The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
N. A. Novikova - One of the best experts on this subject based on the ideXlab platform.
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Phylodynamic characteristics of the Russian population of rotavirus А (Reoviridae: Sedoreovirinae: Rotavirus) based on the VP6 gene
Voprosy virusologii, 2021Co-Authors: O. V. Morozova, T. F. Sashina, N. A. NovikovaAbstract:Introduction. Rotavirus A is one of the leading causes of acute gastroenteritis in children in the first years of life. Rotavirus infection is currently classified as a preventable infection. The most abundant rotavirion protein is VP6. Material and methods. Phylogenetic analysis and calculation of phylodynamic characteristics were carried out for 262 nucleotide sequences of the VP6 gene of rotavirus species A, isolated in Russia, using the BEAST v.1.10.4 software package. The derivation and analysis of amino acid sequences was performed using the MEGAX program. Results. This study provides phylodynamic characteristics of the rotaviruses in Russia based on the sequences coding VP6 protein. Bayesian analysis showed the circulation of rotaviruses of three sublineages of genotype I1 and three sublineages of genotype I2 in Russia. The level of accumulation of mutations was established, which turned out to be similar for genotypes I1 and I2 and amounted to 7.732E-4 and 1.008E-3 nucleotides/site/year, respectively. The effective population sizes based on nucleotide sequences of the VP6 I1 and I2 genotypes are relatively stable while after the 2000s there is a tendency of its decreasing. Comparative analysis of the amino acid sequences in the region of the intracellular neutralization sites A (231–260 aa) and B (265–292 aa) made it possible to reveal a mutation in position V252I in a proportion of Russian strains of genotype I1 some strains of genotypes I1 and I2 had mutation I281V. These substitutions were not associated with any sublineages to which the strains belong. The analysis of three T-cell epitopes revealed four amino acid differences (in aa positions 305, 315, 342, 348) that were associated with the first or second genogroup. Conclusion. Based on the phylodynamic characteristics and amino acid composition of antigenic determinants, it was concluded that the VP6 protein is highly stable and could potentially be a good model for development of a rotavirus vaccine.
Peter Mertens - One of the best experts on this subject based on the ideXlab platform.
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Encephalosis Virus
2013Co-Authors: Karin Aharonson-raz, Amir Steinman, Velizar Bumbarov, Sushila Maan, Kyriaki Nomikou, Carrie Batten, Christiaan A. Potgieter, Yuval Gottlieb, Narender Singh Maan, Peter MertensAbstract:(EEV) caused febrile outbreaks in horses. Phylogenetic analysis of segment 10 of the virus strains showed that they form a new cluster; analysis of segment 2 showed ≈92% sequence identity to EEV-3, the reference isolate. Thus, the source of this emerging EEV remains uncertain. Equine encephalosis is an arthropod-borne, noncontagious, febrile disease of horses. It was first described>100 years ago by A. Theiler (1) under the name equine ephemeral fever. The disease is caused by Equine encephalosis virus (EEV; genus Orbivirus: subfamily Sedoreovirinae: family Reoviridae) (2,3), which is transmitted by Culicoides spp. biting midges (4). Before 2008, EEV had been isolated only in South Africa, where 7 antigenically distinct serotypes, EEV-1–7, have been identified and characterized (3). Orbiviruses encode at least 7 structural and 4 nonstructural (NS) proteins from 10 linear dsRNA genome segments (5). The smallest genome segment, segment 10 (Seg-10), encodes NS3, which mediates the release of virus particles from infected cells, and NS3A. The second largest of the EEV genome segments, Seg-2, encodes virus protein (VP) 2, the larger of the 2 outer-capsid proteins. By analogy with bluetongue virus (BTV), the Orbivirus type species, the virus serotype is determined by the specificity of interactions between VP2 and neutralizing antibodies generated during infection of the mammalian host. Consequently, VP2 and Seg-2 show sequence variation
Reynoso Utrera Emmanuel - One of the best experts on this subject based on the ideXlab platform.
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IDENTIFICACIÓN MOLECULAR y FILOGENÉTICA DE ROTAVIRUS., EN CONEJOS DE LA ZONA SUR ORIENTE DEL ESTADO DE MÉXICO
'Universidad Autonoma del Estado de Mexico', 2015Co-Authors: García Rubio, Virginia G, Linda Guilina Bautista Gómez /, Romero Núñez Camilo, Reynoso Utrera EmmanuelAbstract:Rotavirus es reconocido como el agente etiológico de gastroenteritis más importante tanto en niños como en animales neonatos en todo el mundo, con una morbilidad y mortalidad de gran impacto social y económico (Dodet et al., 1997; Estes et al., 2001; Matthijinssens et al., 2008). El género Rotavirus está clasificado dentro de la familia Reoviridae, subfamilia Sedoreovirinae (Nakagomi y Nakagomi, 2002). El genoma del virus está compuesto por 11 segmentos de doble cadena de RNA, seis de ellos codifican para seis proteínas estructurales (VP1-VP4, VP6 y VP7) y cinco para seis proteínas no estructurales (NSP1-NSP6). El genoma está protegido por una cápside constituida por tres capas (Martella et al., 2005). La capa intermedia está conformada en su totalidad por la proteína VP6, esta proteína permite la clasificación antigénica de rotavirus en siete grupos (A-G), aunque Matthijnssens et al., 2012, han añadido el grupo H. En conejos se ha identificado el grupo A de Rotavirus, las cepas que pertenecen a este grupo, se clasifican en subgrupos (SG), mediante la amplificación de la región que codifica para sus determinantes antigénicos, ubicada dentro del fragmento VP6En otros países, Rotavirus es considerado la principal etiología de gastroenteritis aguda en conejos. En México, en las unidades de producción cunícola los cuadros entéricos repercuten en alta mortalidad y fuertes pérdidas económicas. La proteína VP6 de la capa intermedia de la cápside del virus, es utilizada para clasificar antigénicamente el Rotavirus en grupos (A-H). Utilizando la técnica de Reverso Transcriptasa-Reacción en Cadena de la Polimerasa, se probaron 19 muestras de intestino de conejos sanos y con cuadro clínico entérico, provenientes de la región suroriente del Estado de México, De las muestras probada el 31.5% (6), amplificaron un fragmento de 380pb utilizando los primers específicos para el fragmento VP6. Es el primer reporte de detección molecular de Rotavirus en conejos en Méxic
K. A. Yuzhakova - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of human rotavirus A (Reoviridae: Sedoreovirinae: Rotavirus: Rotavirus A) virus-like particles
Voprosy virusologii, 2021Co-Authors: S. A. Cherepushkin, A. G. Yuzhakov, Oleg Latyshev, K. P. Alekseev, E. G. Altayeva, K. M. Khametova, G. K. Vorkunova, K. A. YuzhakovaAbstract:Introduction. Rotavirus infection is the leading cause of acute gastroenteritis among infants. The development of new vaccines against rotavirus A is urgent because the virus has many genotypes, some of which have regional prevalence. Virus-like particles (VLP) is a promising way to create effective and safe vaccine preparations. The purpose of the study is to develop the technology for the production of VLP, containing VP2, VP4, VP6 and VP7 of viral genotypes prevalent on the territory of the Russian Federation, and to give its molecular genetic and virological characteristics. Material and methods . The virulent strain Wa G1P[8] of human RV A adapted to MARC-145 cell culture has been used. It was cultured and purified according to the method described by the authors earlier. Standard molecular genetic and cytological methods were used: gene synthesis; cloning into transfer plasmids; recombinant baculoviruses production in Bac-to-Bac expression system; VLP production in the insect cells; centrifugation in sucrose solution; enzyme-linked immunosorbent assay (ELISA); electron microscopy (EM); polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis. Results. VP4 and VP7 of the six most represented in Russia genotypes: G1, G2, G4, G9, P4, P8, as well as VP2 and VP6 were selected for VLP production. Recombinant baculoviruses were obtained with codon frequencies optimized for insect cells. Cabbage loopper (Trichoplusia ni) cell culture was coinfected with different combinations of baculoviruses, and VLP consisting of 2-4 proteins were produced. VLP were purified by centrifugation. The size and morphology of the particles matched the rotavirus A virion (by EM). The presence of rotavirus A proteins in VLP was confirmed by the ELISA, SDS-PAGE and western blot analysis. Conclusion. The technology for the synthesis of three-layer VLP consisting of VP2, VP4, VP6 and VP7 has been developed and optimized. The resulting VLP composition represents 6 serotypes of VP4 and VP7, which are most represented on the territory of Russia, and can be used for vaccine development.
O. V. Morozova - One of the best experts on this subject based on the ideXlab platform.
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Phylodynamic characteristics of the Russian population of rotavirus А (Reoviridae: Sedoreovirinae: Rotavirus) based on the VP6 gene
Voprosy virusologii, 2021Co-Authors: O. V. Morozova, T. F. Sashina, N. A. NovikovaAbstract:Introduction. Rotavirus A is one of the leading causes of acute gastroenteritis in children in the first years of life. Rotavirus infection is currently classified as a preventable infection. The most abundant rotavirion protein is VP6. Material and methods. Phylogenetic analysis and calculation of phylodynamic characteristics were carried out for 262 nucleotide sequences of the VP6 gene of rotavirus species A, isolated in Russia, using the BEAST v.1.10.4 software package. The derivation and analysis of amino acid sequences was performed using the MEGAX program. Results. This study provides phylodynamic characteristics of the rotaviruses in Russia based on the sequences coding VP6 protein. Bayesian analysis showed the circulation of rotaviruses of three sublineages of genotype I1 and three sublineages of genotype I2 in Russia. The level of accumulation of mutations was established, which turned out to be similar for genotypes I1 and I2 and amounted to 7.732E-4 and 1.008E-3 nucleotides/site/year, respectively. The effective population sizes based on nucleotide sequences of the VP6 I1 and I2 genotypes are relatively stable while after the 2000s there is a tendency of its decreasing. Comparative analysis of the amino acid sequences in the region of the intracellular neutralization sites A (231–260 aa) and B (265–292 aa) made it possible to reveal a mutation in position V252I in a proportion of Russian strains of genotype I1 some strains of genotypes I1 and I2 had mutation I281V. These substitutions were not associated with any sublineages to which the strains belong. The analysis of three T-cell epitopes revealed four amino acid differences (in aa positions 305, 315, 342, 348) that were associated with the first or second genogroup. Conclusion. Based on the phylodynamic characteristics and amino acid composition of antigenic determinants, it was concluded that the VP6 protein is highly stable and could potentially be a good model for development of a rotavirus vaccine.