, bioassays with suckling mice, hemagglutination and neuroinvasiveness tests there was made a comparison of the tick-borne encephalitis virus (TBEV) infection of ixodid ticks Ixodes persulcatus P.Schulze and Ixodes pavlovskyi Pomerantsev 1946 in the area of sympatria of their natural habitats in the Novosibirsk region during growth period of their populations with the replacement ofprevailing species of monodominant type of the ixodid population structure. The ratio of 2 tick species didn’t depend on biotopes ofpine or birch forest but rather on the distance from the Novosibirsk Scientific Center: the lower anthropogenic pressure the smaller I.pavlovskyi proportion. The TBEV rate (including both pathogenic and apathogenic for laboratory mice virus), spectra of the TBEV3 main genetic types, neurovirulence and hemagglutination activity were similarfor both I.persulcatus and I.pavlovskyi. However, the proportion ofpathogenic for laboratory mice virus and the TBEV Far Eastern subtype, as well as viral loads of Siberian and European types for the TBEV from I.pavlovskyi were significantly higher than those from I.persulcatus.

Analysis of laboratory methods for monitoring of tick-borne encephalitis natural foci

2021 ◽  
pp. 26-32
Author(s):  
Olga Vitalievna Melnikova ◽  
Yuliya Nikolaevna Trushina ◽  
Renat Viktorovich Adelshin ◽  
Nikolay Vasilievich Yakovchits ◽  
Evgeniy Ivanovich Andaev ◽  
...  
Keyword(s):  
Baikal Region ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Isolation And Identification ◽  
Tick Borne Encephalitis ◽  
Natural Foci ◽  
Group 2 ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection ◽  
Group 1

Introduction. Ixodid ticks simultaneously are hosts and vectors of tick-borne encephalitis virus (TBEV), presenting a high risk to humans. Monitoring of the vectors part of TBEV population is usually held by means of express analysis methods (ELISA and PCR), but only isolation and identification of infectious virus is reliable evidence of TBEV circulation in the natural foci. Objectives — to demonstrate the TBEV infection rates of Ixodid ticks from natural TBE foci of Baikal Region, based on comprehensive study, including ELISA, PCR and isolation of virus on laboratory mice (LM) model. Methods. Questing adult Ixodid ticks (n = 20 111, mainly — Ixodes persulcatus Schulze, 1930), were collected in TBE natural foci of Baikal Region during 2013–2020. The suspension on saline solution was prepared from the each tick and analyzed by ELISA first. The samples with positive ELISA results were verified in PCR-RT. Furthermore, randomly selected samples with negative ELISA results were analyzed by PCR. Suspensions with positive ELISA and PCR results have been inoculated to suckling LM intracerebrally. Results. The samples with positive PCR results have been divided into two groups: group 1 — all suspensions with positive ELISA results, group 2 — randomly selected samples with negative ELISA results. The positive PCR results in group 1 made up 70.5 % with average Ct rate 24.9. The positive PCR results in group 2 have been obtained in 2.2 % of cases with average Ct rate 30.7. The isolation on LM model was more successful in group 1 (25.8 vs 13.0 %; р < 0.01; df = 69). Conclusion. ELISA is more useful for study of large amounts of ticks during monitoring of natural TBE foci, offering insight into the epidemically important vectors rate. To get the more full assessment of the ticks’ infection rate one must use ELISA and PCR simultaneously, and sum the results into general rate. For high strains isolation results the LM should be inoculated with the suspensions, which had shown positive both ELISA and PCR results.

scholarly journals Tick-borne encephalitis virus – a review of an emerging zoonosis

2009 ◽  
Vol 90 (8) ◽  
pp. 1781-1794 ◽  
Author(s):  
K. L. Mansfield ◽  
N. Johnson ◽  
L. P. Phipps ◽  
J. R. Stephenson ◽  
A. R. Fooks ◽  
...  
Keyword(s):  
Clinical Manifestations ◽  
Northern China ◽  
Encephalitis Virus ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Tick Borne Encephalitis ◽  
Far Eastern Russia ◽  
Tick Borne Encephalitis Virus ◽  
Far Eastern

During the last 30 years, there has been a continued increase in human cases of tick-borne encephalitis (TBE) in Europe, a disease caused by tick-borne encephalitis virus (TBEV). TBEV is endemic in an area ranging from northern China and Japan, through far-eastern Russia to Europe, and is maintained in cycles involving Ixodid ticks (Ixodes ricinus and Ixodes persulcatus) and wild vertebrate hosts. The virus causes a potentially fatal neurological infection, with thousands of cases reported annually throughout Europe. TBE has a significant mortality rate depending upon the strain of virus or may cause long-term neurological/neuropsychiatric sequelae in people affected. In this review, we comprehensively reviewed TBEV, its epidemiology and pathogenesis, the clinical manifestations of TBE, along with vaccination and prevention. We also discuss the factors which may have influenced an apparent increase in the number of reported human cases each year, despite the availability of effective vaccines.

scholarly journals Infection and injury of human astrocytes by tick-borne encephalitis virus

2014 ◽  
Vol 95 (11) ◽  
pp. 2411-2426 ◽  
Author(s):  
Martin Palus ◽  
Tomáš Bílý ◽  
Jana Elsterová ◽  
Helena Langhansová ◽  
Jiří Salát ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Encephalitis Virus ◽  
Ultrastructural Changes ◽  
Interferon Α ◽  
Human Astrocytes ◽  
Tick Borne Encephalitis ◽  
Infected Cells ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection ◽  
Pro Inflammatory Cytokines

Tick-borne encephalitis (TBE), a disease caused by tick-borne encephalitis virus (TBEV), represents the most important flaviviral neural infection in Europe and north-eastern Asia. In the central nervous system (CNS), neurons are the primary target for TBEV infection; however, infection of non-neuronal CNS cells, such as astrocytes, is not well understood. In this study, we investigated the interaction between TBEV and primary human astrocytes. We report for the first time, to the best of our knowledge, that primary human astrocytes are sensitive to TBEV infection, although the infection did not affect their viability. The infection induced a marked increase in the expression of glial fibrillary acidic protein, a marker of astrocyte activation. In addition, expression of matrix metalloproteinase 9 and several key pro-inflammatory cytokines/chemokines (e.g. tumour necrosis factor α, interferon α, interleukin (IL)-1β, IL-6, IL-8, interferon γ-induced protein 10, macrophage inflammatory protein, but not monocyte chemotactic protein 1) was upregulated. Moreover, we present a detailed description of morphological changes in TBEV-infected cells, as investigated using three-dimensional electron tomography. Several novel ultrastructural changes were observed, including the formation of unique tubule-like structures of 17.9 ±0.15 nm diameter with associated viral particles and/or virus-induced vesicles and located in the rough endoplasmic reticulum of the TBEV-infected cells. This is the first demonstration that TBEV infection activates primary human astrocytes. The infected astrocytes might be a potential source of pro-inflammatory cytokines in the TBEV-infected brain, and might contribute to the TBEV-induced neurotoxicity and blood–brain barrier breakdown that occurs during TBE. The neuropathological significance of our observations is also discussed.

scholarly journals A Functional Toll-Like Receptor 3 Gene (TLR3) May Be a Risk Factor for Tick-borne Encephalitis Virus (TBEV) Infection

2011 ◽  
Vol 203 (4) ◽  
pp. 523-528 ◽  
Author(s):  
Elin Kindberg ◽  
Sirkka Vene ◽  
Aukse Mickiene ◽  
Åke Lundkvist ◽  
Lars Lindquist ◽  
...  
Keyword(s):  
Risk Factor ◽  
Encephalitis Virus ◽  
Toll Like Receptor ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection

scholarly journals Nucleoside Inhibitors of Tick-Borne Encephalitis Virus

2015 ◽  
Vol 59 (9) ◽  
pp. 5483-5493 ◽  
Author(s):  
Luděk Eyer ◽  
James J. Valdés ◽  
Victor A. Gil ◽  
Radim Nencka ◽  
Hubert Hřebabecký ◽  
...  
Keyword(s):  
Neuroblastoma Cells ◽  
Antiviral Effect ◽  
Encephalitis Virus ◽  
Nucleoside Analogues ◽  
Kidney Cells ◽  
Porcine Kidney ◽  
Human Neuroblastoma ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection

ABSTRACTTick-borne encephalitis virus (TBEV) is a leading cause of human neuroinfections in Europe and Northeast Asia. There are no antiviral therapies for treating TBEV infection. A series of nucleoside analogues was tested for the ability to inhibit the replication of TBEV in porcine kidney cells and human neuroblastoma cells. The interactions of three nucleoside analogues with viral polymerase were simulated using advanced computational methods. The nucleoside analogues 7-deaza-2′-C-methyladenosine (7-deaza-2′-CMA), 2′-C-methyladenosine (2′-CMA), and 2′-C-methylcytidine (2′-CMC) inhibited TBEV replication. These compounds showed dose-dependent inhibition of TBEV-induced cytopathic effects, TBEV replication (50% effective concentrations [EC50]of 5.1 ± 0.4 μM for 7-deaza-2′-CMA, 7.1 ± 1.2 μM for 2′-CMA, and 14.2 ± 1.9 μM for 2′-CMC) and viral antigen production. Notably, 2′-CMC was relatively cytotoxic to porcine kidney cells (50% cytotoxic concentration [CC50] of ∼50 μM). The anti-TBEV effect of 2′-CMA in cell culture diminished gradually after day 3 posttreatment. 7-Deaza-2′-CMA showed no detectable cellular toxicity (CC50> 50 μM), and the antiviral effect in culture was stable for >6 days posttreatment. Computational molecular analyses revealed that compared to the other two compounds, 7-deaza-2′-CMA formed a large cluster near the active site of the TBEV polymerase. High antiviral activity and low cytotoxicity suggest that 7-deaza-2′-CMA is a promising candidate for further investigation as a potential therapeutic agent in treating TBEV infection.

Tick-Borne Encephalitis Virus Diversity in Ixodid Ticks and Small Mammals in South-Western Siberia, Russia

2016 ◽  
Vol 16 (8) ◽  
pp. 541-549 ◽  
Author(s):  
Valentina N. Bakhvalova ◽  
Galina S. Chicherina ◽  
Olga F. Potapova ◽  
Victor V. Panov ◽  
Victor V. Glupov ◽  
...  
Keyword(s):  
Small Mammals ◽  
Western Siberia ◽  
Encephalitis Virus ◽  
Ixodid Ticks ◽  
Virus Diversity ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus

scholarly journals Comparative analysis of genomes of tick-borne encephalitis virus strains isolated from mosquitoes and ticks

2017 ◽  
Vol 62 (1) ◽  
pp. 30-35 ◽  
Author(s):  
N. M. Pukhovskaya ◽  
O. V. Morozova ◽  
N. B. Belozerova ◽  
S. V. Bakhmetyeva ◽  
N. P. Vysochina ◽  
...  
Keyword(s):  
Vaccine Strain ◽  
Far East ◽  
Encephalitis Virus ◽  
Ixodes Persulcatus ◽  
Aedes Vexans ◽  
Tick Borne Encephalitis ◽  
Tbev Strain ◽  
Natural Foci ◽  
Tick Borne Encephalitis Virus ◽  
Far Eastern

The tick-borne encephalitis virus (TBEV) strain Lazo MP36 was isolated from the pool of mosquitoes Aedes vexans collected in Lazo region of Khabarovsk territory in August 2014. Phylogenetic analysis of the strain Lazo MP36 complete genome (GenBank accession number KT001073) revealed its correspondence to the TBEV Far Eastern subtype and differences from the following strains: 1) from ticks Ixodes persulcatus P. Schulze, 1930 [vaccine strain 205 (JX498939) and strains Khekhtzir 1230 (KF880805), Chichagovka (KP844724), Birobidzhan 1354 (KF880805) isolated in 2012-2013]; 2) from mosquitoes [strain Malyshevo (KJ744034) isolated in 1978 from Aedes vexans nipponii in Khabarovsk territory; strain Sakhalin 6-11 isolated from the pool of mosquitoes in 2011 (KF826916)]; 3) from human brain [vaccine strain Sofjin (JN229223), Glubinnoe/2004(DQ862460). Kavalerovo (DQ862460), Svetlogorie (DQ862460)]. The fusion peptide necessary for flavivirus entry to cells of the three TBEV strains isolated from mosquitoes (Lazo MP36, Malyshevo and Sakhalin 6-11) has the canonical structure 98-DRGWGNHCGLFGKGSI-113 for the tick-borne flaviviruses. Amino acid transition H104G typical for the mosquito-borne flaviviruses was not found. Structures of 5’- and 3’-untranslated (UTR) regions of the TBEV strains from mosquitoes were 85-98% homologous to the TBEV strains of all subtypes without recombination with mosquito-borne flaviviruses found in the Far East of Russia. Secondary structures of 5’- and 3'-UTR as well as cyclization sequences (CS) of types a and B are highly homologous for all TBEV isolates independently of the biological hosts and vectors. similarity of the genomes of the TBEV isolates from mosquitoes, ticks and patients as well as pathogenicity of the isolates for new-borne laboratory mice and tissue cultures might suggest a possible role of mosquitoes in the TBEV circulation in natural foci as an accidental or additional virus carrier.

Properties of the tick-borne encephalitis virus population during persistent infection of ixodid ticks and tick cell lines

2017 ◽  
Vol 8 (6) ◽  
pp. 895-906 ◽  
Author(s):  
Oxana A. Belova ◽  
Alexander G. Litov ◽  
Ivan S. Kholodilov ◽  
Liubov I. Kozlovskaya ◽  
Lesley Bell-Sakyi ◽  
...  
Keyword(s):  
Cell Lines ◽  
Persistent Infection ◽  
Encephalitis Virus ◽  
Ixodid Ticks ◽  
Virus Population ◽  
Tick Cell ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus

TBE in France

2019 ◽  
Author(s):  
Yves Hansmann ◽  
Aurélie Velay
Keyword(s):  
Human Case ◽  
Encephalitis Virus ◽  
Eastern Region ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus ◽  
Tbev Infection

The first human case of tick-borne encephalitis virus (TBEV) infection in France was reported in 1968 in Alsace, an eastern region next to the German border: a gamekeeper working in a forest near Strasbourg.

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