scholarly journals Distribution of the tick-borne encephalitis virus among naturally infected ixodid ticks and small mammals in the Novosibirsk region

2015 ◽  
Vol 20 (4) ◽  
pp. 26-34
Author(s):  
V. N Bakhvalova ◽  
G. S Chicherina ◽  
V. V Panov ◽  
V. V Glupov ◽  
O. V Morozova
Keyword(s):  
Virus Infection ◽  
Common Shrew ◽  
Far East ◽  
Carrier State ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Frequency Detection ◽  
Novosibirsk Region ◽  
Tick Borne Encephalitis ◽  
Ixodes Pavlovskyi

A comparative analysis of the virus infection carrier state and distribution of genetic types of the virus of tick-borne encephalitis (TBE) among invertebrates (2 species of ticks, Ixodes persulcatus Schulze and Ixodes pavlovskyi Pomerantsev 1946) and vertebrate reservoir hosts (4 species of small rodents: the red vole Myodes rutilus Pallas, gray-sided vole Myodes rufocanus Sundevall, field mouse Apodemus agrarius Pallas, birch mice Sicista betulina Pallas and 1 species of insectivores - common shrew Sorex araneus L (1758)), dominating on the territory of the Novosibirsk region in 2009-14 years, was performed with the use of virological and molecular biological methods. Frequency detection of RNA and / or E protein in mammals (70,9 ± 3,0%) were shown to considerably exceed levels of virus infection carrier state rate of ticks (3,4 ± 0,4). In the circulation of three major types of TBE - Far East (FE), Siberian (NIB) and European (Eur) in natural populations in mono - or polytype forms in mites Sib type prevailed (p

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.

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.

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 From the experience of combating ixodid ticks with vectors of spring-summer tick-borne encephalitis

2021 ◽  
Vol 43 (3) ◽  
pp. 5-8
Author(s):  
M. A. Smetanina
Keyword(s):  
Air Temperature ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Mixed Forests ◽  
The Third ◽  
Tick Borne Encephalitis ◽  
Mass Activity

The beginning of the activity of the tick - the vector of spring-summer encephalitis - Ixodes persulcatus in the deciduous and mixed forests of the TASSR is marked from the second decade of April at an average daily air temperature of 4-5, -1- 10.4o and an average ten-day f-6.5 , 4-8.0 . The mass activity of ticks is observed in the third decade of May and the first decade of June.

scholarly journals Ixodid ticks in Southern part of Eastern Siberia and Mongolia and their spontaneous infectiveness by infectious agents

2006 ◽  
Vol 5 ◽  
pp. 137-143
Author(s):  
G. A. Danchinova ◽  
M. A. Khasnatinov ◽  
V. I. Zlobin ◽  
I. V. Kozlova ◽  
M. M. Verkhozina ◽  
...  
Keyword(s):  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Eastern Siberia ◽  
Borrelia Garinii ◽  
Genetic Characteristics ◽  
Tick Borne Encephalitis ◽  
Vector Borne ◽  
Tick Borne Encephalitis Virus ◽  
Rickettsia Sibirica

The goal of the study is to reveal the species of Ixodid ticks in Eastern Siberia and Mongolia, having epidemiological value and pathogens that transmit to humans via their bites. The tasks is to determine ecologo-epidemiologial characteristics of the main vectors and genetic characteristics of the agents of tick-borne infections. Characterization of the materials. There are materials of the study of more than 200 000 Ixodid ticks of 4 species and their rate of infection by different pathogens with zooparasitological, epidemiological, virological, microbiological, molecular-biological standard and modified to the goals and tasks of the study. Most abundance and dangerous species is Ixodes persulcatus P.Sch. ticks, that is widespread in region investigated. The agents of known vector-borne infections in Eastern Siberia and Mongolia are tick-borne encephalitis virus, Borrelia garinii, Borrelia afze- lii, Rickettsia sibirica, R. sp. DnS14 group.

scholarly journals Detection of bartonella DNA in ixodid ticks, mosquitoes and in patients blood in Novosibirsk region

2006 ◽  
Vol 5 ◽  
pp. 106-110
Author(s):  
O. V. Morozova ◽  
L. V. Petrozhitskaya ◽  
N. Ya. Chernousova ◽  
A. G. Mirzayeva ◽  
A. K. Dobrotvorsky ◽  
...  
Keyword(s):  
Human Blood ◽  
Mixed Infection ◽  
Nested Pcr ◽  
Bartonella Henselae ◽  
Dermacentor Reticulatus ◽  
Ixodid Ticks ◽  
Ixodes Persulcatus ◽  
Bartonella Quintana ◽  
Novosibirsk Region ◽  
Pcr Product

Bartonella DNA was detected using nested PCR in ticks Ixodes persulcatus and Dermacentor reticulatus, in mosquitoes Aedes cantans, but not in other mosquito or gnat species. Phylogenic analysis of the PCR product nucleotide sequences proved the infec- tion of arthropod vectors and human blood with Bartonella henselae, Bartonella quintana or their mixed infection in Novosibirsk region.

scholarly journals Tick-borne encephalitis in the Far East focal region of the Eurasian continent

2020 ◽  
Vol 97 (2) ◽  
pp. 150-158
Author(s):  
Galina N. Leonova
Keyword(s):  
South Korea ◽  
Far East ◽  
Tien Shan ◽  
Ixodid Ticks ◽  
Focal Region ◽  
Wild Rodents ◽  
Eurasian Continent ◽  
Tick Borne Encephalitis ◽  
Natural Foci ◽  
Far Eastern

The analysis of the activity of natural foci of tick-borne encephalitis (TBE) in the Far Eastern Federal District (Primorsky and Khabarovsk Territories, the Jewish Autonomous and Amur Regions), represented by a single Sikhote-Alin focal region was performed. Endemic territories of China, Korea, Japan are adjacent to this focal region. In the last decade the decrease of the infection rate in ixodid ticks and the morbidity of TBE compared to the 1990s was observed. Data on the infection rates in ixodid ticks based on ELISA, PCR and TBEV isolation are often discrepant. Active circulation of TBEV that involved dominant and less significant species of ixodid ticks and mouse-like rodents has been demonstrated since 1952 in China, since the 1990s in Japan and since 2011 in South Korea. The circulation of TBEV strains of the Far Eastern subtype was determined in all these territories. The exception was 7 strains isolated in South Korea, which appeared to be the European subtype based on the results of molecular genetic analysis. Two new strains of TBEV from the organs of wild rodents Marmota himalayana were isolated in 2017 in the territories of previously unknown natural foci in the Tien Shan, China. The genetic divergence of these strains from three TBEV subtypes allowed us to establish the existance of a new Himalayan TBEV subtype (Him-TBEV), which, according to the authors, has been "hidden" for hundreds of years. One can also speculate the processes of emergence of new TBEV subtypes The most complete picture of the Far Eastern population of TBEV was obtained in the last decade of the twentieth century, which served as the basis and impetus for the study and comparative analysis of the differences in numerous strains of TBEV isolated on the territory of the Eurasian continent.

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