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Sample records for bunyaviridae

  1. Viruses of the family Bunyaviridae: are all available isolates reassortants?

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    Briese, Thomas; Calisher, Charles H; Higgs, Stephen

    2013-11-01

    Viruses of the family Bunyaviridae (the bunyaviruses) possess three distinct linear, single-stranded, negative sense or ambisense RNA segments (large, medium, and small). Dual infections of arthropod and perhaps vertebrate and plant hosts provide substantial opportunity for segment reassortment and an increasingly recognized number of the nearly 300 viruses in this family have been shown to be reassortants. Reassortment of RNA segments (genetic shift) complements genetic drift (accumulation of point mutations) as a powerful mechanism underlying bunyavirus evolution. Here we consider the possibility, if not likelihood, that most if not all bunyaviruses currently recognized may represent reassortants, some of which may be reassortants of existing viruses, and some of which may be reassortants of extinct viruses. If this hypothesis is correct, then the roots of the family and genus trees of bunyaviruses as currently described (or ignored) are incomplete or incorrect. © 2013 Elsevier Inc. All rights reserved.

  2. Biogeography of Tick-Borne Bhanja Virus (Bunyaviridae in Europe

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    Zdenek Hubálek

    2009-01-01

    Full Text Available Bhanja virus (BHAV is pathogenic for young domestic ruminants and also for humans, causing fever and affections of the central nervous system. This generally neglected arbovirus of the family Bunyaviridae is transmitted by metastriate ticks of the genera Haemaphysalis, Dermacentor, Hyalomma, Rhipicephalus, Boophilus, and Amblyomma. Geographic distribution of BHAV covers southern and Central Asia, Africa, and southern (partially also central Europe. Comparative biogeographic study of eight known natural foci of BHAV infections in Europe (in Italy, Croatia, Bulgaria, Slovakia has revealed their common features. (1 submediterranean climatic pattern with dry growing season and wet mild winter (or microlimatically similar conditions, e.g., limestone karst areas in central Europe, (2 xerothermic woodland-grassland ecosystem, with plant alliances Quercetalia pubescentis, Festucetalia valesiacae, and Brometalia erecti, involving pastoral areas, (3 presence of at least one of the tick species Haemaphysalis punctata, Dermacentor marginatus, Rhipicephalus bursa, and/or Hyalomma marginatum, and (4 presence of ≥60% of the 180 BHAV bioindicator (157 plant, 4 ixodid tick, and 19 vertebrate spp.. On that basis, Greece, France (southern, including Corsica, Albania, Spain, Hungary, European Turkey, Ukraine (southern, Switzerland (southern, Austria (southeastern, Germany (southern, Moldova, and European Russia (southern have been predicted as additional European regions where BHAV might occur.

  3. The VirusBanker database uses a Java program to allow flexible searching through Bunyaviridae sequences

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    Fourment, Mathieu; Gibbs, Mark J

    2008-01-01

    Background Viruses of the Bunyaviridae have segmented negative-stranded RNA genomes and several of them cause significant disease. Many partial sequences have been obtained from the segments so that GenBank searches give complex results. Sequence databases usually use HTML pages to mediate remote sorting, but this approach can be limiting and may discourage a user from exploring a database. Results The VirusBanker database contains Bunyaviridae sequences and alignments and is presented as two spreadsheets generated by a Java program that interacts with a MySQL database on a server. Sequences are displayed in rows and may be sorted using information that is displayed in columns and includes data relating to the segment, gene, protein, species, strain, sequence length, terminal sequence and date and country of isolation. Bunyaviridae sequences and alignments may be downloaded from the second spreadsheet with titles defined by the user from the columns, or viewed when passed directly to the sequence editor, Jalview. Conclusion VirusBanker allows large datasets of aligned nucleotide and protein sequences from the Bunyaviridae to be compiled and winnowed rapidly using criteria that are formulated heuristically. PMID:18251994

  4. Culicoides sonorensis (Diptera: Ceratopogonidae) is not a competent vector of Cache Valley virus (family Bunyaviridae, genus Orthobunyavirus).

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    Reeves, Will K; Miller, Myrna M

    2013-10-01

    We investigated the susceptibility of Culicoides sonorensis to Cache Valley virus (CVV) (family Bunyaviridae, genus Orthobunyavirus) infection and the potential that it could be a vector or site of virus reassortment. CVV is native to the New World and causes disease in livestock. Infected blood meals were fed to both a competent vector, Anopheles quadrimaculatus, and Culicoides sonorensis. All Anopheles mosquitoes were infected as expected, but only 21 % of the C. sonorensis insects were susceptible to infection. These appeared to present a midgut barrier, because virus persisted but did not disseminate. This means Culicoides sonorensis is not likely to be a vector of CVV but could be involved in viral reassortment. Schmallenberg virus (SBV) (family Bunyaviridae, genus Orthobunyavirus) was recently discovered in Europe and probably is a novel virus resulting from a reassortment of two orthobunyaviruses, and an ongoing epizootic in cattle and small ruminants has caused significant economic damage.

  5. Isolation of Madre de Dios Virus (Orthobunyavirus; Bunyaviridae), an Oropouche Virus Species Reassortant, from a Monkey in Venezuela

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    Navarro, Juan-Carlos; Giambalvo, Dileyvic; Hernandez, Rosa; Auguste, Albert J.; Tesh, Robert B.; Weaver, Scott C.; Montañez, Humberto; Liria, Jonathan; Lima, Anderson; da Rosa, Jorge Fernando Soares Travassos; da Silva, Sandro P.; Vasconcelos, Janaina M.; Oliveira, Rodrigo; Vianez, João L. S. G.; Nunes, Marcio R. T.

    2016-01-01

    Oropouche virus (OROV), genus Orthobunyavirus, family Bunyaviridae, is an important cause of human illness in tropical South America. Herein, we report the isolation, complete genome sequence, genetic characterization, and phylogenetic analysis of an OROV species reassortant, Madre de Dios virus (MDDV), obtained from a sick monkey (Cebus olivaceus Schomburgk) collected in a forest near Atapirire, a small rural village located in Anzoategui State, Venezuela. MDDV is one of a growing number of naturally occurring OROV species reassortants isolated in South America and was known previously only from southern Peru. PMID:27215299

  6. Iris yellow spot virus (Tospovirus: Bunyaviridae): from obscurity to research priority.

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    Bag, Sudeep; Schwartz, Howard F; Cramer, Christopher S; Havey, Michael J; Pappu, Hanu R

    2015-04-01

    Iris yellow spot virus (IYSV) is in the genus Tospovirus, family Bunyaviridae, with a single-stranded, tri-segmented RNA genome with an ambisense genome organization. Members of the other genera in the family infect predominantly vertebrates and insects. IYSV is present in most Allium-growing regions of the world. Virions are pleomorphic particles of 80-120 nm in size. The particle consists of RNA, protein, glycoprotein and lipids. IYSV shares the genomic features of other tospoviruses: a segmented RNA genome of three RNAs, referred to as large (L), medium (M) and small (S). The L RNA codes for the RNA-dependent RNA polymerase (RdRp) in negative sense. The M RNA uses an ambisense coding strategy and codes for the precursor for the GN /GC glycoprotein in the viral complementary (vc) sense and a non-structural protein (NSm) in the viral (v) sense. The S RNA also uses an ambisense coding strategy with the coat protein (N) in vc sense and a non-structural protein (NSs) in the v sense. The virus is transmitted by Thrips tabaci Lindeman (Order: Thysanoptera; Family: Thripidae; onion thrips) and with less efficiency by Frankliniella fusca Hinds (tobacco thrips). HOST: IYSV has a relatively broad host range, including cultivated and wild onions, garlic, chives, leeks and several ornamentals. Some weeds are naturally infected by IYSV and may serve as alternative hosts for the virus. IYSV symptoms in Allium spp. are yellow- to straw-coloured, diamond-shaped lesions on leaves and flowering scapes. Diamond-shaped lesions are particularly pronounced on scapes. As the disease progresses, the lesions coalesce, leading to lodging of the scapes. In seed crops, this could lead to a reduction in yield and quality. Early to mid-season infection in bulb crops results in reduced vigour and bulb size. Resistant varieties are not available, but a limited number of accessions with field tolerance have been identified. Integrated disease management tactics, including sanitation, crop

  7. Teratogenicity of Australian Simbu serogroup and some other Bunyaviridae viruses: the embryonated chicken egg as a model.

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    McPhee, D A; Parsonson, I M; Della-Porta, A J; Jarrett, R G

    1984-01-01

    The use of embryonated chicken eggs as a model for assessing the teratogenic potential of animal viruses was investigated with 12 members of the Bunyaviridae family. Infection of 4-day-old embryonated chicken eggs via the yolk sac with 10 of the viruses resulted in deaths or congenital deformities that were similar to those observed in Akabane virus infections of fetal ruminants and included arthrogryposis, scoliosis, mandible defects, and retarded development. Statistical analysis showed that the viruses fell into three main groupings, namely, those that caused both death and deformities (Akabane, Aino, Tinaroo, and Belmont viruses), those that mainly caused death (Peaton, Thimiri, and Facey's Paddock viruses), and those that required very high doses to cause either death or deformities (Douglas and CSIR0296 viruses). In addition, two viruses (Kowanyama and Mapputta viruses) caused neither death nor deformities. A difference in the pathogenic potential between two Akabane isolates (B8935 and CSIR016) in the embryonated chicken egg model was found to correlate with differences previously observed in experimentally infected sheep; Akabane CSIR016 was the more pathogenic. It is concluded that the embryonated chicken egg model should also be of value in assessing the teratogenic potential of other Bunyaviridae and attenuated vaccine viruses, although it does not assess the ability of the virus to cross the placenta.

  8. Caracterização e relacionamento antigênico de três novos Bunyavirus no grupo Anopheles A (Bunyaviridae dos arbovirus Characterization and antigenic relationship of three new Bunyavirus in the Anopheles A serogroup (Bunyaviridae of arboviruses

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    Jorge Fernando Soares Travassos da Rosa

    1992-06-01

    Full Text Available São descritos o isolamento e a caracterização de três novos arbovirus isolados na região da Usina Hidro-Elétrica de Tucuruí (UHE-TUC. Os três novos arbovirus pertencem ao grupo Anopheles A(ANA, gênero Bunyavirus (família Bunyaviridae. Os vírus Tucuruí (TUC, Caraipé (CPE e Arumateua (ART são relacionados entre si e com o vírus Trombetas (TBT, formando dentro do grupo ANA um complexo chamado Trombetas. Os arbovirus TUC, CPE e ART foram obtidos a partir de lotes de mosquitos Anopheles (Nyssorhynchus sp capturados em Tucuruí, nas proximidades da usina hidrelétrica de Tucuruí, Estado do Pará, nos meses de fevereiro, agosto e outubro de 1984, respectivamente. Até o final de 1990 os vírus TUC, CPE e ART foram isolados 12, 32 e 28 vezes respectivamente, sempre na região da UHE-TUC, exceção feita ao vírus TUC, do qual se obteve uma amostra procedente de Balbina, onde também foi construída uma hidroelétrica. Até o presente, esses vírus só foram isolados a partir de mosquitos do grupo An. (Nys. principalmente, a partir das espécies An. (Nys. nuneztovari e An. (Nys. triannulatus também consideradas vetores secundários da malária na Amazônia Brasileira. Testes sorológicos executados com soros humanos e de diversas espécies de animais silvestres foram negativos, com exceção de um soro de um carnívoro de espécie Nasua nasua que neutralizou a amostra TUC em títulos de 2.6 índice logaritmico de neutralização (ILN.The isolation and characterization of three new viruses obtained from the Tucuruí hydroelectric dam region is repeated. These three agents belong to the Anopheles A serogroup, genus Bunyavirus, Bunyaviridae. The Tucuruí (TUC, Caraipe (CPE and Arumateua (ART viruses have close relationships with each other and with Trombetas (TBT virus, an Anopheles A virus previously isolated in the Amazon Region of Brazil. These viruses form the "Trombetas complex". TUC, CPE and ART viruses were obtained from pools of

  9. Determination of whether tomato spotted wilt virus replicates in Toxorhynchites amboinensis mosquitoes and the relatedness of this virus to phleboviruses (family Bunyaviridae).

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    Wang, M; Mitchell, C J; Hu, J S; Gonsalves, D; Calisher, C H

    1992-01-01

    Tomato spotted wilt virus (TSWV) has been reported to be morphologically, molecularly and structurally similar to viruses in the family Bunyaviridae. By various types of enzyme-linked immunosorbent assays (ELISA) and Western blot hybridizations, we tested TSWV with antibodies to 12 viruses in the Phlebovirus genus of this family. Serological relatedness was not found between TSWV and phleboviruses. However, one preparation of antibody to Arumowot virus reacted with a 53-kD protein from healthy plant extracts. Six-day-old adult Toxorhynchites amboinensis mosquitoes were inoculated with purified TSWV. Infectious virus was not detected in any of the injected insects during the 5-week test period. However, TSWV antigens were detected in these mosquitoes by ELISA at the original injected level for at least a week after injection. TSWV antigen concentration began to decrease thereafter, but remained at detectable levels for as long as 5 weeks after injection. However, there was no evidence that TSWV replicated in mosquitoes.

  10. [Taxonomic status of the Burana virus (BURV) (Bunyaviridae, Nairovirus, Tamdy group) isolated from the ticks Haemaphysalis punctata Canestrini et Fanzago, 1877 and Haem. concinna Koch, 1844 (Ixodidae, Haemaphysalinae) in Kyrgyzstan].

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    L'vov, D K; Al'khovskiĭ, S V; Shchelkanov, M Iu; Shchetinin, A M; Deriabin, P G; Gitel'man, A K; Aristova, V A; Botikov, A G

    2014-01-01

    Complete genome sequence of the Burana virus (BURV) was determined using the next-generation sequencing approach (ID GenBank KF801651). The prototype strain of BURV LEIV-Krg760 was originally isolated from the ticks Haemaphysalis punctata Canestrini et Fanzago, 1877 (Ixodidae, Haemaphysalinae), collected from cows in Tokmak wildlife sanctuary, eastern part of the Chu valley (43 degrees 10' N, 74 degrees 40' E) near Burana village, Kirgizia, in April 1971. Molecular genetics and phylogenetic analyses showed that the BURV belonged to the Nairovirus genus, Bunyaviridae and is related to Tamdy virus (TAMV) that is also associated with the ixodidae ticks of pasture biocenosis in Central Asia. Previous studies showed that TAMV is the prototypic virus of new phylogenetic Tamdy group in the Nairovirus genus. Thus, BURV was classified as a new virus of the Tamdy group, Nairovirus, Bunyaviridae.

  11. In vivo localization of iris yellow spot tospovirus (Bunyaviridae-encoded proteins and identification of interacting regions of nucleocapsid and movement proteins.

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    Diwaker Tripathi

    Full Text Available Localization and interaction studies of viral proteins provide important information about their replication in their host plants. Tospoviruses (Family Bunyaviridae are economically important viruses affecting numerous field and horticultural crops. Iris yellow spot virus (IYSV, one of the tospoviruses, has recently emerged as an important viral pathogen of Allium spp. in many parts of the world. We studied the in vivo localization and interaction patterns of the IYSV proteins in uninfected and infected Nicotiana benthamiana and identified the interacting partners.Bimolecular fluorescence complementation (BiFC analysis demonstrated homotypic and heterotypic interactions between IYSV nucleocapsid (N and movement (NSm proteins. These interactions were further confirmed by pull-down assays. Additionally, interacting regions of IYSV N and NSm were identified by the yeast-2-hybrid system and β-galactosidase assay. The N protein self-association was found to be mediated through the N- and C-terminal regions making head to tail interaction. Self-interaction of IYSV NSm was shown to occur through multiple interacting regions. In yeast-2-hybrid assay, the N- and C-terminal regions of IYSV N protein interacted with an N-terminal region of IYSV NSm protein.Our studies provide new insights into localization and interactions of IYSV N and NSm proteins. Molecular basis of these interactions was studied and is discussed in the context of tospovirus assembly, replication, and infection processes.

  12. In vivo localization of iris yellow spot tospovirus (Bunyaviridae)-encoded proteins and identification of interacting regions of nucleocapsid and movement proteins.

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    Tripathi, Diwaker; Raikhy, Gaurav; Goodin, Michael M; Dietzgen, Ralf G; Pappu, Hanu R

    2015-01-01

    Localization and interaction studies of viral proteins provide important information about their replication in their host plants. Tospoviruses (Family Bunyaviridae) are economically important viruses affecting numerous field and horticultural crops. Iris yellow spot virus (IYSV), one of the tospoviruses, has recently emerged as an important viral pathogen of Allium spp. in many parts of the world. We studied the in vivo localization and interaction patterns of the IYSV proteins in uninfected and infected Nicotiana benthamiana and identified the interacting partners. Bimolecular fluorescence complementation (BiFC) analysis demonstrated homotypic and heterotypic interactions between IYSV nucleocapsid (N) and movement (NSm) proteins. These interactions were further confirmed by pull-down assays. Additionally, interacting regions of IYSV N and NSm were identified by the yeast-2-hybrid system and β-galactosidase assay. The N protein self-association was found to be mediated through the N- and C-terminal regions making head to tail interaction. Self-interaction of IYSV NSm was shown to occur through multiple interacting regions. In yeast-2-hybrid assay, the N- and C-terminal regions of IYSV N protein interacted with an N-terminal region of IYSV NSm protein. Our studies provide new insights into localization and interactions of IYSV N and NSm proteins. Molecular basis of these interactions was studied and is discussed in the context of tospovirus assembly, replication, and infection processes.

  13. Isolations of Jamestown Canyon virus (Bunyaviridae: Orthobunyavirus) from field-collected mosquitoes (Diptera: Culicidae) in Connecticut, USA: a ten-year analysis, 1997-2006.

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    Andreadis, Theodore G; Anderson, John F; Armstrong, Philip M; Main, Andrew J

    2008-04-01

    Jamestown Canyon virus (JCV) (Bunyaviridae: Orthobunyavirus) is a mosquito-borne zoonosis belonging to the California serogroup. It has a wide geographic distribution, occurring throughout much of temperate North America. White-tailed deer, Odocoileus virginianus are the principal amplification hosts, and boreal Aedes and Ochlerotatus mosquitoes are the primary vectors. A 10-year study was undertaken to identify potential mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the geographic distribution of JCV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. Jamestown Canyon virus was isolated from 22 mosquito species. Five of them, Ochlerotatus canadensis, Oc. cantator, Anopheles punctipennis, Coquillettidia perturbans, and Oc. abserratus were incriminated as the most likely vectors, based on yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Jamestown Canyon virus was isolated from Oc. canadensis more consistently and from a greater range of collection sites than any other species. Frequent virus isolations were also made from Aedes cinereus, Aedes vexans, and Oc. sticticus, and new North American isolation records were established for Anopheles walkeri, Culex restuans, Culiseta morsitans, Oc. sticticus, Oc. taeniorhynchus, and Psorophora ferox. Other species from which JCV was isolated included C. melanura, Oc. aurifer, Oc. communis, Oc. excrucians, Oc. provocans, Oc. sollicitans, Oc. stimulans, Oc. triseriatus, and Oc. trivittatus. Jamestown Canyon virus was widely distributed throughout Connecticut and found to consistently circulate in a diverse array of mosquito vectors. Infected mosquitoes were collected from June through September, and peak infection rates paralleled mosquito abundance from mid-June through mid-July. Infection rates in mosquitoes were consistent from year to year, and overall virus

  14. Sequence characterization, molecular phylogeny reconstruction and recombination analysis of the large RNA of Tomato spotted wilt virus (Tospovirus: Bunyaviridae) from the United States.

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    Ramesh, Shunmugiah V; Pappu, Hanu R

    2016-04-01

    Tomato spotted wilt virus (TSWV; Tospovirus: Bunyaviridae) has been an economically important virus in the USA for over 30 years. However the complete sequence of only one TSWV isolate PA01 characterized from pepper in Pennsylvania is available. The large (L) RNA of a TSWV WA-USA isolate was cloned and sequenced. It consisted of 8914 nucleotides (nt) encoding a single open reading frame of 8640 nts in the viral-complementary sense. The ORF potentially codes for RNA-dependent RNA polymerase (RdRp) of 330.9 kDa. Two untranslated regions of 241 and 33 nucleotides were present at the 5' and 3' termini, respectively that shared conserved tospoviral sequences. Phylogenetic analysis using nucleotide sequences of the complete L RNA showed that TSWV WA-USA isolate clustered with the American and Asian TSWV isolates which formed a distinct clade from Euro-Asiatic Tospoviruses. Phylogeny of the amino acid sequence of all tospoviral RdRps used in this study showed that all the known TSWV isolates including the USA isolate described in this study formed a distinct and a close cluster with that of Impateins necrotic spot virus. Multiple sequence alignment revealed conserved motifs in the RdRp of TSWV. Recombination analysis identified two recombinants including the TSWV WA-USA isolate. Among them, three recombination events were detected in the conserved motifs of the RdRp. Sequence analysis and phylogenetic analysis of the L RNA showed distinct clustering with selected TSWV isolates reported from elsewhere. Conserved motifs in the core polymerase region of the RdRp and recombination events were identified.

  15. Caracterização e relacionamento antigênico de três novos Bunyavirus no grupo Anopheles A (Bunyaviridae dos arbovirus

    Directory of Open Access Journals (Sweden)

    Jorge Fernando Soares Travassos da Rosa

    1992-06-01

    Full Text Available São descritos o isolamento e a caracterização de três novos arbovirus isolados na região da Usina Hidro-Elétrica de Tucuruí (UHE-TUC. Os três novos arbovirus pertencem ao grupo Anopheles A(ANA, gênero Bunyavirus (família Bunyaviridae. Os vírus Tucuruí (TUC, Caraipé (CPE e Arumateua (ART são relacionados entre si e com o vírus Trombetas (TBT, formando dentro do grupo ANA um complexo chamado Trombetas. Os arbovirus TUC, CPE e ART foram obtidos a partir de lotes de mosquitos Anopheles (Nyssorhynchus sp capturados em Tucuruí, nas proximidades da usina hidrelétrica de Tucuruí, Estado do Pará, nos meses de fevereiro, agosto e outubro de 1984, respectivamente. Até o final de 1990 os vírus TUC, CPE e ART foram isolados 12, 32 e 28 vezes respectivamente, sempre na região da UHE-TUC, exceção feita ao vírus TUC, do qual se obteve uma amostra procedente de Balbina, onde também foi construída uma hidroelétrica. Até o presente, esses vírus só foram isolados a partir de mosquitos do grupo An. (Nys. principalmente, a partir das espécies An. (Nys. nuneztovari e An. (Nys. triannulatus também consideradas vetores secundários da malária na Amazônia Brasileira. Testes sorológicos executados com soros humanos e de diversas espécies de animais silvestres foram negativos, com exceção de um soro de um carnívoro de espécie Nasua nasua que neutralizou a amostra TUC em títulos de 2.6 índice logaritmico de neutralização (ILN.

  16. Caracterização e relacionamento antigênico de três novos Bunyavirus no grupo Anopheles A (Bunyaviridae dos arbovirus

    Directory of Open Access Journals (Sweden)

    Rosa Jorge Fernando Soares Travassos da

    1992-01-01

    Full Text Available São descritos o isolamento e a caracterização de três novos arbovirus isolados na região da Usina Hidro-Elétrica de Tucuruí (UHE-TUC. Os três novos arbovirus pertencem ao grupo Anopheles A(ANA, gênero Bunyavirus (família Bunyaviridae. Os vírus Tucuruí (TUC, Caraipé (CPE e Arumateua (ART são relacionados entre si e com o vírus Trombetas (TBT, formando dentro do grupo ANA um complexo chamado Trombetas. Os arbovirus TUC, CPE e ART foram obtidos a partir de lotes de mosquitos Anopheles (Nyssorhynchus sp capturados em Tucuruí, nas proximidades da usina hidrelétrica de Tucuruí, Estado do Pará, nos meses de fevereiro, agosto e outubro de 1984, respectivamente. Até o final de 1990 os vírus TUC, CPE e ART foram isolados 12, 32 e 28 vezes respectivamente, sempre na região da UHE-TUC, exceção feita ao vírus TUC, do qual se obteve uma amostra procedente de Balbina, onde também foi construída uma hidroelétrica. Até o presente, esses vírus só foram isolados a partir de mosquitos do grupo An. (Nys. principalmente, a partir das espécies An. (Nys. nuneztovari e An. (Nys. triannulatus também consideradas vetores secundários da malária na Amazônia Brasileira. Testes sorológicos executados com soros humanos e de diversas espécies de animais silvestres foram negativos, com exceção de um soro de um carnívoro de espécie Nasua nasua que neutralizou a amostra TUC em títulos de 2.6 índice logaritmico de neutralização (ILN.

  17. Spatial-Temporal Analysis of Cache Valley Virus (Bunyaviridae: Orthobunyavirus) Infection in Anopheline and Culicine Mosquitoes (Diptera: Culicidae) in the Northeastern United States, 1997–2012

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    Armstrong, Philip M.; Anderson, John F.; Main, Andrew J.

    2014-01-01

    Abstract Cache Valley virus (CVV) is a mosquito-borne bunyavirus (family Bunyaviridae, genus Orthobunyavirus) that is enzootic throughout much of North and Central America. White-tailed deer (Odocoileus virginianus) have been incriminated as important reservoir and amplification hosts. CVV has been found in a diverse array of mosquito species, but the principal vectors are unknown. A 16-year study was undertaken to identify the primary mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the spatial geographic distribution of CVV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. CVV was isolated from 16 mosquito species in seven genera, almost all of which were multivoltine and mammalophilic. Anopheles (An.) punctipennis was incriminated as the most consistent and likely vector in this region on the basis of yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Other species exhibiting frequent temporal and moderate spatial geographic patterns of virus isolation within the state included Ochlerotatus (Oc.) trivittatus, Oc. canadensis, Aedes (Ae.) vexans, and Ae. cinereus. New isolation records for CVV were established for An. walkeri, Culiseta melanura, and Oc. cantator. Other species from which CVV was isolated included An. quadrimaculatus, Coquillettidia perturbans, Culex salinarius, Oc. japonicus, Oc. sollicitans, Oc. taeniorhynchus, Oc. triseriatus, and Psorophora ferox. Mosquitoes infected with CVV were equally distributed throughout urban, suburban, and rural locales, and infection rates were not directly associated with the localized abundance of white-tailed deer, possibly due to their saturation throughout the region. Virus activity in mosquitoes was episodic with no consistent pattern from year-to-year, and fluctuations in yearly seasonal infection rates did not appear to be directly impacted by

  18. Spatial-temporal analysis of Cache Valley virus (Bunyaviridae: Orthobunyavirus) infection in anopheline and culicine mosquitoes (Diptera: Culicidae) in the northeastern United States, 1997-2012.

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    Andreadis, Theodore G; Armstrong, Philip M; Anderson, John F; Main, Andrew J

    2014-10-01

    Cache Valley virus (CVV) is a mosquito-borne bunyavirus (family Bunyaviridae, genus Orthobunyavirus) that is enzootic throughout much of North and Central America. White-tailed deer (Odocoileus virginianus) have been incriminated as important reservoir and amplification hosts. CVV has been found in a diverse array of mosquito species, but the principal vectors are unknown. A 16-year study was undertaken to identify the primary mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the spatial geographic distribution of CVV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. CVV was isolated from 16 mosquito species in seven genera, almost all of which were multivoltine and mammalophilic. Anopheles (An.) punctipennis was incriminated as the most consistent and likely vector in this region on the basis of yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Other species exhibiting frequent temporal and moderate spatial geographic patterns of virus isolation within the state included Ochlerotatus (Oc.) trivittatus, Oc. canadensis, Aedes (Ae.) vexans, and Ae. cinereus. New isolation records for CVV were established for An. walkeri, Culiseta melanura, and Oc. cantator. Other species from which CVV was isolated included An. quadrimaculatus, Coquillettidia perturbans, Culex salinarius, Oc. japonicus, Oc. sollicitans, Oc. taeniorhynchus, Oc. triseriatus, and Psorophora ferox. Mosquitoes infected with CVV were equally distributed throughout urban, suburban, and rural locales, and infection rates were not directly associated with the localized abundance of white-tailed deer, possibly due to their saturation throughout the region. Virus activity in mosquitoes was episodic with no consistent pattern from year-to-year, and fluctuations in yearly seasonal infection rates did not appear to be directly impacted by overall

  19. Bunyaviridae and Their Replication. Part 2. Replication of Bunyaviridae

    Science.gov (United States)

    1990-01-01

    required for the glycoproteins of viruses causing hemorrhagic fever with renal formation of 3’ termini of sea urchin M24 mRNA. Cell syndrome (HFRS...Schmaljohn and Jean L. Patterson i M oAttachment and Entry, 1183Virion Morphology and Structure, 1175 Transcription, 1184 Morphology , 1175...group of arthropod-borne viruses CCHF, and La Crosse (LAC), but many are not known sharing morphological , morphogenic, and antigenic to infect humans

  20. [Taxonomic status of the Chim virus (CHIMV) (Bunyaviridae, Nairovirus, Qalyub group) isolated from the Ixodidae and Argasidae ticks collected in the great gerbil (Rhombomys opimus Lichtenstein, 1823) (Muridae, Gerbillinae) burrows in Uzbekistan and Kazakhstan].

    Science.gov (United States)

    L'vov, D K; Al'khovskiĭ, S V; Shchelkanov, M Iu; Shchetinin, A M; Aristova, V A; Morozova, T N; Gitel'man, A K; Deriabin, P G; Botikov, A G

    2014-01-01

    Full-length genome of the Chim virus (CHIMV) (strain LEIV-858Uz) was sequenced using the next-generation sequencing approach (ID GenBank: KF801656). The CHIMV/LEIV-858Uz was isolated from the Ornithodoros tartakovskyi Olenev, 1931 ticks collected in the great gerbil (Rhombomys opimus Lichtenstein, 1823) burrow in Uzbekistan near Chim town (Kashkadarinsky region) in July of 1971. Later, four more CHIMV strains were isolated from the O. tartakovskyi, O. papillipes Birula, 1895, Rhipicephalus turanicus Pomerantsev, 1936 collected in the great gerbil burrows in Kashkadarinsky, Bukhara, and Syrdarya regions of Uzbekistan, and three strains--from the Hyalomma asiaticum Schulze et Schlottke, 1930 from the great gerbil burrows in Dzheskazgan region of Kazakhstan. The virus is a potential pathogen of humans and camels. The phylogenetic analysis revealed that the CHIMV is a novel member of the Nairovirus genus (Bunyaviridae) and closely related to the Qalyub virus (QYBV), which is prototype for the group of the same name. The amino acid homology between the CHIMV and QYBV is 87% for the RdRp catalytic center (L-segment) that is coincident with both QYBV and CHIMV associated with the Ornithodoros ticks and burrow of rodents as well. The CHIMV homologies with other nairoviruses are 30-40% for the amino acid sequences of precursor polyprotein GnGc (M-segment), whereas 50%--for the nucleocapsid N (S-segment). The data obtained permit to classify the CHIMV as a member of the QYBV group in the genus of Nairovirus (Bunyaviridae).

  1. Partial genetic characterization of Sedlec virus (Orthobunyavirus, Bunyaviridae)

    Czech Academy of Sciences Publication Activity Database

    Bakonyi, T.; Kolodziejek, J.; Rudolf, Ivo; Berčič, R.; Nowotny, N.; Hubálek, Zdeněk

    2013-01-01

    Roč. 19, October (2013), s. 244-249 ISSN 1567-1348 Institutional support: RVO:68081766 Keywords : Sedlec virus * Leanyer virus * Simbu group * Orthobunyavirus * Acrocephalus Subject RIV: EE - Microbiology, Virology Impact factor: 3.264, year: 2013

  2. Genomic Characterization of the Genus Nairovirus (Family Bunyaviridae)

    Science.gov (United States)

    Kuhn, Jens H.; Wiley, Michael R.; Rodriguez, Sergio E.; Bào, Yīmíng; Prieto, Karla; Travassos da Rosa, Amelia P. A.; Guzman, Hilda; Savji, Nazir; Ladner, Jason T.; Tesh, Robert B.; Wada, Jiro; Jahrling, Peter B.; Bente, Dennis A.; Palacios, Gustavo

    2016-01-01

    Nairovirus, one of five bunyaviral genera, includes seven species. Genomic sequence information is limited for members of the Dera Ghazi Khan, Hughes, Qalyub, Sakhalin, and Thiafora nairovirus species. We used next-generation sequencing and historical virus-culture samples to determine 14 complete and nine coding-complete nairoviral genome sequences to further characterize these species. Previously unsequenced viruses include Abu Mina, Clo Mor, Great Saltee, Hughes, Raza, Sakhalin, Soldado, and Tillamook viruses. In addition, we present genomic sequence information on additional isolates of previously sequenced Avalon, Dugbe, Sapphire II, and Zirqa viruses. Finally, we identify Tunis virus, previously thought to be a phlebovirus, as an isolate of Abu Hammad virus. Phylogenetic analyses indicate the need for reassignment of Sapphire II virus to Dera Ghazi Khan nairovirus and reassignment of Hazara, Tofla, and Nairobi sheep disease viruses to novel species. We also propose new species for the Kasokero group (Kasokero, Leopards Hill, Yogue viruses), the Ketarah group (Gossas, Issyk-kul, Keterah/soft tick viruses) and the Burana group (Wēnzhōu tick virus, Huángpí tick virus 1, Tǎchéng tick virus 1). Our analyses emphasize the sister relationship of nairoviruses and arenaviruses, and indicate that several nairo-like viruses (Shāyáng spider virus 1, Xīnzhōu spider virus, Sānxiá water strider virus 1, South Bay virus, Wǔhàn millipede virus 2) require establishment of novel genera in a larger nairovirus-arenavirus supergroup. PMID:27294949

  3. Aguacate virus, a new antigenic complex of the genus Phlebovirus (family Bunyaviridae).

    Science.gov (United States)

    Palacios, Gustavo; da Rosa, Amelia Travassos; Savji, Nazir; Sze, Wilson; Wick, Ivan; Guzman, Hilda; Hutchison, Stephen; Tesh, Robert; Lipkin, W Ian

    2011-06-01

    Genomic and antigenic characterization of Aguacate virus, a tentative species of the genus Phlebovirus, and three other unclassified viruses, Armero virus, Durania virus and Ixcanal virus, demonstrate a close relationship to one another. They are distinct from the other nine recognized species within the genus Phlebovirus. We propose to designate them as a new (tenth) serogroup or species (Aguacate virus) within the genus. The four viruses were all isolated from phlebotomine sandflies (Lutzomyia sp.) collected in Central and South America. Aguacate virus appears to be a natural reassortant and serves as one more example of the high frequency of reassortment in this genus.

  4. Cross-neutralization study of seven California group (Bunyaviridae) strains in homoiothermous (PS) and poikilothermous (XTC-2) vertebrate cells.

    Science.gov (United States)

    Hubálek, Z; Chanas, A C; Johnson, B K; Simpson, D I

    1979-02-01

    Antigenic relationships among seven California group strains were studied by a plaque-reduction neutralization test (PRNT). Cross-reactions occurred in most cases but three subgroups were noted: (1) the major serogroup contained the viruses of California encephalitis, LaCrosse, Snowshoe Hare and Trahyna (including the Lumbo strain) whereas (2) Jamestown Canyon and (3) Trivittatus viruses were distinct. There was no significant difference between the PRNT results in mammalian (PS) cells incubated at 37 degrees C and amphibian (XTC-2) cells incubated at 28 degrees C. Trivittatus virus failed to produce plaques in XTC-2 cells.

  5. Pneumonitis in Syrian golden hamsters (Mesocricetus auratus) infected with Rio Mamoré virus (family Bunyaviridae, genus Hantavirus).

    Science.gov (United States)

    Milazzo, Mary Louise; Eyzaguirre, Eduardo J; Fulhorst, Charles F

    2014-10-13

    Rio Mamoré virus is an etiological agent of hantavirus pulmonary syndrome in South America. The purpose of this study was to determine whether Rio Mamoré virus strain HTN-007 in Syrian golden hamsters is pathogenic. None of 37 adult hamsters infected by intramuscular injection of HTN-007, including 10 animals killed on Day 42 or 43 post-inoculation, exhibited any symptom of disease. Histological abnormalities included severe or moderately severe pneumonitis in 6 (46.2%) of the 13 animals killed on Day 7 or 10 post-inoculation. The primary target of infection in lung was the endothelium of the microvasculature. Collectively, these results indicate that Rio Mamoré virus strain HTN-007 in adult Syrian golden hamsters can cause a nonlethal disease that is pathologically similar to hantavirus pulmonary syndrome. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Pneumonitis in Syrian golden hamsters (Mesocricetus auratus) infected with Río Mamoré virus (family Bunyaviridae, genus Hantavirus)

    Science.gov (United States)

    Milazzo, Mary Louise; Eyzaguirre, Eduardo J.; Fulhorst, Charles F.

    2014-01-01

    Rio Mamoré virus is an etiological agent of hantavirus pulmonary syndrome in South America. The purpose of this study was to determine whether Rio Mamoré virus strain HTN-007 in Syrian golden hamsters is pathogenic. None of 37 adult hamsters infected by intramuscular injection of HTN-007, including 10 animals killed on Day 42 or 43 post-inoculation, exhibited any symptom of disease. Histological abnormalities included severe or moderately severe pneumonitis in 6 (46.2%) of the 13 animals killed on Day 7 or 10 post-inoculation. The primary target of infection in lung was the endothelium of the microvasculature. Collectively, these results indicate that Rio Mamoré virus strain HTN-007 in adult Syrian golden hamsters can cause a nonlethal disease that is pathologically similar to hantavirus pulmonary syndrome. PMID:25064267

  7. Human and Murine IFIT1 Proteins Do Not Restrict Infection of Negative-Sense RNA Viruses of the Orthomyxoviridae, Bunyaviridae, and Filoviridae Families

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Amelia K.; Williams, Graham D.; Szretter, Kristy J.; White, James P.; Proença-Módena, José Luiz; Liu, Gai; Olejnik, Judith; Brien, James D.; Ebihara, Hideki; Mühlberger, Elke; Amarasinghe, Gaya; Diamond, Michael S.; Boon, Adrianus C. M.; Doms, R. W.

    2015-07-08

    Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) is a host protein with reported cell-intrinsic antiviral activity against several RNA viruses. The proposed basis for the activity against negative-sense RNA viruses is the binding to exposed 5'-triphosphates (5'-ppp) on the genome of viral RNA. However, recent studies reported relatively low binding affinities of IFIT1 for 5'-ppp RNA, suggesting that IFIT1 may not interact efficiently with this moiety under physiological conditions. To evaluate the ability of IFIT1 to have an impact on negative-sense RNA viruses, we infectedIfit1-/-and wild-type control mice and primary cells with four negative-sense RNA viruses (influenza A virus [IAV], La Crosse virus [LACV], Oropouche virus [OROV], and Ebola virus) corresponding to three distinct families. Unexpectedly, a lack ofIfit1gene expression did not result in increased infection by any of these viruses in cell culture. Analogously, morbidity, mortality, and viral burdens in tissues were identical betweenIfit1-/-and control mice after infection with IAV, LACV, or OROV. Finally, deletion of the human IFIT1 protein in A549 cells did not affect IAV replication or infection, and reciprocally, ectopic expression of IFIT1 in HEK293T cells did not inhibit IAV infection. To explain the lack of antiviral activity against IAV, we measured the binding affinity of IFIT1 for RNA oligonucleotides resembling the 5' ends of IAV gene segments. The affinity for 5'-ppp RNA was approximately 10-fold lower than that for non-2'-O-methylated (cap 0) RNA oligonucleotides. Based on this analysis, we conclude that IFIT1 is not a dominant restriction factor against negative-sense RNA viruses.

    IMPORTANCENegative-sense RNA viruses, including influenza virus and Ebola virus, have been responsible for some of the most deadly outbreaks in recent history. The host interferon response and induction of antiviral genes contribute to the control of infections by these viruses. IFIT1 is highly induced after virus infection and reportedly has antiviral activity against several RNA and DNA viruses. However, its role in restricting infection by negative-sense RNA viruses remains unclear. In this study, we evaluated the ability of IFIT1 to inhibit negative-sense RNA virus replication and pathogenesis bothin vitroandin vivo. Detailed cell culture and animal studies demonstrated that IFIT1 is not a dominant restriction factor against three different families of negative-sense RNA viruses.

  8. Global analysis of population structure, spatial and temporal dynamics of genetic diversity, and evolutionary lineages of Iris yellow spot virus (Tospovirus: Bunyaviridae).

    Science.gov (United States)

    Iftikhar, Romana; Ramesh, Shunmugiah V; Bag, Sudeep; Ashfaq, Muhammad; Pappu, Hanu R

    2014-08-15

    Thrips-transmitted Iris yellow spot virus is an economically important viral pathogen of Allium crops worldwide. A global analysis of known IYSV nucleocapsid gene (N gene) sequences was carried out to determine the comparative population structure, spatial and temporal dynamics with reference to its genetic diversity and evolution. A total of 98 complete N gene sequences (including 8 sequences reported in this study) available in GenBank and reported from 23 countries were characterized by in-silico RFLP analysis. Based on RFLP, 94% of the isolates could be grouped into NL or BR types while the rest belonged to neither group. The relative proportion of NL and BR types was 46% and 48%, respectively. A temporal shift in the IYSV genotypes with a greater incremental incidence of IYSVBR was found over IYSVNL before 2005 compared to after 2005. The virus population had at least one evolutionarily significant recombination event, involving IYSVBR and IYSVNL. Codon substitution studies did not identify any significant differences among the genotypes of IYSV. However, N gene codons were minimally positively selected, moderately negatively selected denoting the action of purifying selection, thus rejecting the theory of neutral mutation in IYSV population. However, one codon position (139) was found to be positively selected in all the genotypes. Population selection statistics in the IYSVBR, IYSVNL genotypes and in the population as a whole also revealed the action of purifying selection or population expansion, whereas IYSVother displayed a decrease in population size. Genetic differentiation studies showed inherent differentiation and infrequent gene flow between IYSVBR and IYSVNL genotypes corroborating the geographical confinement of these genotypes. Taken together the study suggests that the observed diversity in IYSV population and temporal shift in IYSVBR genotype is attributable to genetic recombination, abundance of purifying selection, insignificant positive selection and population expansion. Restricted gene flow between the two major IYSV genotypes further emphasizes the role of genetic drift in modeling the population architecture, evolutionary lineage and epidemiology of IYSV. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Immunoprecipitation of a 50-kDa protein: a candidate receptor component for tomato spotted wilt tospovirus (Bunyaviridae) in its main vector, Frankliniella occidentalis.

    Science.gov (United States)

    Medeiros, R B; Ullman, D E; Sherwood, J L; German, T L

    2000-04-01

    A 50-kDa protein that binds to viral particles in solid-phase assays and that is recognized by anti-idiotypic antibodies made against anti-viral glycoproteins G1/G2 (anti-Ids) has been proposed as a receptor candidate for tomato spotted wilt tospovirus (TSWV) in its main thrips vector, Frankliniella occidentalis Pergande (Bandla et al., 1998. Phytopathology 88, 98-104). Here we show the immunoprecipitation of the 50-kDa protein by anti-Ids and by an anti-G1/G2-TSWV conjugate - a new immunoprecipitation method. In addition, we show that anti-Ids made against anti-G1 (anti-IdG1) block virus replication in an insect tissue replication assay. The results indicate that (a) the TSWV-50-kDa protein interaction occurs in solution, as it must do in vivo; (b) G1 is a viral attachment protein; and (c) the 50-kDa protein is a candidate host factor essential for TSWV entry. These results provide additional support for the role of the 50-kDa thrips protein as a viral receptor. Additionally these experiments provide the basis for testing saturable binding and represent an important step toward the first cloning and identification of a cellular receptor for a plant virus.

  10. Long-Distance Dispersal Potential for Onion Thrips (Thysanoptera: Thripidae) and Iris yellow spot virus (Bunyaviridae: Tospovirus) in an Onion Ecosystem.

    Science.gov (United States)

    Smith, Erik A; Fuchs, M; Shields, E J; Nault, B A

    2015-08-01

    Onion thrips, Thrips tabaci Lindeman, is a worldwide pest of onion whose feeding damage and transmission of Iris yellow spot virus (IYSV) may reduce onion yields. Little is known about the seasonal dynamics of T. tabaci dispersal, the distance of dispersal, or the movement of thrips infected with IYSV during the onion-growing season. To address these questions, T. tabaci adults were collected using transparent sticky card traps in commercial onion fields three times during the onion-growing season (June, July, and late August) at varying heights above the canopy (0.5-6 m above soil surface) and with trap-equipped unmanned aircraft (UAVs) flying 50-60 m above onion fields during August sampling periods in 2012 and 2013. Randomly selected subsamples of captured T. tabaci were tested for IYSV using RT-PCR. Most T. tabaci adults were captured in late August and near the onion canopy (<2 m) throughout the season. However, 4% of T. tabaci adults captured on sticky cards were at altitudes ≥2 m, and T. tabaci were also captured on UAV-mounted traps. These data strongly suggest that long-distance dispersal occurs. More T. tabaci captured on sticky cards tested positive for IYSV in August (53.6%) than earlier in the season (2.3 to 21.5% in June and July, respectively), and 20 and 15% of T. tabaci captured on UAV-mounted traps tested positive for IYSV in 2012 and 2013, respectively. Our results indicate that T. tabaci adults, including viruliferous individuals, engage in long-distance dispersal late in the season and likely contribute to the spread of IYSV. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Role of Anopheles quadrimaculatus and Coquillettidia perturbans (Diptera: Culicidae) in the transmission cycle of Cache Valley virus (Bunyaviridae: Bunyavirus) in the midwest, USA.

    Science.gov (United States)

    Blackmore, C G; Blackmore, M S; Grimstad, P R

    1998-09-01

    Midwestern populations of Coquillettidia perturbans (Walker) and Anopheles quadrimaculatus (Say) were tested for their ability to transmit Cache Valley virus (CV), a recognized human and animal pathogen. Field-collected mosquitoes were fed artificial blood meals containing 5.2-6.2 log10 pfu/ml of CV. After 9-23 d at 28 degrees C, 75-93% of blood-fed Cq. perturbans had disseminated infections and 6-62% transmitted the virus to suckling mice. However, when infected with a lower virus titer (3.3 log10 pfu/ml), only 10-36% of the mosquitoes had disseminated infections and 0-10% transmitted the virus to suckling mice. A similar infection rate (21%) was observed in Cq. perturbans fed on viremic (3.2 log10 pfu/ml) hamsters. An. quadrimaculatus were infected (81-100%) by both doses used, with transmission rates ranging from 13-67% after 16-23 d of incubation. Transmission rates for the laboratory strain An. quadrimaculatus SAVANNAH ranged from 20 to 33% after 7-14 d of incubation. Our data show that although An. quadrimaculatus is more susceptible to CV infections than Cq. perturbans, both mosquito species could be involved in the midwestern transmission cycle of the virus.

  12. Mutational analysis of two highly conserved motifs in the silencing suppressor encoded by tomato spotted wilt virus (genus Tospovirus, family Bunyaviridae).

    Science.gov (United States)

    Zhai, Ying; Bag, Sudeep; Mitter, Neena; Turina, Massimo; Pappu, Hanu R

    2014-06-01

    Tospoviruses cause serious economic losses to a wide range of field and horticultural crops on a global scale. The NSs gene encoded by tospoviruses acts as a suppressor of host plant defense. We identified amino acid motifs that are conserved in all of the NSs proteins of tospoviruses for which the sequence is known. Using tomato spotted wilt virus (TSWV) as a model, the role of these motifs in suppressor activity of NSs was investigated. Using site-directed point mutations in two conserved motifs, glycine, lysine and valine/threonine (GKV/T) at positions 181-183 and tyrosine and leucine (YL) at positions 412-413, and an assay to measure the reversal of gene silencing in Nicotiana benthamiana line 16c, we show that substitutions (K182 to A, and L413 to A) in these motifs abolished suppressor activity of the NSs protein, indicating that these two motifs are essential for the RNAi suppressor function of tospoviruses.

  13. Molecular differences in the mitochondrial cytochrome oxidase I (mtCOI) gene and development of a species-specific marker for onion thrips, Thrips tabaci Lindeman, and melon thrips, T. palmi Karny (Thysanoptera: Thripidae), vectors of tospoviruses (Bunyaviridae).

    Science.gov (United States)

    Asokan, R; Krishna Kumar, N K; Kumar, Vikas; Ranganath, H R

    2007-10-01

    A quick and developmental-stage non-limiting method of the identification of vectors of tospoviruses, such as Thrips tabaci and T. palmi, is important in the study of vector transmission, insecticide resistance, biological control, etc. Morphological identification of these thrips vectors is often a stumbling block in the absence of a specialist and limited by polymorphism, sex, stage of development, etc. Molecular identification, on the other hand, is not hampered by the above factors and can easily be followed by a non-specialist with a little training. The mitochondrial cytochrome oxidase I (mtCOI) exhibits reliable inter-species variations as compared to the other markers. In this communication, we present the differences in the mtCOI partial sequence of morphologically identified specimens of T. tabaci and T. palmi collected from onion and watermelon, respectively. Species-specific markers, identified in this study, could successfully determine T. tabaci and T. palmi, which corroborated the morphological identification. Phylogenetic analyses showed that both T. tabaci and T. palmi formed different clades as compared to the other NCBI accessions. The implication of these variations in vector efficiency has to be investigated further. The result of this investigation is useful in the quick identification of T. tabaci and T. palmi, a critical factor in understanding the epidemiology of the tospoviruses, their management and also in quarantine.

  14. Planning for Rift Valley fever virus: use of geographical information systems to estimate the human health threat of white-tailed deer (Odocoileus virginianus)-related transmission

    National Research Council Canada - National Science Library

    Kakani, Sravan; LaBeaud, A Desirée; King, Charles H

    2010-01-01

    Rift Valley fever (RVF) virus is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt and the Arabian Peninsula...

  15. Haemorrhagic Fevers, Viral

    Science.gov (United States)

    ... is usually applied to disease caused by Arenaviridae (Lassa fever, Junin and Machupo), Bunyaviridae (Crimean-Congo haemorrhagic ... fever Dengue and severe dengue Ebola virus disease Lassa fever Marburg haemorrhagic fever Rift Valley fever Multimedia, ...

  16. Arbovirus infections and viral haemorrhagic fevers in Uganda: a serological survey in Karamoja district, 1984.

    Science.gov (United States)

    Rodhain, F; Gonzalez, J P; Mercier, E; Helynck, B; Larouze, B; Hannoun, C

    1989-01-01

    Sera collected in May 1984 from 132 adult residents of Karamoja district, Uganda, were examined by haemagglutination inhibition tests for antibodies against selected arboviruses, namely Chikungunya and Semliki Forest alphaviruses (Togaviridae); dengue type 2, Wesselsbron, West Nile, yellow fever and Zika flaviviruses (Flaviviridae); Bunyamwera, Ilesha and Tahyna bunyaviruses (Bunyaviridae); and Sicilian sandfly fever phlebovirus (Bunyaviridae); and by immunofluorescence tests against certain haemorrhagic fever viruses, Lassa fever arenavirus (Arenaviridae), Ebola-Sudan, Ebola-Zaïre and Marburg filoviruses (Filoviridae), Crimean-Congo haemorrhagic fever nairovirus and Rift Valley fever phlebovirus (Bunyaviridae). Antibodies against Chikungunya virus were the most prevalent (47%), followed by flavivirus antibodies (16%), which were probably due mainly to West Nile virus. No evidence of yellow fever or dengue virus circulation was observed. A few individuals had antibodies against Crimean-Congo haemorrhagic fever, Lassa, Ebola and Marburg viruses, suggesting that these viruses all circulate in the area.

  17. Early Bunyavirus-Host Cell Interactions

    Directory of Open Access Journals (Sweden)

    Amelina Albornoz

    2016-05-01

    Full Text Available The Bunyaviridae is the largest family of RNA viruses, with over 350 members worldwide. Several of these viruses cause severe diseases in livestock and humans. With an increasing number and frequency of outbreaks, bunyaviruses represent a growing threat to public health and agricultural productivity globally. Yet, the receptors, cellular factors and endocytic pathways used by these emerging pathogens to infect cells remain largely uncharacterized. The focus of this review is on the early steps of bunyavirus infection, from virus binding to penetration from endosomes. We address current knowledge and advances for members from each genus in the Bunyaviridae family regarding virus receptors, uptake, intracellular trafficking and fusion.

  18. Management of diseases caused by thrips-transmitted tospoviruses in subsistence agriculture: the case of Peanut bud necrosis virus in India

    Science.gov (United States)

    Among the tospoviruses (genus Tospovirus, family Bunyaviridae) reported in India, Peanut bud necrosis virus is by far the most economically significant for tomato production in subsistence agriculture. Management of PBNV has been a challenge for farmers due to the broad host-range of PBNV and its ve...

  19. Isolations of Bwamba virus from south central Uganda and north ...

    African Journals Online (AJOL)

    Background: Bwamba virus (Genus Bunyavirus, family Bunyaviridae) is widely distributed in Africa. It causes many unidentified fevers because of its benign nature. Objectives: Samples of blood from patients were received at Uganda Virus Research Institute for diagnosis and confirmation of infections. Mosquito collections ...

  20. Tomato spotted wilt virus particle assembly : studying the role of the structural proteins in vivo

    NARCIS (Netherlands)

    Snippe, M.

    2006-01-01

    Members of the Bunyaviridae have spherical, enveloped virus particles that acquire their lipid membrane at the Golgi complex. For the animal-infecting bunyaviruses, virus assembly involves budding of ribonucleoprotein particles (RNPs) into vacuolised lumen of the Golgi complex, after which the

  1. Spinach: A new natural host of Impatiens necrotic spot virus in California.

    Science.gov (United States)

    Impatiens necrotic spot tospovirus (INSV; family Bunyaviridae) was detected in a spinach (Spinacia oleracea) experimental field in Monterey County, CA in October of 2008. Spinach plants exhibiting severe stunting and with leaves that showed interveinal yellowing, thickening, and deformation were obs...

  2. The role of NSm during tomato spotted wilt virus infection

    NARCIS (Netherlands)

    Storms, M.M.H.

    1998-01-01

    In the past ten years the genome organisation of tomato spotted wilt virus (TSWV) has been intensively studied in our laboratory. Complete genome sequence data revealed that this enveloped plant virus belongs to the Bunyaviridae, a virus family further restricted to

  3. Virus - vector relationships in the transmission of tospoviruses

    NARCIS (Netherlands)

    Wijkamp, I.

    1995-01-01

    Tomato spotted wilt virus (TSWV), member of the genus Tospovirus within the family Bunyaviridae, ranks among the top ten of economically most important plant viruses. Tospoviruses cause significant yield losses in agricultural crops such as tomato,

  4. Viral RNA silencing suppression

    NARCIS (Netherlands)

    Hedil, Marcio; Kormelink, Richard

    2016-01-01

    The Bunyaviridae is a family of arboviruses including both plant-and vertebrate-infecting representatives. The Tospovirus genus accommodates plant-infecting bunyaviruses, which not only replicate in their plant host, but also in their insect thrips vector during persistent propagative

  5. Emerging new poleroviruses and tospoviruses affecting vegetables in Asia and breeding for resistance

    NARCIS (Netherlands)

    Relevante, C.; Cheewachaiwit, S.; Chuapong, J.; Stratongjun, M.; Salutan, V.E.; Peters, D.; Balatero, C.H.; Hoop, de S.J.

    2012-01-01

    The diseases caused by aphid-borne poleroviruses (genus Polerovirus, family Luteoviridae) and thrips-borne tospoviruses (genus Tospovirus, family Bunyaviridae) are emerging threats to the production of economically important vegetable and fruit crops in tropical and sub-tropical Asia. To date, at

  6. Molecular epidemiology of Crimean- Congo hemorrhagic fever virus genome isolated from ticks of Hamadan province of Iran

    DEFF Research Database (Denmark)

    Tahmasebi, F; Ghiasi, Seyed Mojtaba; Mostafavi, E

    2010-01-01

    BACKGROUND & OBJECTIVES: Crimean-Congo hemorrhagic fever (CCHF) virus is a tick-borne member of the genus Nairovirus, family Bunyaviridae. CCHFV has been isolated from at least 31 different tick species. The virus is transmitted through the bite of an infected tick, or by direct contact with CCHF...

  7. Rift Valley Fever Virus Growth Curve Kinetics in Cattle and Sheep Peripheral Blood Monocyte Derived Macrophages

    Science.gov (United States)

    Rift Valley fever virus (RVFV), is a mosquito-borne, zoonotic pathogen within genus Phlebovirus, family Bunyaviridae that typically causes outbreaks in sub-Saharan Africa and recently spread to the Arabian Peninsula. In ruminants, RVFV infections cause mass abortion and high mortality rates in neona...

  8. Severe Crimean-Congo haemorrhagic fever presented with massive retroperitoneal haemorrhage that recovered without antiviral treatment

    DEFF Research Database (Denmark)

    Gharabaghi, Mehrnaz Asadi; Chinikar, Sadegh; Ghiasi, Seyyed Mojtaba

    2011-01-01

    Crimean-Congo haemorrhagic fever (CCHF) is a tickborne viral zoonosis with up to 50% mortality in humans caused by CCHF virus belonging to the genus Nairovirus, family Bunyaviridae. The geographical distribution of CCHF cases corresponds closely with the distribution of principle tick vectors...

  9. Disease: H00389 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ndrome (HFRS) is a group of diseases caused by hantaviruses which are members of family Bunyaviridae. HFRS i...s characterized by renal failure, hemorrhages, and shock and is caused by the serotypes Hantaan, Seoul, Puum...ala, and Dobrava-Belgrade viruses. The serotype Puumala virus also causes nephrop

  10. Occurrence of Tomato spotted wilt virus in Stevia rebaudiana and Solanum tuberosum in Northern Greece

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Lolas, P.

    2007-01-01

    Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Greece during 1972 (3) and currently is widespread in the central and northern part of the country infecting several cultivated and wild plant species (1,2). In June 2006, virus-like symptoms similar to

  11. Four-segmented Rift Valley fever virus induces sterile immunity in sheep after a single vaccination

    NARCIS (Netherlands)

    Wichgers Schreur, P.J.; Kant-Eenbergen, H.C.M.; Keulen, van L.J.M.; Moormann, R.J.M.; Kortekaas, J.A.

    2015-01-01

    Rift Valley fever virus (RVFV), a mosquito-borne virus in the Bunyaviridae family, causes recurrent outbreaks with severe disease in ruminants and occasionally humans. The virus comprises a segmented genome consisting of a small (S), medium (M) and large (L) RNA segment of negative polarity. The

  12. Viral haemorrhagic fevers in South Africa

    African Journals Online (AJOL)

    transmission that occurs from contact of the virus with the face or neck, most ... of PPE or on inadvertently touching the face. In Africa, the HF viruses belong to one of three families, namely the Arenaviridae (Lassa and Lujo viruses), Bunyaviridae (Crimean- ... setting, and delay in recognition may have dire effects.[1] A small.

  13. Editorial: Identification and incidence of iris yellow spot virus, a new pathogen in onion and leek in Greece

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Giavachtsia, V.; Hassani-Mehraban, A.; Hoedjes, K.; Peters, D.

    2009-01-01

    Iris yellow spot virus (IYSV; genus Tospovirus, family Bunyaviridae) is an emerging and serious pathogen affecting several Allium spp. worldwide (2). The virus causes straw-colored, chlorotic or necrotic lesions that coalesce, occasionally resulting in an extensive necrosis on onion (A. cepa L.)

  14. Pathology Review of Two New Rift Valley Fever Virus Ruminant Models

    Science.gov (United States)

    Rift Valley fever virus (RVFV), is a mosquito-borne, zoonotic pathogen within genus Phlebovirus, family Bunyaviridae that typically causes outbreaks in sub-Saharan Africa and recently spread to the Arabian Peninsula. In ruminants, RVFV infections cause mass abortion and high mortality rates in neona...

  15. Wolbachia Effects on Rift Valley Virus Infection in Culex tarsalis Mosquitoes

    Science.gov (United States)

    2017-04-25

    invertebrates [7]. Infection by Wolbachia is not innocuous; its presence 77" within a host can cause broad effects on host physiology. For example...94" across several malaria species and virus families [20,22,24–27]. Thus, it is important to examine 95" the range of Wolbachia-induced phenotypes...genus Phlebovirus in the family Bunyaviridae 101" and is predominately a disease of domestic ruminants that causes severe economic losses in the 102

  16. Planning for Rift Valley fever virus: use of geographical information systems to estimate the human health threat of white-tailed deer (Odocoileus virginianus)-related transmission

    OpenAIRE

    Sravan Kakani; Desirée LaBeaud, A.; King, Charles H.

    2010-01-01

    Rift Valley fever (RVF) virus is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt and the Arabian Peninsula. Based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from East Africa to neighbouring regions, RVF is considered a high-priority, emerging health threat for humans, livestock and wildlife in all parts of the world. Int...

  17. Planning for Rift Valley fever virus: Use of GIS to estimate the human health threat of white-tailed deer (Odocoileus virginianus)-related transmission

    OpenAIRE

    Kakani, Sravan; LaBeaud, A. Desirée; King, Charles H.

    2010-01-01

    Rift Valley fever virus (RVFV) is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt,and the Arabian Peninsula. Based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from East Africa to neighboring regions, RVFV is considered a high-priority, emerging health threat forhumans, livestock, and wildlife in all parts of the world. In...

  18. Diffusion and Home Range Parameters for Rodents: Peromyscus maniculatus in New Mexico

    OpenAIRE

    Abramson, G.; Giuggioli, L.; Kenkre, V. M.; Dragoo, J. W.; Parmenter, R. R.; Parmenter, C. A.; Yates, T. L.

    2005-01-01

    We analyze data from a long term field project in New Mexico, consisting of repeated sessions of mark-recaptures of Peromyscus maniculatus (Rodentia: Muridae), the host and reservoir of Sin Nombre Virus (Bunyaviridae: Hantavirus). The displacements of the recaptured animals provide a means to study their movement from a statistical point of view. We extract two parameters from the data with the help of a simple model: the diffusion constant of the rodents, and the size of their home range. Th...

  19. Development of a microarray for simultaneous detection and differentiation of different tospoviruses that are serologically related to Tomato spotted wilt virus

    OpenAIRE

    Liu, Lu-Yuan; Ye, He-Yi; Chen, Tsang-Hai; Chen, Tsung-Chi

    2017-01-01

    Background Tospoviruses, the plant-infecting genus in the family Bunyaviridae, are thrips borne and cause severe agricultural losses worldwide. Based on the serological relationships of the structural nucleocapsid protein (NP), the current tospoviruses are divided into six serogroups. The use of NP-antisera is convenient for virus detection, but it is insufficient to identify virus species grouped in a serogroup due to the serological cross-reaction. Alternatively, virus species can be identi...

  20. Crimean-Congo haemorrhagic fever virus in Kazakhstan (1948-2013)

    OpenAIRE

    Nurmakhanov, Talgat; Sansyzbaev, Yerlan; Atshabar, Bakhyt; Deryabin, Pavel; Kazakov, Stanislav; Zholshorinov, Aitmagambet; Matzhanova, Almagul; Sadvakassova, Alya; Saylaubekuly, Ratbek; Kyraubaev, Kakimzhan; Hay, John; Atkinson, Barry; Hewson, Roger

    2015-01-01

    Crimean-Congo haemorrhagic fever (CCHF) is a pathogenic and often fatal arboviral disease with a distribution spanning large areas of Africa, Europe and Asia. The causative agent is a negative-sense single-stranded RNA virus classified within the Nairovirus genus of the Bunyaviridae family. Cases of CCHF have been officially recorded in Kazakhstan since the disease was first officially reported in modern medicine. Serological surveillance of human and animal populations provide evidence th...

  1. Emerging new poleroviruses and tospoviruses affecting vegetables in Asia and breeding for resistance

    OpenAIRE

    Relevante, C.; Cheewachaiwit, S.; Chuapong, J.; Stratongjun, M.; Salutan, V.E.; Peters, D.; Balatero, C.H.; Hoop, de, D.W.

    2012-01-01

    The diseases caused by aphid-borne poleroviruses (genus Polerovirus, family Luteoviridae) and thrips-borne tospoviruses (genus Tospovirus, family Bunyaviridae) are emerging threats to the production of economically important vegetable and fruit crops in tropical and sub-tropical Asia. To date, at least 13 different polerovirus species have been characterized. In Asia, the reported poleroviruses include Cucurbit aphid-borne yellows virus (CABYV), Melon aphid-borne yellows virus (MABYV) and Sua...

  2. Characterization of Bean Necrotic Mosaic Virus: A Member of a Novel Evolutionary Lineage within the Genus Tospovirus

    OpenAIRE

    Athos Silva de Oliveira; Fernando Lucas de Melo; Alice Kazuko Inoue-Nagata; Tatsuya Nagata; Elliot Watanabe Kitajima; Renato de Oliveira Resende

    2012-01-01

    BACKGROUND: Tospoviruses (Genus Tospovirus, Family Bunyaviridae) are phytopathogens responsible for significant worldwide crop losses. They have a tripartite negative and ambisense RNA genome segments, termed S (Small), M (Medium) and L (Large) RNA. The vector-transmission is mediated by thrips in a circulative-propagative manner. For new tospovirus species acceptance, several analyses are needed, e.g., the determination of the viral protein sequences for enlightenment of their evolutionary h...

  3. Temporal Dynamics of Iris Yellow Spot Virus and Its Vector, Thrips tabaci (Thysanoptera: Thripidae), in Seeded and Transplanted Onion Fields

    OpenAIRE

    Hsu, Cynthia L.; Hoepting, Christine A.; Fuchs, Marc; Shelton, Anthony M.; Nault, Brian A.

    2017-01-01

    Onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), can reduce onion bulb yield and transmit iris yellow spot virus (IYSV) (Bunyaviridae: Tospovirus), which can cause additional yield losses. In New York, onions are planted using seeds and imported transplants. IYSV is not seed transmitted, but infected transplants have been found in other U.S. states. Transplants are also larger than seeded onions early in the season, and thrips, some of which may be viruliferous, may preferent...

  4. Expression and Characterization of a Soluble Form of Tomato Spotted Wilt Virus Glycoprotein GN

    OpenAIRE

    Whitfield, Anna E.; Ullman, Diane E.; German, Thomas L

    2004-01-01

    Tomato spotted wilt virus (TSWV), a member of the Tospovirus genus within the Bunyaviridae, is an economically important plant pathogen with a worldwide distribution. TSWV is transmitted to plants via thrips (Thysanoptera: Thripidae), which transmit the virus in a persistent propagative manner. The envelope glycoproteins, GN and GC, are critical for the infection of thrips, but they are not required for the initial infection of plants. Thus, it is assumed that the envelope glycoproteins play ...

  5. Manual of Hemorrhagic Fever with Renal Syndrome

    Science.gov (United States)

    1989-04-01

    studies of antibody avidities in IAHA through the course of infection were carried out with rotavirus and togavirus systems (122), and the mechanism...IAHA buffer. a. Blood is collected from several candidate donors in volumes of 5 ml and the IAHA sensitivity is tested by box titration. The blood...syndrome as candidate members of the Bunyaviridae family. Arch Virol 78 : 137-144, 1983 50. Martin ML, Regnery HL, Sasso DR, McCormick JB, Palmer EL

  6. [Isolation of influenza virus A (Orthomyxoviridae, Influenza A virus), Dhori virus (Orthomyxoviridae, Thogotovirus), and Newcastle's disease virus (Paromyxoviridae, Avulavirus) on the Malyi Zhemchuzhnyi Island in the north-western area of the Caspian Sea].

    Science.gov (United States)

    Iashkulov, K B; Shchelkanov, M Iu; L'vov, S S; Dzhambinov, S D; Galkina, I V; Fediakina, I T; Bushkieva, B Ts; Morozova, T N; Kireev, D E; Akanina, D S; Litvin, K E; Usachev, E V; Prilipov, A G; Grebennikova, T V; Gromashevskiĭ, V L; Iamnikova, S S; Zaberezhnyĭ, A D; L'vov, D K

    2008-01-01

    The paper presents the results of the 2003 and 2006 environmental virological monitoring surveys on the Malyi Zhemchuzhnyi Island where a large breeding colony of sea gull (Laridae) is located. In the past several years, expansion of cormorants (Phalacrocorax carbo) has enhanced the intensity of populational interactions. The investigators isolated 13 strains of influenza A virus (Orthomyxoviridae, Influenza A virus) subtype H13N1 (from sea gulls (n = 4), cormorants (n = 9) 1 strain of Dhori virus (Orthomyxoviridae, Thogotovirus) from a cormorantwith clinical symptoms of the disease, 3 strains of Newcastle disease virus (Paramyxoviridae, Avulavirus) from cormorants. RT-PCR revealed influenza A virus subtype H5 in 3.1% of the cloacal lavages from cormorants. Neutralization test indicated that sera from cormorants contained specific antibodies against West Nile (Flaviviridae, Flavivirus) (15.0%), Sindbis (Togaviridae, Alphavirus) (5.0%), Dhori (10.0%), and Tahini (Bunyaviridae, Orthobunyavirus) (5.0%); sera from herring gulls had antibodies against Dhori virus (16.7%); there were no specific antibodies to Inco (Bunyaviridae, Orthobunyavirus) and mountain hare (Lepus timidus) (Bunyaviridae, Orthobunyavirus) virus.

  7. Bunyavirus-Vector Interactions

    Directory of Open Access Journals (Sweden)

    Kate McElroy Horne

    2014-11-01

    Full Text Available The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review presents an overview of several important emerging or re-emerging bunyaviruses and describes what is known about bunyavirus-vector interactions based on epidemiological, ultrastructural, and genetic studies of members of this virus family.

  8. Molecular evolution of Puumala hantavirus in Fennoscandia: phylogenetic analysis of strains from two recolonization routes

    DEFF Research Database (Denmark)

    Asikainen, Kari; Hänninen, Tarja; Henttonen, Heikki

    2000-01-01

    Like other members of the genus Hantavirus in the family Bunyaviridae, Puumala virus (PUUV) is thought to be co-evolving with its natural host, the bank vole Clethrionomys glareolus. To gain insight into the evolutionary history of PUUV in northern Europe during the last post-glacial period, we...... relatedness to any of the known PUUV strains and formed a distinct phylogenetic lineage on trees calculated for both S and M segment sequences. Although no direct link between the Danish PUUV strains and those of the southern Scandinavian lineage was found, within the S segment of Danish PUUV strains, two...

  9. Arbovirosis y operación ATALANTA: riesgo para viajeros y medidas de prevención y control

    OpenAIRE

    JF. Plaza Torres; R. Navarro Suay

    2014-01-01

    El término arbovirosis se utiliza para definir a un grupo de enfermedades producidas por virus, que tiene en común la utilización de artrópodos como vectores para su transmisión. Se han reconocido más de 500 arbovirus pertenecientes en su mayoría a 5 familias: Flaviviridae, Togaviridae, Bunyaviridae, Reoviridae y Rhabdoviridae. Pese a su naturaleza mayoritariamente zoonótica, al menos un 25% de ellas afectan al hombre, siendo responsables de enfermedades como la fiebre amarilla, dengue o la f...

  10. The NSs protein of tomato spotted wilt virus is required for persistent infection and transmission by Frankliniella occidentalis.

    Science.gov (United States)

    Margaria, P; Bosco, L; Vallino, M; Ciuffo, M; Mautino, G C; Tavella, L; Turina, M

    2014-05-01

    Tomato spotted wilt virus (TSWV) is the type member of tospoviruses (genus Tospovirus), plant-infecting viruses that cause severe damage to ornamental and vegetable crops. Tospoviruses are transmitted by thrips in the circulative propagative mode. We generated a collection of NSs-defective TSWV isolates and showed that TSWV coding for truncated NSs protein could not be transmitted by Frankliniella occidentalis. Quantitative reverse transcription (RT)-PCR and immunostaining of individual insects detected the mutant virus in second-instar larvae and adult insects, demonstrating that insects could acquire and accumulate the NSs-defective virus. Nevertheless, adults carried a significantly lower viral load, resulting in the absence of transmission. Genome sequencing and analyses of reassortant isolates showed genetic evidence of the association between the loss of competence in transmission and the mutation in the NSs coding sequence. Our findings offer new insight into the TSWV-thrips interaction and Tospovirus pathogenesis and highlight, for the first time in the Bunyaviridae family, a major role for the S segment, and specifically for the NSs protein, in virulence and efficient infection in insect vector individuals. Our work is the first to show a role for the NSs protein in virus accumulation in the insect vector in the Bunyaviridae family: demonstration was obtained for the system TSWV-F. occidentalis, arguably one of the most damaging combination for vegetable crops. Genetic evidence of the involvement of the NSs protein in vector transmission was provided with multiple approaches.

  11. Interaction of Tomato Spotted Wilt Tospovirus (TSWV) Glycoproteins with a Thrips Midgut Protein, a Potential Cellular Receptor for TSWV.

    Science.gov (United States)

    Bandla, M D; Campbell, L R; Ullman, D E; Sherwood, J L

    1998-02-01

    ABSTRACT Interactions between viral and cellular membrane fusion proteins mediate virus penetration of cells for many arthropod-borne viruses. Electron microscope observations and circumstantial evidence indicate insect acquisition of tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) is receptor mediated, and TSWV membrane glycoproteins (GP1 and GP2) serve as virus attachment proteins. The tospoviruses are plant-infecting members of the family Bunyaviridae and are transmitted by several thrips species, including Frankliniella occidentalis. Gel overlay assays and immunolabeling were used to investigate the putative role of TSWV GPs as viral attachment proteins and deter mine whether a corresponding cellular receptor may be present in F. occidentalis. A single band in the 50-kDa region was detected with murine monoclonal antibodies (MAbs) to the TSWV-GPs when isolated TSWV or TSWV-GPs were used to overlay separated thrips proteins. This band was not detected when blots were probed with antibody to the non-structural protein encoded by the small RNA of TSWV or the TSWV nucleocapsid protein, nor were proteins from nonvector insects labeled. Anti-idiotype antibodies prepared to murine MAbs against GP1 or GP2 specifically labeled a single band at 50 kDa in Western blots and the plasmalemma of larval thrips midguts. These results support the putative role of the TSWV GPs as viral attachment proteins and identified potential cellular receptor(s) in thrips.

  12. Tick-borne viruses: a review from the perspective of therapeutic approaches.

    Science.gov (United States)

    Lani, Rafidah; Moghaddam, Ehsan; Haghani, Amin; Chang, Li-Yen; AbuBakar, Sazaly; Zandi, Keivan

    2014-09-01

    Several important human diseases worldwide are caused by tick-borne viruses. These diseases have become important public health concerns in recent years. The tick-borne viruses that cause diseases in humans mainly belong to 3 families: Bunyaviridae, Flaviviridae, and Reoviridae. In this review, we focus on therapeutic approaches for several of the more important tick-borne viruses from these 3 families. These viruses are Crimean-Congo hemorrhagic fever virus (CCHF) and the newly discovered tick-borne phleboviruses, known as thrombocytopenia syndromevirus (SFTSV), Heartland virus and Bhanja virus from the family Bunyaviridae, tick-borne encephalitis virus (TBEV), Powassan virus (POWV), Louping-ill virus (LIV), Omsk hemorrhagic fever virus (OHFV), Kyasanur Forest disease virus (KFDV), and Alkhurma hemorrhagic fever virus (AHFV) from the Flaviviridae family. To date, there is no effective antiviral drug available against most of these tick-borne viruses. Although there is common usage of antiviral drugs such as ribavirin for CCHF treatment in some countries, there are concerns that ribavirin may not be as effective as once thought against CCHF. Herein, we discuss also the availability of vaccines for the control of these viral infections. The lack of treatment and prevention approaches for these viruses is highlighted, and we hope that this review may increase public health awareness with regard to the threat posed by this group of viruses. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Characterization of Botrytis cinerea negative-stranded RNA virus 1, a new mycovirus related to plant viruses, and a reconstruction of host pattern evolution in negative-sense ssRNA viruses.

    Science.gov (United States)

    Donaire, Livia; Pagán, Israel; Ayllón, María A

    2016-12-01

    The molecular characterization of a novel negative single-stranded RNA virus infecting the plant pathogenic fungus Botrytis cinerea is reported here. Comparison of the sequence of Botrytis cinerea negative-stranded RNA virus 1 (BcNSRV-1) showed a strong identity with RNA dependent RNA polymerases (RdRps) of plant pathogenic emaraviruses and tospoviruses. We have also found all the molecular signatures present in the RdRp of the genus Emaravirus and in other genera of family Bunyaviridae: the conserved TPD triplet and RY dinucleotide, the three basic residues in premotif A and the conserved motifs A, B, C, D, and E. Our results showed that BcNSRV-1 is phylogenetically close to members of the genus Emaravirus and of the family Bunyaviridae, and an ancestral state reconstruction using the conserved RdRp motifs of type members of each family of (-)ssRNA viruses indicated that BcNSRV-1 could possibly derive from an invertebrate and vertebrate-infecting virus. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. RNA Encapsidation and Packaging in the Phleboviruses

    Directory of Open Access Journals (Sweden)

    Katherine E. Hornak

    2016-07-01

    Full Text Available The Bunyaviridae represents the largest family of segmented RNA viruses, which infect a staggering diversity of plants, animals, and insects. Within the family Bunyaviridae, the Phlebovirus genus includes several important human and animal pathogens, including Rift Valley fever virus (RVFV, severe fever with thrombocytopenia syndrome virus (SFTSV, Uukuniemi virus (UUKV, and the sandfly fever viruses. The phleboviruses have small tripartite RNA genomes that encode a repertoire of 5–7 proteins. These few proteins accomplish the daunting task of recognizing and specifically packaging a tri-segment complement of viral genomic RNA in the midst of an abundance of host components. The critical nucleation events that eventually lead to virion production begin early on in the host cytoplasm as the first strands of nascent viral RNA (vRNA are synthesized. The interaction between the vRNA and the viral nucleocapsid (N protein effectively protects and masks the RNA from the host, and also forms the ribonucleoprotein (RNP architecture that mediates downstream interactions and drives virion formation. Although the mechanism by which all three genomic counterparts are selectively co-packaged is not completely understood, we are beginning to understand the hierarchy of interactions that begins with N-RNA packaging and culminates in RNP packaging into new virus particles. In this review we focus on recent progress that highlights the molecular basis of RNA genome packaging in the phleboviruses.

  15. Rice Stripe Tenuivirus NSvc2 Glycoproteins Targeted to the Golgi Body by the N-Terminal Transmembrane Domain and Adjacent Cytosolic 24 Amino Acids via the COP I- and COP II-Dependent Secretion Pathway

    Science.gov (United States)

    Yao, Min; Liu, Xiaofan; Li, Shuo; Xu, Yi; Zhou, Yijun

    2014-01-01

    ABSTRACT The NSvc2 glycoproteins encoded by Rice stripe tenuivirus (RSV) share many characteristics common to the glycoproteins found among Bunyaviridae. Within this viral family, glycoproteins targeting to the Golgi apparatus play a pivotal role in the maturation of the enveloped spherical particles. RSV particles, however, adopt a long filamentous morphology. Recently, RSV NSvc2 glycoproteins were shown to localize exclusively to the ER in Sf9 insect cells. Here, we demonstrate that the amino-terminal NSvc2 (NSvc2-N) targets to the Golgi apparatus in Nicotiana benthamiana cells, whereas the carboxyl-terminal NSvc2 (NSvc2-C) accumulates in the endoplasmic reticulum (ER). Upon coexpression, NSvc2-N redirects NSvc2-C from the ER to the Golgi bodies. The NSvc2 glycoproteins move together with the Golgi stacks along the ER/actin network. The targeting of the NSvc2 glycoproteins to the Golgi bodies was strictly dependent on functional anterograde traffic out of the ER to the Golgi bodies or on a retrograde transport route from the Golgi apparatus. The analysis of truncated and chimeric NSvc2 proteins demonstrates that the Golgi targeting signal comprises amino acids 269 to 315 of NSvc2-N, encompassing the transmembrane domain and 24 adjacent amino acids in the cytosolic tail. Our findings demonstrate for the first time that the glycoproteins from an unenveloped Tenuivirus could target Golgi bodies in plant cells. IMPORTANCE NSvc2 glycoprotein encoded by unenveloped Rice stripe tenuivirus (RSV) share many characteristics in common with glycoprotein found among Bunyaviridae in which all members have membrane-enveloped sphere particle. Recently, RSV NSvc2 glycoproteins were shown to localize exclusively to the ER in Sf9 insect cells. In this study, we demonstrated that the RSV glycoproteins could target Golgi bodies in plant cells. The targeting of NSvc2 glycoproteins to the Golgi bodies was dependent on active COP II or COP I. The Golgi targeting signal was mapped to the

  16. Insect-Specific Viruses: A Historical Overview and Recent Developments.

    Science.gov (United States)

    Roundy, Christopher M; Azar, Sasha R; Rossi, Shannan L; Weaver, Scott C; Vasilakis, Nikos

    2017-01-01

    Arthropod-borne viruses (arboviruses) have in recent years become a tremendous global health concern resulting in substantial human morbidity and mortality. With the widespread utilization of molecular technologies such as next-generation sequencing and the advancement of bioinformatics tools, a new age of viral discovery has commenced. Many of the novel agents being discovered in recent years have been isolated from mosquitoes and exhibit a highly restricted host range. Strikingly, these insect-specific viruses have been found to be members of viral families traditionally associated with human arboviral pathogens, including but not limited to the families Flaviviridae, Togaviridae, Reoviridae, and Bunyaviridae. These agents therefore present novel opportunities in the fields of viral evolution and viral/vector interaction and have tremendous potential as agents for biocontrol of vectors and or viruses of medical importance. © 2017 Elsevier Inc. All rights reserved.

  17. Sequence analysis of the medium RNA segment of three Simbu serogroup viruses, Akabane, Aino, and Peaton viruses.

    Science.gov (United States)

    Yanase, Tohru; Yoshida, Kazuo; Ohashi, Seiichi; Kato, Tomoko; Tsuda, Tomoyuki

    2003-05-01

    The sequence analysis was carried out for the medium (M) RNA segment of the Akabane virus (AKAV), Aino virus (AINV), and Peaton virus (PEAV) of the Simbu serogroup of the genus Orthobunyavirus of the family Bunyaviridae. The complementary sequences of the M RNA segments of AKAV, AINV, and PEAV contain a single large open reading frame (ORF), like other orthobunyaviruses. The ORFs potentially encode 1401 amino acids (aa), 1404 aa, and 1400 aa polypeptides, respectively. The identity of the M segment among these viruses is remarkably low, although previous researchers reported that the small RNA segments are highly conserved. Because the M segment codes for the viral surface glycoproteins G1 and G2, the variability of the M segment may affect the antigenicity of these viruses. Phylogenetic studies based on the M and S segment sequences suggested that genetic reassortment has been occurring among ancestral viruses of the three Simbu serogroup viruses throughout their evolution.

  18. Detection of Orthobunyavirus in mosquitoes collected in Argentina.

    Science.gov (United States)

    Tauro, L B; Batallan, G P; Rivarola, M E; Visintin, A; Berrón, C I; Sousa, E C; Diaz, L A; Almiron, W R; Nunes, M R; Contigiani, M S

    2015-09-01

    Bunyamwera virus (BUNV) (Bunyaviridae, genus Orthobunyavirus, serogroup Bunyamwera) is considered an emerging pathogen for humans and animals in American countries. The CbaAr-426 strain of BUNV was recovered from mosquitoes Ochlerotatus albifasciatus (Diptera: Culicidae) collected in Córdoba province (Argentina), where serological studies detected high seroprevalences in humans and animals. Molecular detection of Orthobunyavirus was performed in mosquitoes collected in Córdoba province. Seventeen mosquito pools of Oc. albifasciatus, Ochlerotatus scapularis and Culex quinquefasciatus (Diptera: Culicidae) showed positive results; four of these positive pools, all of Oc. scapularis, were sequenced. All amplicons grouped with BUNV in the Bunyamwera serogroup. The findings highlight the circulation of BUNV in Córdoba province and represent the first report of BUNV-infected Oc. scapularis mosquitoes in Argentina. © 2015 The Royal Entomological Society.

  19. Isolation of Kaeng Khoi virus from dead Chaerephon plicata bats in Cambodia.

    Science.gov (United States)

    Osborne, J C; Rupprecht, C E; Olson, J G; Ksiazek, T G; Rollin, P E; Niezgoda, M; Goldsmith, C S; An, U S; Nichol, S T

    2003-10-01

    A virus isolated from dead Chaerephon plicata bats collected near Kampot, Cambodia, was identified as a member of the family Bunyaviridae by electron microscopy. The only bunyavirus previously isolated from Chaerephon species bats in South-East Asia is Kaeng Khoi (KK) virus (genus Orthobunyavirus), detected in Thailand over 30 years earlier and implicated as a public health problem. Using RT-PCR, nucleotide sequences from the M RNA segment of several virus isolates from the Cambodian C. plicata bats were found to be almost identical and to differ from those of the prototype KK virus by only 2.6-3.2 %, despite the temporal and geographic separation of the viruses. These results identify the Cambodian bat viruses as KK virus, extend the known virus geographic range and document the first KK virus isolation in 30 years. These genetic data, together with earlier serologic data, show that KK viruses represent a distinct group within the genus Orthobunyavirus.

  20. Schmallenberg virus infection of ruminants: challenges and opportunities for veterinarians

    Directory of Open Access Journals (Sweden)

    Claine F

    2015-06-01

    Full Text Available François Claine, Damien Coupeau, Laetitia Wiggers, Benoît Muylkens, Nathalie Kirschvink Veterinary Department, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS, University of Namur (UNamur, Namur, Belgium Abstract: In 2011, European ruminant flocks were infected by Schmallenberg virus (SBV leading to transient disease in adult cattle but abortions and congenital deformities in calves, lambs, and goat kids. SBV belonging to the Simbu serogroup (family Bunyaviridae and genus Orthobunyavirus was first discovered in the same region where bluetongue virus serotype 8 (BTV-8 emerged 5 years before. Both viruses are transmitted by biting midges (Culicoides spp. and share several similarities. This paper describes the current knowledge of temporal and geographical spread, molecular virology, transmission and susceptible species, clinical signs, diagnosis, prevention and control, impact on ruminant health, and productivity of SBV infection in Europe, and compares SBV infection with BTV-8 infection in ruminants. Keywords: Schmallenberg virus, Europe, ruminants, review

  1. The major cellular sterol regulatory pathway is required for Andes virus infection.

    Directory of Open Access Journals (Sweden)

    Josiah Petersen

    2014-02-01

    Full Text Available The Bunyaviridae comprise a large family of RNA viruses with worldwide distribution and includes the pathogenic New World hantavirus, Andes virus (ANDV. Host factors needed for hantavirus entry remain largely enigmatic and therapeutics are unavailable. To identify cellular requirements for ANDV infection, we performed two parallel genetic screens. Analysis of a large library of insertionally mutagenized human haploid cells and a siRNA genomic screen converged on components (SREBP-2, SCAP, S1P and S2P of the sterol regulatory pathway as critically important for infection by ANDV. The significance of this pathway was confirmed using functionally deficient cells, TALEN-mediated gene disruption, RNA interference and pharmacologic inhibition. Disruption of sterol regulatory complex function impaired ANDV internalization without affecting virus binding. Pharmacologic manipulation of cholesterol levels demonstrated that ANDV entry is sensitive to changes in cellular cholesterol and raises the possibility that clinically approved regulators of sterol synthesis may prove useful for combating ANDV infection.

  2. Crimean-Congo hemorrhagic fever in Tajikistan.

    Science.gov (United States)

    Tishkova, Farida H; Belobrova, Evgeniya A; Valikhodzhaeva, Matlyuba; Atkinson, Barry; Hewson, Roger; Mullojonova, Manija

    2012-09-01

    Crimean-Congo hemorrhagic fever (CCHF) is a pathogenic tick-borne disease caused by a single-stranded negative-sense RNA virus classified within the Nairovirus genus of the family Bunyaviridae. Cases of CCHF have been registered in Tajikistan since the disease was first brought to medical attention in 1944. However, historical Tajik manuscripts describe the features of hemorrhagic fever associated with ticks, indicating that the disease might have been known in this region for many years before it was officially characterized. Here we review the historical context of CCHF in Tajikistan, much of which has been described over several decades in the Russian literature, and include reports of recent outbreaks in Tajikistan.

  3. Evidence of segment reassortment in Crimean-Congo haemorrhagic fever virus.

    Science.gov (United States)

    Hewson, Roger; Gmyl, Anatoly; Gmyl, Larissa; Smirnova, Svetlana E; Karganova, Galina; Jamil, Bushra; Hasan, Rumina; Chamberlain, John; Clegg, Christopher

    2004-10-01

    The complete nucleotide sequences of the small (S) and medium (M) segments of three independent strains of Crimean-Congo haemorrhagic fever (CCHF) virus isolated in Uzbekistan, Iraq and Pakistan have been determined. Partial S and M segment sequences from two additional strains and partial large segment sequences from five strains of CCHF virus have also been obtained. These data have been compiled and compared with published full-length and partial sequences of other CCHF virus strains. Analysis of virus strains for which complete and partial S and M segment sequences are available reveals that the phylogenetic grouping of some strains differ between these two segments. Data provided in this report suggest that this discrepancy is not the result of recombination, but rather the consequence of reassortment events that have occurred in some virus lineages. Although described in other genera of the Bunyaviridae family, this is the first report of segment reassortment occurring in the Nairovirus genus.

  4. Co-evolutionary patterns of variation in small and large RNA segments of Crimean-Congo hemorrhagic fever virus.

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    Chamberlain, John; Cook, Nicola; Lloyd, Graham; Mioulet, Valerie; Tolley, Howard; Hewson, Roger

    2005-12-01

    The genus Nairovirus of the family Bunyaviridae includes the Crimean-Congo haemorrhagic fever (CCHF) species group. The species is predominated by the hazard-group 4 pathogens, from which the name and majority of strain entries are derived. Additionally, the species embraces hazard-group 2 viruses that are classified as members by antigenic cross-reactivity. CCHF viruses have a tripartite RNA genome consisting of large (L), medium (M) and small (S) segments. Here, the sequence characterization of previously undescribed L and S segments from novel strains originating in the Middle East and Africa is reported. Further scrutiny of this data with phylogenetic tools, in the context of other publicly available sequence information, reveals analogous grouping patterns between the L and S segments. These groups correlate with the geographical distribution of strain isolation and indicate that the L and S segments of CCHF viruses have evolved together.

  5. The Genus Tospovirus: Emerging Bunyaviruses that Threaten Food Security.

    Science.gov (United States)

    Oliver, J E; Whitfield, A E

    2016-09-29

    The genus Tospovirus is unique within the family Bunyaviridae in that it is made up of viruses that infect plants. Initially documented over 100 years ago, tospoviruses have become increasingly important worldwide since the 1980s due to the spread of the important insect vector Frankliniella occidentalis and the discovery of new viruses. As a result, tospoviruses are now recognized globally as emerging agricultural diseases. Tospoviruses and their vectors, thrips species in the order Thysanoptera, represent a major problem for agricultural and ornamental crops that must be managed to avoid devastating losses. In recent years, the number of recognized species in the genus has increased rapidly, and our knowledge of the molecular interactions of tospoviruses with their host plants and vectors has expanded. In this review, we present an overview of the genus Tospovirus with particular emphasis on new understandings of the molecular plant-virus and vector-virus interactions as well as relationships among genus members.

  6. Comparative phylogenetic analysis of Dobrava-Belgrade virus L and S genetic segments isolated from an animal reservoir in Serbia

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    Nikolić Valentina

    2014-01-01

    Full Text Available The Dobrava-Belgrade virus (DOBV is a member of the Bunyaviridae family, genus Hantavirus, possessing a single-stranded RNA genome consisting of three segments, designated L (large, M (medium and S (small. In this study, we present phylogenetic analysis of a newly detected DOBV strain isolated from Apodemus agrarius. Analysis was based on partial L and S segment sequences, in comparison to previously published DOBV sequences from Serbia and elsewhere. A phylogenetic tree based on partial S segment revealed local geographical clustering of DOBV sequences from Serbia, unrelated to host (rodent or human. The topology of the phylogenetic tree was confirmed with a high percent of completely or partially resolved quartets in likelihood-mapping analysis, whereas no evidence of possible recombination in the examined S segment data set was found.

  7. An update on crimean congo hemorrhagic fever

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    Suma B Appannanavar

    2011-01-01

    Full Text Available Crimean Congo hemorrhagic fever (CCHF is one of the deadly hemorrhagic fevers that are endemic in Africa, Asia, Eastern Europe, and the Middle East. It is a tick-borne zoonotic viral disease caused by CCHF virus of genus Nairovirus (family Bunyaviridae. CCHF not only forms an important public health threat but has a significant effect on the healthcare personnel, especially in resource-poor countries. India was always a potentially endemic area until an outbreak hit parts of Gujarat, taking four lives including the treating medical team. The current review is an attempt to summarize the updated knowledge on the disease particularly in modern era, with special emphasis on nosocomial infections. The knowledge about the disease may help answer certain questions regarding entry of virus in India and future threat to community.

  8. Searching for cellular partners of hantaviral nonstructural protein NSs: Y2H screening of mouse cDNA library and analysis of cellular interactome.

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    Tuomas Rönnberg

    Full Text Available Hantaviruses (Bunyaviridae are negative-strand RNA viruses with a tripartite genome. The small (S segment encodes the nucleocapsid protein and, in some hantaviruses, also the nonstructural protein (NSs. The aim of this study was to find potential cellular partners for the hantaviral NSs protein. Toward this aim, yeast two-hybrid (Y2H screening of mouse cDNA library was performed followed by a search for potential NSs protein counterparts via analyzing a cellular interactome. The resulting interaction network was shown to form logical, clustered structures. Furthermore, several potential binding partners for the NSs protein, for instance ACBD3, were identified and, to prove the principle, interaction between NSs and ACBD3 proteins was demonstrated biochemically.

  9. The major cellular sterol regulatory pathway is required for Andes virus infection.

    Science.gov (United States)

    Petersen, Josiah; Drake, Mary Jane; Bruce, Emily A; Riblett, Amber M; Didigu, Chukwuka A; Wilen, Craig B; Malani, Nirav; Male, Frances; Lee, Fang-Hua; Bushman, Frederic D; Cherry, Sara; Doms, Robert W; Bates, Paul; Briley, Kenneth

    2014-02-01

    The Bunyaviridae comprise a large family of RNA viruses with worldwide distribution and includes the pathogenic New World hantavirus, Andes virus (ANDV). Host factors needed for hantavirus entry remain largely enigmatic and therapeutics are unavailable. To identify cellular requirements for ANDV infection, we performed two parallel genetic screens. Analysis of a large library of insertionally mutagenized human haploid cells and a siRNA genomic screen converged on components (SREBP-2, SCAP, S1P and S2P) of the sterol regulatory pathway as critically important for infection by ANDV. The significance of this pathway was confirmed using functionally deficient cells, TALEN-mediated gene disruption, RNA interference and pharmacologic inhibition. Disruption of sterol regulatory complex function impaired ANDV internalization without affecting virus binding. Pharmacologic manipulation of cholesterol levels demonstrated that ANDV entry is sensitive to changes in cellular cholesterol and raises the possibility that clinically approved regulators of sterol synthesis may prove useful for combating ANDV infection.

  10. Synthesis of bunyavirus-specific proteins in a continuous cell line (XTC-2) derived from Xenopus laevis.

    Science.gov (United States)

    Watret, G E; Pringle, C R; Elliott, R M

    1985-03-01

    The XTC-2 cell line, derived from Xenopus laevis, supported the replication of representative viruses from each of the four genera in the family Bunyaviridae. Generally, viral titres were higher in XTC-2 cells than in other susceptible cell lines, and for some viruses plaques were detected earlier in XTC-2 cells. The XTC-2 cell line permitted comparative analyses of bunyavirus-specific protein synthesis. The patterns of synthesis of viral proteins, characteristic of each of the genera, were observed with representative viruses. These studies provided biochemical characterization of two Scottish isolates, which support the inclusion of Clo Mor virus in the Nairovirus genus and St Abb's Head (M349) virus in the Uukuvirus genus.

  11. Non-Structural Proteins of Arthropod-Borne Bunyaviruses: Roles and Functions

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    Alain Kohl

    2013-10-01

    Full Text Available Viruses within the Bunyaviridae family are tri-segmented, negative-stranded RNA viruses. The family includes several emerging and re-emerging viruses of humans, animals and plants, such as Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, La Crosse virus, Schmallenberg virus and tomato spotted wilt virus. Many bunyaviruses are arthropod-borne, so-called arboviruses. Depending on the genus, bunyaviruses encode, in addition to the RNA-dependent RNA polymerase and the different structural proteins, one or several non-structural proteins. These non-structural proteins are not always essential for virus growth and replication but can play an important role in viral pathogenesis through their interaction with the host innate immune system. In this review, we will summarize current knowledge and understanding of insect-borne bunyavirus non-structural protein function(s in vertebrate, plant and arthropod.

  12. Molecular Assay on Crimean Congo Hemorrhagic Fever Virus in Ticks (Ixodidae) Collected from Kermanshah Province, Western Iran.

    Science.gov (United States)

    Mohammadian, Maria; Chinikar, Sadegh; Telmadarraiy, Zakkyeh; Vatandoost, Hassan; Oshaghi, Mohammad Ali; Hanafi-Bojd, Ahmad Ali; Sedaghat, Mohammad Mehdi; Noroozi, Mehdi; Faghihi, Faezeh; Jalali, Tahmineh; Khakifirouz, Sahar; Shahhosseini, Nariman; Farhadpour, Firoozeh

    2016-09-01

    Crimean-Congo Hemorrhagic Fever (CCHF) is a feverous and hemorrhagic disease endemic in some parts of Iran and caused by an arbovirus related to Bunyaviridae family and Nairovirusgenus. The main virus reservoir in the nature is ticks, however small vertebrates and a wide range of domestic and wild animals are regarded as reservoir hosts. This study was conducted to determine the infection rate of CCHF virus in hard ticks of Sarpole-Zahab County, Kermanshah province, west of Iran. From total number of 851 collected ticks from 8 villages, 131 ticks were selected randomlyand investigated for detection of CCHF virus using RT-PCR. The virus was found in 3.8% of the tested ticks. Hyalommaanatolicum, H. asiaticum and Rhipicephalus sanguineus species were found to have viral infection, with the highest infection rate (11.11%) in Rh. sanguineus. These findings provide epidemiological evidence for planning control strategies of the disease in the study area.

  13. Transmission of Iris yellow spot virus by Frankliniella fusca and Thrips tabaci (Thysanoptera: Thripidae).

    Science.gov (United States)

    Srinivasan, Rajagopalbabu; Sundaraj, Sivamani; Pappu, Hanu R; Diffie, Stan; Riley, David G; Gitaitis, Ron D

    2012-02-01

    Thrips-transmitted Iris yellow spot virus (IYSV) (Family Bunyaviridae, Genus Tospovirus) affects onion production in the United States and worldwide. The presence of IYSV in Georgia was confirmed in 2003. Two important thrips species that transmit tospoviruses, the onion thrips (Thrips tabaci (Lindeman)) and the tobacco thrips (Frankliniella fusca (Hinds)) are known to infest onion in Georgia. However, T. tabaci is the only confirmed vector of IYSV. Experiments were conducted to test the vector status of F. fusca in comparison with T. tabaci. F. fusca and T. tabaci larvae and adults reared on IYSV-infected hosts were tested with antiserum specific to the nonstructural protein of IYSV through an antigen coated plate ELISA. The detection rates for F. fusca larvae and adults were 4.5 and 5.1%, respectively, and for T. tabaci larvae and adults they were 20.0 and 24.0%, respectively, indicating that both F. fusca and T. tabaci can transmit IYSV. Further, transmission efficiencies of F. fusca and T. tabaci were evaluated by using an indicator host, lisianthus (Eustoma russellianum (Salisbury)). Both F. fusca and T. tabaci transmitted IYSV at 18.3 and 76.6%, respectively. Results confirmed that F. fusca also can transmit IYSV but at a lower efficiency than T. tabaci. To attest if low vector competency of our laboratory-reared F. fusca population affected its IYSV transmission capability, a Tomato spotted wilt virus (Family Bunyaviridae, Genus Tospovirus) transmission experiment was conducted. F. fusca transmitted Tomato spotted wilt virus at a competent rate (90%) suggesting that the transmission efficiency of a competent thrips vector can widely vary between two closely related viruses.

  14. Multi-gene detection and identification of mosquito-borne RNA viruses using an oligonucleotide microarray.

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    Nathan D Grubaugh

    Full Text Available BACKGROUND: Arthropod-borne viruses are important emerging pathogens world-wide. Viruses transmitted by mosquitoes, such as dengue, yellow fever, and Japanese encephalitis viruses, infect hundreds of millions of people and animals each year. Global surveillance of these viruses in mosquito vectors using molecular based assays is critical for prevention and control of the associated diseases. Here, we report an oligonucleotide DNA microarray design, termed ArboChip5.1, for multi-gene detection and identification of mosquito-borne RNA viruses from the genera Flavivirus (family Flaviviridae, Alphavirus (Togaviridae, Orthobunyavirus (Bunyaviridae, and Phlebovirus (Bunyaviridae. METHODOLOGY/PRINCIPAL FINDINGS: The assay utilizes targeted PCR amplification of three genes from each virus genus for electrochemical detection on a portable, field-tested microarray platform. Fifty-two viruses propagated in cell-culture were used to evaluate the specificity of the PCR primer sets and the ArboChip5.1 microarray capture probes. The microarray detected all of the tested viruses and differentiated between many closely related viruses such as members of the dengue, Japanese encephalitis, and Semliki Forest virus clades. Laboratory infected mosquitoes were used to simulate field samples and to determine the limits of detection. Additionally, we identified dengue virus type 3, Japanese encephalitis virus, Tembusu virus, Culex flavivirus, and a Quang Binh-like virus from mosquitoes collected in Thailand in 2011 and 2012. CONCLUSIONS/SIGNIFICANCE: We demonstrated that the described assay can be utilized in a comprehensive field surveillance program by the broad-range amplification and specific identification of arboviruses from infected mosquitoes. Furthermore, the microarray platform can be deployed in the field and viral RNA extraction to data analysis can occur in as little as 12 h. The information derived from the ArboChip5.1 microarray can help to establish

  15. Characterization of the genome of a phylogenetically distinct tospovirus and its interactions with the local lesion-induced host Chenopodium quinoa by whole-transcriptome analyses.

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    Wan-Chen Chou

    Full Text Available Chenopodium quinoa is a natural local lesion host of numerous plant viruses, including tospoviruses (family Bunyaviridae. Groundnut chlorotic fan-spot tospovirus (GCFSV has been shown to consistently induce local lesions on the leaves of C. quinoa 4 days post-inoculation (dpi. To reveal the whole genome of GCFSV and its interactions with C. quinoa, RNA-seq was performed to determine the transcriptome profiles of C. quinoa leaves. The high-throughput reads from infected C. quinoa leaves were used to identify the whole genome sequence of GCFSV and its single nucleotide polymorphisms. Our results indicated that GCFSV is a phylogenetically distinct tospovirus. Moreover, 27,170 coding and 29,563 non-coding sequences of C. quinoa were identified through de novo assembly, mixing reads from mock and infected samples. Several key genes involved in the modulation of hypersensitive response (HR were identified. The expression levels of 4,893 deduced complete genes annotated using the Arabidopsis genome indicated that several HR-related orthologues of pathogenesis-related proteins, transcription factors, mitogen-activated protein kinases, and defense proteins were significantly expressed in leaves that formed local lesions. Here, we also provide new insights into the replication progression of a tospovirus and the molecular regulation of the C. quinoa response to virus infection.

  16. NSs encoded by groundnut bud necrosis virus is a bifunctional enzyme.

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    Bhushan Lokesh

    Full Text Available Groundnut bud necrosis virus (GBNV, a member of genus Tospovirus in the family Bunyaviridae, infects a large number of leguminosae and solanaceae plants in India. With a view to elucidate the function of nonstructural protein, NSs encoded by the small RNA genome (S RNA, the NSs protein of GBNV- tomato (Karnataka was over-expressed in E. coli and purified by Ni-NTA chromatography. The purified rNSs protein exhibited an RNA stimulated NTPase activity. Further, this activity was metal ion dependent and was inhibited by adenosine 5' (beta, gamma imido triphosphate, an ATP analog. The rNSs could also hydrolyze dATP. Interestingly, in addition to the NTPase and dATPase activities, the rNSs exhibited ATP independent 5' RNA/DNA phosphatase activity that was completely inhibited by AMP. The 5' alpha phosphate could be removed from ssDNA, ssRNA, dsDNA and dsRNA thus confirming that rNSs has a novel 5' alpha phosphatase activity. K189A mutation in the Walker motif A (GxxxxGKT resulted in complete loss of ATPase activity, but the 5' phosphatase activity was unaffected. On the other hand, D159A mutation in the Walker motif B (DExx resulted in partial loss of both the activities. These results demonstrate for the first time that NSs is a bifunctional enzyme, which could participate in viral movement, replication or in suppression of the host defense mechanism.

  17. Characterization of the genome of a phylogenetically distinct tospovirus and its interactions with the local lesion-induced host Chenopodium quinoa by whole-transcriptome analyses.

    Science.gov (United States)

    Chou, Wan-Chen; Lin, Shih-Shun; Yeh, Shyi-Dong; Li, Siang-Ling; Peng, Ying-Che; Fan, Ya-Hsu; Chen, Tsung-Chi

    2017-01-01

    Chenopodium quinoa is a natural local lesion host of numerous plant viruses, including tospoviruses (family Bunyaviridae). Groundnut chlorotic fan-spot tospovirus (GCFSV) has been shown to consistently induce local lesions on the leaves of C. quinoa 4 days post-inoculation (dpi). To reveal the whole genome of GCFSV and its interactions with C. quinoa, RNA-seq was performed to determine the transcriptome profiles of C. quinoa leaves. The high-throughput reads from infected C. quinoa leaves were used to identify the whole genome sequence of GCFSV and its single nucleotide polymorphisms. Our results indicated that GCFSV is a phylogenetically distinct tospovirus. Moreover, 27,170 coding and 29,563 non-coding sequences of C. quinoa were identified through de novo assembly, mixing reads from mock and infected samples. Several key genes involved in the modulation of hypersensitive response (HR) were identified. The expression levels of 4,893 deduced complete genes annotated using the Arabidopsis genome indicated that several HR-related orthologues of pathogenesis-related proteins, transcription factors, mitogen-activated protein kinases, and defense proteins were significantly expressed in leaves that formed local lesions. Here, we also provide new insights into the replication progression of a tospovirus and the molecular regulation of the C. quinoa response to virus infection.

  18. Phylogeography of Rift Valley Fever virus in Africa reveals multiple introductions in Senegal and Mauritania.

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    P O Ly Soumaré

    Full Text Available Rift Valley Fever (RVF virus (Family Bunyaviridae is an arthropod-borne RNA virus that infects primarily domestic ruminants and occasionally humans. RVF epizootics are characterized by numerous abortions and mortality among young animals. In humans, the illness is usually characterized by a mild self-limited febrile illness, which could progress to more serious complications. RVF virus is widespread and endemic in many regions of Africa. In Western Africa, several outbreaks have been reported since 1987 when the first major one occurred at the frontier of Senegal and Mauritania. Aiming to evaluate the spreading and molecular epidemiology in these countries, RVFV isolates from 1944 to 2008 obtained from 18 localities in Senegal and Mauritania and 15 other countries were investigated. Our results suggest that a more intense viral activity possibly took place during the last century compared to the recent past and that at least 5 introductions of RVFV took place in Senegal and Mauritania from distant African regions. Moreover, Barkedji in Senegal was possibly a hub associated with the three distinct entries of RVFV in West Africa.

  19. Rapid identification of Australian bunyavirus isolates belonging to the Simbu serogroup using indirect ELISA formats.

    Science.gov (United States)

    Blacksell, S D; Lunt, R A; White, J R

    1997-06-01

    The Bunyavirus genus, belonging to the Bunyaviridae family, is comprised of a large group of antigenically and geographically disparate arthropod-borne viruses of medical and veterinary significance. In Australia, viruses belonging to the Simbu serogroup of the Bunyavirus genus, Akabane, Tinaroo, Peaton, Aino, Douglas, Thimiri and Facey's Paddock have been isolated. In this communication we describe two indirect ELISAs, referred to as the Simbu serogroup ELISA (SG-ELISA), and the Simbu typing ELISA (ST-ELISA), for the identification of these Simbu serogroup viruses. Infected cell lysate antigens prepared from Simbu serogroup virus isolates were assessed in the SG-ELISA for reactivity with a mouse monoclonal antibody (4H9/B11/F1). The monoclonal antibody reacted strongly with all Australian members of Simbu serogroup reference viruses and is proposed for use as a serogrouping reagent for Simbu viruses. Furthermore, the ST-ELISA enabled specific identification of viruses from within this group by recognition of characteristic reaction patterns between infected cell lysate antigens and a panel of polyclonal antisera raised to Simbu serogroup viruses.

  20. Genetic characterization of Aino and Peaton virus field isolates reveals a genetic reassortment between these viruses in nature.

    Science.gov (United States)

    Yanase, Tohru; Aizawa, Maki; Kato, Tomoko; Yamakawa, Makoto; Shirafuji, Hiroaki; Tsuda, Tomoyuki

    2010-10-01

    Sequence determination and phylogenetic analysis were conducted using the S, M and L RNA segments of the 10 Aino, 6 Peaton and 1 Sango virus (AINOV, PEAV and SANV) field isolates of the genus Orthobunyavirus in the family Bunyaviridae, respectively. The Japanese AINOV strains were genetically stable, but the sequence differences between the Japanese and Australian AINOV strains were considerably larger than those among the Japanese AINOV strains. A similar result was found in the genetic relationship among Japanese and Australian PEAVs, and SANV which was isolated in Nigeria and was thought as a synonym of PEAV, suggesting that geographic separation contributed significantly to the evolution of those viruses. The Australian AINOV strain B7974 is more closely related to the Australian PEAV strain CSIRO110 than to the Japanese AINOV strains in the S and L RNA segments, while the phylogenetic position of the M RNA segment of the B7974 strain was clustered with those of the Japanese AINOV strains. Our findings indicate that the B7974 strain is a reassortment with the M RNA segment derived from AINOV and the S and L RNA segments derived from an Australian PEAV. (c) 2010 Elsevier B.V. All rights reserved.

  1. A large-scale serological survey of Akabane virus infection in cattle, yak, sheep and goats in China.

    Science.gov (United States)

    Wang, Jidong; Blasdell, Kim R; Yin, Hong; Walker, Peter J

    2017-08-01

    Akabane virus (AKAV) is a member of the Simbu serogroup, classified in the genus Orthobunyavirus, family Bunyaviridae. AKAV infection can cause abortion, stillbirth, and congenital arthrogryposis and hydranencephaly in cattle and sheep. The distribution and prevalence of AKAV infection in China is still unknown. A total of 2731 sera collected from 2006 to 2015 in 24 provinces of China from cattle, sheep, goats and yak were examined by serum neutralisation test. The overall seroprevalence rates for AKAV antibodies were 21.3% in cattle (471/2215) and 12.0% (17/142) in sheep or goats, and 0% in yak (0/374). The results indicated widespread AKAV infection in China among cattle and sheep but yak appear to have a low risk of infection. Using a selection of 50 AKAV-positive and 25 AKAV-negative cattle sera, neutralisation tests were also conducted to detect antibodies to several other Simbu serogroup bunyaviruses and closely related Leanyer virus. Although inconclusive, the data suggest that both Aino virus and Peaton virus, which have been reported previously in Japan and Korea, may also be present in cattle in China. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  2. Molecular epidemiological analyses of the teratogenic Aino virus based on the sequences of a small RNA segment.

    Science.gov (United States)

    Yamakawa, Makoto; Yanase, Tohru; Kato, Tomoko; Tsuda, Tomoyuki

    2008-05-25

    The sequences of a small RNA segment of Aino virus isolates were analyzed to define the molecular epidemiology and genetic relationships to other species in the genus Orthobunyavirus in the family Bunyaviridae. The nucleotide and amino acid sequences of the segment were highly conserved among strains isolated from 1964 to 2002 in Japan. These Japanese isolates were segregated into two distinct lineages, one containing the prototype strain JaNAr28 isolated in 1964 and the other containing strains isolated after 1986, by phylogenetic analysis based on the nucleocapsid gene sequences. Japanese strains isolated after 1986 were rather more closely related to Kaikalur virus isolated in India in 1971 than to strain JaNAr28. On the other hand, an Australian strain, B7974, was closely related to Peaton virus. The B7974 strain might have been generated by inter-serotype genetic reassortment between Aino and Peaton viruses in Australia during their evolution. However, recent Aino virus strains isolated in Japan appear to be genetically stable.

  3. Intracellular localization of Crimean-Congo Hemorrhagic Fever (CCHF virus glycoproteins

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    Fernando Lisa

    2005-04-01

    Full Text Available Abstract Background Crimean-Congo Hemorrhagic Fever virus (CCHFV, a member of the genus Nairovirus, family Bunyaviridae, is a tick-borne pathogen causing severe disease in humans. To better understand the CCHFV life cycle and explore potential intervention strategies, we studied the biosynthesis and intracellular targeting of the glycoproteins, which are encoded by the M genome segment. Results Following determination of the complete genome sequence of the CCHFV reference strain IbAr10200, we generated expression plasmids for the individual expression of the glycoproteins GN and GC, using CMV- and chicken β-actin-driven promoters. The cellular localization of recombinantly expressed CCHFV glycoproteins was compared to authentic glycoproteins expressed during virus infection using indirect immunofluorescence assays, subcellular fractionation/western blot assays and confocal microscopy. To further elucidate potential intracellular targeting/retention signals of the two glycoproteins, GFP-fusion proteins containing different parts of the CCHFV glycoprotein were analyzed for their intracellular targeting. The N-terminal glycoprotein GN localized to the Golgi complex, a process mediated by retention/targeting signal(s in the cytoplasmic domain and ectodomain of this protein. In contrast, the C-terminal glycoprotein GC remained in the endoplasmic reticulum but could be rescued into the Golgi complex by co-expression of GN. Conclusion The data are consistent with the intracellular targeting of most bunyavirus glycoproteins and support the general model for assembly and budding of bunyavirus particles in the Golgi compartment.

  4. Heartland virus infection in hamsters deficient in type I interferon signaling: Protracted disease course ameliorated by favipiravir.

    Science.gov (United States)

    Westover, Jonna B; Rigas, Johanna D; Van Wettere, Arnaud J; Li, Rong; Hickerson, Brady T; Jung, Kie-Hoon; Miao, Jinxin; Reynolds, Erin S; Conrad, Bettina L; Nielson, Skot; Furuta, Yousuke; Thangamani, Saravanan; Wang, Zhongde; Gowen, Brian B

    2017-11-01

    Heartland virus (HRTV) is an emerging tick-borne virus (Bunyaviridae, Phlebovirus) that has caused sporadic cases of human disease in several central and mid-eastern states of America. Animal models of HRTV disease are needed to gain insights into viral pathogenesis and advancing antiviral drug development. Presence of clinical disease following HRTV challenge in hamsters deficient in STAT2 function underscores the important role played by type I interferon-induced antiviral responses. However, the recovery of most of the infected animals suggests that other mechanisms to control infection and limit disease offer substantial protection. The most prominent disease sign with HRTV infection in STAT2 knockout hamsters was dramatic weight loss with clinical laboratory and histopathology demonstrating acute inflammation in the spleen, lymph node, liver and lung. Finally, we show that HRTV disease in hamsters can be prevented by the use of favipiravir, a promising broad-spectrum antiviral in clinical development for the treatment of influenza. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Hantaviruses: rediscovery and new beginnings.

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    Yanagihara, Richard; Gu, Se Hun; Arai, Satoru; Kang, Hae Ji; Song, Jin-Won

    2014-07-17

    Virus and host gene phylogenies, indicating that antigenically distinct hantaviruses (family Bunyaviridae, genus Hantavirus) segregate into clades, which parallel the molecular evolution of rodents belonging to the Murinae, Arvicolinae, Neotominae and Sigmodontinae subfamilies, suggested co-divergence of hantaviruses and their rodent reservoirs. Lately, this concept has been vigorously contested in favor of preferential host switching and local host-specific adaptation. To gain insights into the host range, spatial and temporal distribution, genetic diversity and evolutionary origins of hantaviruses, we employed reverse transcription-polymerase chain reaction to analyze frozen, RNAlater(®)-preserved and ethanol-fixed tissues from 1546 shrews (9 genera and 47 species), 281 moles (8 genera and 10 species) and 520 bats (26 genera and 53 species), collected in Europe, Asia, Africa and North America during 1980-2012. Thus far, we have identified 24 novel hantaviruses in shrews, moles and bats. That these newfound hantaviruses are geographically widespread and genetically more diverse than those harbored by rodents suggests that the evolutionary history of hantaviruses is far more complex than previously conjectured. Phylogenetic analyses indicate four distinct clades, with the most divergent comprising hantaviruses harbored by the European mole and insectivorous bats, with evidence for both co-divergence and host switching. Future studies will provide new knowledge about the transmission dynamics and pathogenic potential of these newly discovered, still-orphan, non-rodent-borne hantaviruses. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Ultrastructural, Antigenic and Physicochemical Characterization of the Mojuí dos Campos (Bunyavirus Isolated from Bat in the Brazilian Amazon Region

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    Wanzeller Ana LM

    2002-01-01

    Full Text Available The Mojuí dos Campos virus (MDCV was isolated from the blood of an unidentified bat (Chiroptera captured in Mojuí dos Campos, Santarém, State of Pará, Brazil, in 1975 and considerated to be antigenically different from other 102 arboviruses belonging to several antigenic groups isolated in the Amazon region or another region by complement fixation tests. The objective of this work was to develop a morphologic, an antigenic and physicochemical characterization of this virus. MDCV produces cytopathic effect in Vero cells, 24 h post-infection (p.i, and the degree of cellular destruction increases after a few hours. Negative staining electron microscopy of the supernatant of Vero cell cultures showed the presence of coated viral particles with a diameter of around 98 nm. Ultrathin sections of Vero cells, and brain and liver of newborn mice infected with MDCV showed an assembly of the viral particles into the Golgi vesicles. The synthesis kinetics of the proteins for MDCV were similar to that observed for other bunyaviruses, and viral proteins could be detected as early as 6 h p.i. Our results reinforce the original studies which had classified MDCV in the family Bunyaviridae, genus Bunyavirus as an ungrouped virus, and it may represent the prototype of a new serogroup.

  7. Development of a Rift Valley fever virus viremia challenge model in sheep and goats.

    Science.gov (United States)

    Weingartl, Hana M; Miller, Myrna; Nfon, Charles; Wilson, William C

    2014-04-25

    Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, causes severe to fatal disease in newborn ruminants, as well as abortions in pregnant animals; both preventable by vaccination. Availability of a challenge model is a pre-requisite for vaccine efficacy trials. Several modes of inoculation with RVFV ZH501 were tested on goats and sheep. Differences in development of infectious viremia were observed between animals inoculated with RVFV produced in mosquito C6/36 cells compared to Vero E6 cell-produced inoculum. Only C6/36-RVFV inoculation led to development of viremia in all inoculated sheep and goats. The C6/36 cell-produced RVFV appeared to be more infectious with earlier onset of viremia, especially in sheep, and may also more closely represent a field situation. Goats were somewhat more resistant to the disease development with lower and shorter infectious virus viremia, and with only some animals developing transient increase in rectal temperature in contrast to sheep. In conclusion, a challenge protocol suitable for goat and sheep vaccine efficacy studies was developed using subcutaneous inoculation of 10(7)PFU per animal with RVFV ZH501 produced in C6/36 cells. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  8. Analyses of Entry Mechanisms of Novel Emerging Viruses Using Pseudotype VSV System.

    Science.gov (United States)

    Tani, Hideki

    2014-06-01

    Emerging infectious diseases include newly identified diseases caused by previously unknown organisms or diseases found in new and expanding geographic areas. Viruses capable of causing clinical disease associated with fever and bleeding are referred to as viral hemorrhagic fevers (VHFs). Arenaviruses and Bunyaviruses, both belonging to families classified as VHFs are considered major etiologies of hemorrhagic fevers caused by emerging viruses; having significant clinical and public health impact. Because these viruses are categorized as Biosafety Level (BSL) 3 and 4 pathogens, restricting their use, biological studies including therapeutic drug and vaccine development have been impeded. Due to these restrictions and the difficulties in handling such live viruses, pseudotype viruses bearing envelope proteins of VHF viruses have been developed using vesicular stomatitis virus (VSV) as a surrogate system. Here, we report the successful developments of two pseudotype VSV systems; bearing the envelope proteins of Lujo virus and severe fever with thrombocytopenia syndrome (SFTS) virus, both recently identified viruses of the family Arenaviridae and Bunyaviridae, respectively. My presentation will summarize the characterization of the envelope proteins of Lujo virus including its cellular receptor use and cell entry mechanisms. In addition, I will also present a brief introduction of SFTS reported in Japan and the diagnostic studies in progress using these newly pseudotype VSV system.

  9. A preliminary study of viral metagenomics of French bat species in contact with humans: identification of new mammalian viruses.

    Science.gov (United States)

    Dacheux, Laurent; Cervantes-Gonzalez, Minerva; Guigon, Ghislaine; Thiberge, Jean-Michel; Vandenbogaert, Mathias; Maufrais, Corinne; Caro, Valérie; Bourhy, Hervé

    2014-01-01

    The prediction of viral zoonosis epidemics has become a major public health issue. A profound understanding of the viral population in key animal species acting as reservoirs represents an important step towards this goal. Bats harbor diverse viruses, some of which are of particular interest because they cause severe human diseases. However, little is known about the diversity of the global population of viruses found in bats (virome). We determined the viral diversity of five different French insectivorous bat species (nine specimens in total) in close contact with humans. Sequence-independent amplification, high-throughput sequencing with Illumina technology and a dedicated bioinformatics analysis pipeline were used on pooled tissues (brain, liver and lungs). Comparisons of the sequences of contigs and unassembled reads provided a global taxonomic distribution of virus-related sequences for each sample, highlighting differences both within and between bat species. Many viral families were present in these viromes, including viruses known to infect bacteria, plants/fungi, insects or vertebrates, the most relevant being those infecting mammals (Retroviridae, Herpesviridae, Bunyaviridae, Poxviridae, Flaviviridae, Reoviridae, Bornaviridae, Picobirnaviridae). In particular, we detected several new mammalian viruses, including rotaviruses, gammaretroviruses, bornaviruses and bunyaviruses with the identification of the first bat nairovirus. These observations demonstrate that bats naturally harbor viruses from many different families, most of which infect mammals. They may therefore constitute a major reservoir of viral diversity that should be analyzed carefully, to determine the role played by bats in the spread of zoonotic viral infections.

  10. A preliminary study of viral metagenomics of French bat species in contact with humans: identification of new mammalian viruses.

    Directory of Open Access Journals (Sweden)

    Laurent Dacheux

    Full Text Available The prediction of viral zoonosis epidemics has become a major public health issue. A profound understanding of the viral population in key animal species acting as reservoirs represents an important step towards this goal. Bats harbor diverse viruses, some of which are of particular interest because they cause severe human diseases. However, little is known about the diversity of the global population of viruses found in bats (virome. We determined the viral diversity of five different French insectivorous bat species (nine specimens in total in close contact with humans. Sequence-independent amplification, high-throughput sequencing with Illumina technology and a dedicated bioinformatics analysis pipeline were used on pooled tissues (brain, liver and lungs. Comparisons of the sequences of contigs and unassembled reads provided a global taxonomic distribution of virus-related sequences for each sample, highlighting differences both within and between bat species. Many viral families were present in these viromes, including viruses known to infect bacteria, plants/fungi, insects or vertebrates, the most relevant being those infecting mammals (Retroviridae, Herpesviridae, Bunyaviridae, Poxviridae, Flaviviridae, Reoviridae, Bornaviridae, Picobirnaviridae. In particular, we detected several new mammalian viruses, including rotaviruses, gammaretroviruses, bornaviruses and bunyaviruses with the identification of the first bat nairovirus. These observations demonstrate that bats naturally harbor viruses from many different families, most of which infect mammals. They may therefore constitute a major reservoir of viral diversity that should be analyzed carefully, to determine the role played by bats in the spread of zoonotic viral infections.

  11. Evasion of antiviral immunity through sequestering of TBK1/IKKε/IRF3 into viral inclusion bodies.

    Science.gov (United States)

    Wu, Xiaodong; Qi, Xian; Qu, Bingqian; Zhang, Zerui; Liang, Mifang; Li, Chuan; Cardona, Carol J; Li, Dexin; Xing, Zheng

    2014-03-01

    Cells are equipped with pattern recognition receptors (PRRs) such as the Toll-like and RIG-I-like receptors that mount innate defenses against viruses. However, viruses have evolved multiple strategies to evade or thwart host antiviral responses. Viral inclusion bodies (IBs), which are accumulated aggregates of viral proteins, are commonly formed during the replication of some viruses in infected cells, but their role in viral immune evasion has rarely been explored. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging febrile illness caused by a novel phlebovirus in the Bunyaviridae. The SFTS viral nonstructural protein NSs can suppress host beta interferon (IFN-β) responses. NSs can form IBs in infected and transfected cells. Through interaction with tank-binding kinase 1 (TBK1), viral NSs was able to sequester the IKK complex, including IKKε and IRF3, into IBs, although NSs did not interact with IKKε or IRF3 directly. When cells were infected with influenza A virus, IRF3 was phosphorylated and active phosphorylated IRF3 (p-IRF3) was translocated into the nucleus. In the presence of NSs, IRF3 could still be phosphorylated, but p-IRF3 was trapped in cytoplasmic IBs, resulting in reduced IFN-β induction and enhanced viral replication. Sequestration of the IKK complex and active IRF3 into viral IBs through the interaction of NSs and TBK1 is a novel mechanism for viral evasion of innate immunity.

  12. Arbovirus investigations in Argentina, 1977-1980. III. Identification and characterization of viruses isolated, including new subtypes of western and Venezuelan equine encephalitis viruses and four new bunyaviruses (Las Maloyas, Resistencia, Barranqueras, and Antequera).

    Science.gov (United States)

    Calisher, C H; Monath, T P; Mitchell, C J; Sabattini, M S; Cropp, C B; Kerschner, J; Hunt, A R; Lazuick, J S

    1985-09-01

    Forty viruses isolated from mosquitoes between 1977 and 1980 in Argentina have been identified and characterized. Nineteen strains of VEE virus, identical by neutralization (N) tests, were shown by hemagglutination-inhibition tests with anti-E2 glycoprotein sera to represent a new subtype VI of the VEE complex. RNA oligonucleotide fingerprints of this virus were distinct from subtype I viruses. The virus was not lethal for English short-haired guinea pigs, indicating that it is probably not equine-virulent. Three strains of a member of the WEE virus complex were shown to differ by N tests in 1 direction from prototype WEE virus. The new WEE subtype was also found to be distinct by RNA oligonucleotide mapping. Its vector relationships indicate that it is an enzootic virus, and it has not been associated with equine disease. A new member of the Anopheles A serogroup was identified, shown to be most closely related to Lukuni and Col An 57389 viruses, and given the name Las Maloyas virus. A strain of Para virus (Bunyaviridae, Bunyavirus) was identified. Six isolates, representing 3 new viruses morphologically resembling bunyaviruses are described; the names Antequera, Barranqueras, and Resistencia are proposed for these agents, which were all isolated from Culex (Melanoconion) delpontei in Chaco Province. No serologic relationships between these viruses and other bunyaviruses were found. Since they are antigenically interrelated, they form a new (Antequera) serogroup. Eight Gamboa serogroup viruses and 2 strains of St. Louis encephalitis virus were also identified.

  13. Management of spotted wilt vectored by Frankliniella fusca (Thysanoptera: Thripidae) in Virginia market-type peanut.

    Science.gov (United States)

    Hurt, C A; Brandenburg, R L; Jordan, D L; Kennedy, G G; Bailey, J E

    2005-10-01

    Field tests were conducted during 2001 and 2002 in northeastern North Carolina to evaluate the impact of cultural practices and in-furrow insecticides on the incidence of Tomato spotted wilt virus (genus Tospovirus, family Bunyaviridae, TSWV), which is transmitted to peanut, Arachis hypogaea L., primarily by tobacco thrips, Frankliniella fusca Hinds (Thysanoptera: Thripidae). Treatments included in row plant populations of 7, 13, and 17 plants per meter; the virginia market-type 'NC V-11' and 'Perry'; planting dates of early and late May; and phorate and aldicarb insecticide applied in-furrow. The incidence of plants expressing visual symptoms of spotted wilt was recorded from mid-June through mid-September. Treatment factors that reduced the incidence of symptoms of plants expressing spotted wilt symptoms included establishing higher plant densities, delaying planting from early May until late May, and applying the in-furrow insecticide phorate. Peanut cultivar did not have a consistent, significant effect on the incidence of symptomatic plants in this experiment.

  14. Second generation peanut genotypes resistant to thrips-transmitted tomato spotted wilt virus exhibit tolerance rather than true resistance and differentially affect thrips fitness.

    Science.gov (United States)

    Shrestha, Anita; Srinivasan, Rajagopalbabu; Sundaraj, Sivamani; Culbreath, Albert K; Riley, David G

    2013-04-01

    Spotted wilt disease caused by Tomato spotted wilt virus (TSWV) (family Bunyaviridae; genus Tospovirus) is a major constraint to peanut (Arachis hypogaea L.) production in the southeastern United States. Reducing yield losses to TSWV has heavily relied on planting genotypes that reduce the incidence of spotted wilt disease. However, mechanisms conferring resistance to TSWV have not been identified in these genotypes. Furthermore, no information is available on how these genotypes influence thrips fitness. In this study, we investigated the effects of newly released peanut genotypes (Georganic, GA-06G, Tifguard, and NC94022) with field resistance to TSWV and a susceptible genotype (Georgia Green) on tobacco thrips, Frankliniella fusca (Hinds), fitness, and TSWV incidence. Thrips-mediated transmission resulted in TSWV infection in both TSWV-resistant and susceptible genotypes and they exhibited typical TSWV symptoms. However, some resistant genotypes had reduced viral loads (fewer TSWV N-gene copies) than the susceptible genotype. F. fusca larvae acquired TSWV from resistant and susceptible genotypes indicating that resistant genotypes also can serve as inoculum sources. Unlike resistant genotypes in other crops that produce local lesions (hypersensitive reaction) upon TSWV infection, widespread symptom development was noticed in peanut genotypes. Results indicated that the observed field resistance in peanut genotypes could be because of tolerance. Further, fitness studies revealed some, but not substantial, differences in thrips adult emergence rates and developmental time between resistant and susceptible genotypes. Thrips head capsule length and width were not different when reared on different genotypes.

  15. Current status of Crimean-Congo haemorrhagic fever in the World Health Organization Eastern Mediterranean Region: issues, challenges, and future directions

    Directory of Open Access Journals (Sweden)

    Seif S. Al-Abri

    2017-05-01

    Full Text Available Crimean-Congo haemorrhagic fever (CCHF is the most widespread, tick-borne viral disease affecting humans. The disease is endemic in many regions, such as Africa, Asia, Eastern and Southern Europe, and Central Asia. Recently, the incidence of CCHF has increased rapidly in the countries of the World Health Organization Eastern Mediterranean Region (WHO EMR, with sporadic human cases and outbreaks of CCHF being reported from a number of countries in the region. Despite the rapidly growing incidence of the disease, there are currently no accurate data on the burden of the disease in the region due to the different surveillance systems used for CCHF in these countries. In an effort to increase our understanding of the epidemiology and risk factors for the transmission of the CCHF virus (CCHFV; a Nairovirus of the family Bunyaviridae in the WHO EMR, and to identify the current knowledge gaps that are hindering effective control interventions, a sub-regional meeting was organized in Muscat, Oman, from December 7 to 9, 2015. This article summarizes the current knowledge of the disease in the region, identifies the knowledge gaps that present challenges for the prevention and control of CCHFV, and details a strategic framework for research and development activities that would be necessary to curb the ongoing and new threats posed by CCHFV.

  16. Crimean-Congo haemorrhagic fever virus: sequence analysis of the small RNA segments from a collection of viruses world wide.

    Science.gov (United States)

    Hewson, R; Chamberlain, J; Mioulet, V; Lloyd, G; Jamil, B; Hasan, R; Gmyl, A; Gmyl, L; Smirnova, S E; Lukashev, A; Karganova, G; Clegg, C

    2004-06-15

    Crimean-Congo haemorrhagic fever virus (CCHFv) is a member of the genus Nairovirus in the family Bunyaviridae. It possesses a tripartite, single stranded RNA genome of negative polarity consisting of large (L), medium (M) and small (S) segments. CCHF virus is enzootic in life stock and wild animals in many parts of the Middle East, Asia and Africa and is also recognised in Southeast Europe. Severe disease, manifest as haemorrhagic fever and high mortality rates (up to 50%), is only recognised in humans. We have determined the complete sequence of the small genomic RNA segment from several strains of CCHF virus from outbreaks in Pakistan 2000, Baghdad 1976 and Uzbekistan 1967. Phylogenetic analysis of three datasets of sequences from the small genomic RNA segment available from a range of strains indicates that they can be divided into seven subtypes. Superimposed on this pattern are links between distant geographic locations, pointing to the existence of a global reservoir of CCHFv. In some cases these links may originate from trade in livestock, and long-distance carriage of virus or infected ticks during bird migration.

  17. Crimean-Congo haemorrhagic fever virus in Kazakhstan (1948-2013).

    Science.gov (United States)

    Nurmakhanov, Talgat; Sansyzbaev, Yerlan; Atshabar, Bakhyt; Deryabin, Pavel; Kazakov, Stanislav; Zholshorinov, Aitmagambet; Matzhanova, Almagul; Sadvakassova, Alya; Saylaubekuly, Ratbek; Kyraubaev, Kakimzhan; Hay, John; Atkinson, Barry; Hewson, Roger

    2015-09-01

    Crimean-Congo haemorrhagic fever (CCHF) is a pathogenic and often fatal arboviral disease with a distribution spanning large areas of Africa, Europe and Asia. The causative agent is a negative-sense single-stranded RNA virus classified within the Nairovirus genus of the Bunyaviridae family. Cases of CCHF have been officially recorded in Kazakhstan since the disease was first officially reported in modern medicine. Serological surveillance of human and animal populations provide evidence that the virus was perpetually circulating in a local enzoonotic cycle involving mammals, ticks and humans in the southern regions of the country. Most cases of human disease were associated with agricultural professions such as farming, shepherding and fruit-picking; the typical route of infection was via tick-bite although several cases of contact transmission associated with caring for sick patients have been documented. In total, 704 confirmed human cases of CCHF have been registered in Kazakhstan from 1948-2013 with an overall case fatality rate of 14.8% for cases with a documented outcome. The southern regions of Kazakhstan should be considered endemic for CCHF with cases reported from these territories on an annual basis. Modern diagnostic technologies allow for rapid clinical diagnosis and for surveillance studies to monitor for potential expansion in known risk areas. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  18. Current status of Crimean-Congo haemorrhagic fever in the World Health Organization Eastern Mediterranean Region: issues, challenges, and future directions.

    Science.gov (United States)

    Al-Abri, Seif S; Abaidani, Idris Al; Fazlalipour, Mehdi; Mostafavi, Ehsan; Leblebicioglu, Hakan; Pshenichnaya, Natalia; Memish, Ziad A; Hewson, Roger; Petersen, Eskild; Mala, Peter; Nhu Nguyen, Tran Minh; Rahman Malik, Mamunur; Formenty, Pierre; Jeffries, Rosanna

    2017-05-01

    Crimean-Congo haemorrhagic fever (CCHF) is the most widespread, tick-borne viral disease affecting humans. The disease is endemic in many regions, such as Africa, Asia, Eastern and Southern Europe, and Central Asia. Recently, the incidence of CCHF has increased rapidly in the countries of the World Health Organization Eastern Mediterranean Region (WHO EMR), with sporadic human cases and outbreaks of CCHF being reported from a number of countries in the region. Despite the rapidly growing incidence of the disease, there are currently no accurate data on the burden of the disease in the region due to the different surveillance systems used for CCHF in these countries. In an effort to increase our understanding of the epidemiology and risk factors for the transmission of the CCHF virus (CCHFV; a Nairovirus of the family Bunyaviridae) in the WHO EMR, and to identify the current knowledge gaps that are hindering effective control interventions, a sub-regional meeting was organized in Muscat, Oman, from December 7 to 9, 2015. This article summarizes the current knowledge of the disease in the region, identifies the knowledge gaps that present challenges for the prevention and control of CCHFV, and details a strategic framework for research and development activities that would be necessary to curb the ongoing and new threats posed by CCHFV. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. Viral RNA Silencing Suppression: The Enigma of Bunyavirus NSs Proteins.

    Science.gov (United States)

    Hedil, Marcio; Kormelink, Richard

    2016-07-23

    The Bunyaviridae is a family of arboviruses including both plant- and vertebrate-infecting representatives. The Tospovirus genus accommodates plant-infecting bunyaviruses, which not only replicate in their plant host, but also in their insect thrips vector during persistent propagative transmission. For this reason, they are generally assumed to encounter antiviral RNA silencing in plants and insects. Here we present an overview on how tospovirus nonstructural NSs protein counteracts antiviral RNA silencing in plants and what is known so far in insects. Like tospoviruses, members of the related vertebrate-infecting bunyaviruses classified in the genera Orthobunyavirus, Hantavirus and Phlebovirus also code for a NSs protein. However, for none of them RNA silencing suppressor activity has been unambiguously demonstrated in neither vertebrate host nor arthropod vector. The second part of this review will briefly describe the role of these NSs proteins in modulation of innate immune responses in mammals and elaborate on a hypothetical scenario to explain if and how NSs proteins from vertebrate-infecting bunyaviruses affect RNA silencing. If so, why this discovery has been hampered so far.

  20. Seasonal Population Dynamics of Thrips (Thysanoptera) in Wisconsin and Iowa Soybean Fields.

    Science.gov (United States)

    Bloomingdale, Chris; Irizarry, Melissa D; Groves, Russell L; Mueller, Daren S; Smith, Damon L

    2017-02-01

    With the discovery of Neohydatothrips variabilis (Beach) as a vector of Soybean vein necrosis virus (Family Bunyaviridae Genus Tospovirus), a relatively new pathogen of soybean, a multiyear study was initiated in Wisconsin (2013 and 2014) and Iowa (2014 and 2015) to determine the phenology and species composition of thrips in soybean fields. Yellow sticky card traps were used to sample thrips at regular intervals in five counties within each state's primary soybean-growing region. The assemblage of species present in Wisconsin was determined in all site-years, revealing that N. variabilis and other known vectors of tospoviruses were a relatively small percentage of the total thrips captures in 2013 (1.6%) and 2014 (3.6%). A repeated measures analysis was conducted on cumulative proportion thrips capture data within each state's sampling year to investigate differences in phenology, and standardized cumulative insect days were analyzed between sampling years within each state to determine differences in the relative magnitude of populations. Distinct seasonal trends were not detected based on location, as originally hypothesized, and thrips populations varied significantly among locations and between years. These results suggest that thrips populations may be overwintering in northern climates instead of relying solely on migrations to colonize northern soybean fields. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Detection of Tomato spotted wilt virus in its vector Frankliniella occidentalis by reverse transcription-polymerase chain reaction.

    Science.gov (United States)

    Mason, Giovanna; Roggero, Piero; Tavella, Luciana

    2003-04-01

    A method for rapid and reliable detection of Tomato spotted wilt virus (TSWV) (Tospovirus, Bunyaviridae) in its vector Frankliniella occidentalis (Thysanoptera Thripidae) would be a useful tool for studying the epidemiology of this virus. A RT-PCR method developed for this purpose is reported. The method was tested on thrips involved in laboratory transmission trials and on thrips collected in the field, whose capability to transmit TSWV was checked previously by leaf disk assays. The RT-PCR results were consistent with the results obtained by the leaf disk assays. Among thrips involved in laboratory experiments, 97% of the adults that transmitted TSWV were positive by RT-PCR; as did some non-transmitter adults reacted, whereas among field-collected thrips only the individuals able to transmit were positive by RT-PCR. In addition, healthy thrips were allowed to feed as adults on virus-infected leaves for 48 h, and then examined by RT-PCR immediately or after starving or feeding on virus-free plants for various times, to determine if virus ingested (but not transmissible) was also detectable. The virus was detectable immediately after the feed or within 12 and 24 h for individuals starved or fed on virus-free plants, respectively, but not after those periods. Thus, the method could detect rapidly and reliably the virus in vectors from the field, providing 24 h of starving to avoid positive RT-PCR results from thrips simply carrying the virus.

  2. Global status of tospovirus epidemics in diverse cropping systems: successes achieved and challenges ahead.

    Science.gov (United States)

    Pappu, H R; Jones, R A C; Jain, R K

    2009-05-01

    The diseases caused by thrips-transmitted tospoviruses (genus Tospovirus, family Bunyaviridae) are a major constraint to production of important vegetable, legume and ornamental crops in different parts of the world. Tospoviruses are characterized by having tripartite RNA genomes and utilizing both negative and ambisense genome expression strategies. Their often wide and overlapping host ranges, emergence of resistance-breaking strains, circulative and propagative relationship with polyphagous thrips vectors, and difficulties in predicting their outbreaks pose challenges to development and implementation of effective management programmes. Despite these challenges, for a few tospoviruses, considerable progress has been made in successful development and deployment of practical and effective integrated disease management programmes. This has been due to increased understanding of their molecular biology, plant-virus and virus-vector interactions and epidemiology, and to identification of risk factors that contribute to increased disease incidence and of tactics to mitigate those risk factors. However, challenges remain as resistance-breaking or other new strains of known tospoviruses and completely new tospovirus species continue to be described from various parts of the world and have the potential to cause damaging epidemics. To protect crops from the losses caused by severe tospovirus outbreaks, continued vigilance is required to identify and characterize these emerging tospoviruses, determine their impact on crop production, understand their epidemiologies and develop, evaluate and implement control measures to reduce their impact on crop production.

  3. Evolution and structure of Tomato spotted wilt virus populations: evidence of extensive reassortment and insights into emergence processes.

    Science.gov (United States)

    Tentchev, Diana; Verdin, Eric; Marchal, Cécile; Jacquet, Monique; Aguilar, Juan M; Moury, Benoît

    2011-04-01

    Tomato spotted wilt virus (TSWV; genus Tospovirus, family Bunyaviridae) genetic diversity was evaluated by sequencing parts of the three RNA genome segments of 224 isolates, mostly from pepper and tomato crops in southern Europe. Eighty-three per cent of the isolates showed consistent clustering into three clades, corresponding to their geographical origin, Spain, France or the USA, for the three RNA segments. In contrast, the remaining 17% of isolates did not belong to the same clade for the three RNA segments and were shown to be reassortants. Among them, eight different reassortment patterns were observed. Further phylogenetic analyses provided insights into the dynamic processes of the worldwide resurgence of TSWV that, since the 1980s, has followed the worldwide dispersal of the western flower thrips (Frankliniella occidentalis) tospovirus vector. For two clades composed essentially of Old World (OW) isolates, tree topology suggested a local re-emergence of indigenous TSWV populations following F. occidentalis introductions, while it could not be excluded that the ancestors of two other OW clades were introduced from North America contemporarily with F. occidentalis. Finally, estimation of the selection intensity that has affected the evolution of the NSs and nucleocapsid proteins encoded by RNA S of TSWV suggests that the former could be involved in the breakdown of resistance conferred by the Tsw gene in pepper.

  4. Temporal dynamics of iris yellow spot virus and its vector, Thrips tabaci (Thysanoptera: Thripidae), in seeded and transplanted onion fields.

    Science.gov (United States)

    Hsu, Cynthia L; Hoepting, Christine A; Fuchs, Marc; Shelton, Anthony M; Nault, Brian A

    2010-04-01

    Onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), can reduce onion bulb yield and transmit iris yellow spot virus (IYSV) (Bunyaviridae: Tospovirus), which can cause additional yield losses. In New York, onions are planted using seeds and imported transplants. IYSV is not seed transmitted, but infected transplants have been found in other U.S. states. Transplants are also larger than seeded onions early in the season, and thrips, some of which may be viruliferous, may preferentially colonize larger plants. Limited information is available on the temporal dynamics of IYSV and its vector in onion fields. In 2007 and 2008, T. tabaci and IYSV levels were monitored in six seeded and six transplanted fields. We found significantly more thrips in transplanted fields early in the season, but by the end of the season seeded fields had higher levels of IYSV. The percentage of sample sites with IYSV-infected plants remained low (thrips in August and September were better predictors of final IYSV levels than early season thrips densities. For 2007 and 2008, the time onions were harvested may have been more important in determining IYSV levels than whether the onions were seeded or transplanted. Viruliferous thrips emigrating from harvested onion fields into nonharvested ones may be increasing the primary spread of IYSV in late-harvested onions. Managing T. tabaci populations before harvest, and manipulating the spatial arrangement of fields based on harvest date could mitigate the spread of IYSV.

  5. Host plant, temperature, and photoperiod effects on ovipositional preference of Frankliniella occidentalis and Frankliniella fusca (Thysanoptera: Thripidae).

    Science.gov (United States)

    Chaisuekul, C; Riley, D G

    2005-12-01

    Host plant effects of tomato, Lycopersicon esculentum Mill., and chickweed, Stellaria media (L.) Vill., foliage infected and uninfected with Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV) on the ovipositional preferences of western flower thrips, Frankliniella occidentalis (Pergande), and tobacco thrips, Frankliniella fusca (Hinds), were investigated for whole plants in the greenhouse. In addition, the preference for leaf disks from the same host plants was investigated under a range of temperatures, 15-30 degrees C at a photoperiod of 12:12 (L:D) h, and at three photoperiods, 6:18, 12:12, and 18:6, at 20 degrees C in no-choice and choice studies conducted in growth chambers. In a choice test, F. fusca oviposited significantly more eggs per whole plant foliage over a 7-d period than F. occidentalis by an average ratio of 3:1 over both tomato and chickweed. The optimum temperature for oviposition of F. occidentalis and F. fusca was 24.5 and 24.9 degrees C, respectively. Both species laid significantly more eggs under the longest daylight hours tested, 18:6, in the choice study. Temperature and photoperiod did not significantly interact in terms of thrips ovipositional preference. Ovipositional preference for chickweed or tomato foliage was different for each thrips species in the choice and no-choice tests. However, both thrips species laid significantly more eggs per square centimeter of leaf area in chickweed than in tomato in the whole plant choice test.

  6. Onion thrips (Thysanoptera: Thripidae): a global pest of increasing concern in onion.

    Science.gov (United States)

    Diaz-Montano, John; Fuchs, Marc; Nault, Brian A; Fail, József; Shelton, Anthony M

    2011-02-01

    During the past two decades, onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), has become a global pest of increasing concern in commercial onion (Allium cepa L.), because of its development of resistance to insecticides, ability to transmit plant pathogens, and frequency of producing more generations at high temperatures. T. tabaci feeds directly on leaves, causing blotches and premature senescence as well as distorted and undersized bulbs. T. tabaci can cause yield loss > 50% but can be even more problematic when it transmits Iris yellow spot virus (family Bunyaviridae, genus Tospovirus, IYSV). IYSV was identified in 1981 in Brazil and has spread to many important onion-producing regions of the world, including several U.S. states. IYSV symptoms include straw-colored, dry, tan, spindle- or diamond-shaped lesions on the leaves and scapes of onion plants and can cause yield loss up to 100%. Here, we review the biology and ecology of T. tabaci and discuss current management strategies based on chemical, biological, and cultural control as well as host resistance. Future directions for research in integrated pest management are examined and discussed.

  7. Bell and banana pepper exhibit mature-plant resistance to tomato spotted wilt Tospovirus transmitted by Frankliniella fusca (Thysanoptera: Thripidae).

    Science.gov (United States)

    Beaudoin, A L P; Kahn, N D; Kennedy, G G

    2009-02-01

    Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV) causes annual economic losses in pepper, Capsicum annuum L., across the southern United States and is transmitted by several species of thrips, including the tobacco thrips, Frankliniella fusca (Hinds). Reduced virus transmission and symptom severity as plant age increases is known as mature-plant resistance. TSWV transmission to pepper plants was examined in three and four age classes in field and greenhouse trials, respectively. In the field trial, 'Camelot' bell pepper plants were exposed to potentially viruliferous F. fusca 37, 51, or 65 d postsowing. Two greenhouse trials of Camelot bell and one trial each of 'Bounty' and 'Pageant' banana pepper plants were exposed to potentially viruliferous F. fusca, 43, 57, 71, or 85; 48, 62, 75, or 90; 42, 56, 70, or 84; and 43, 57, 71, or 85 d postsowing, respectively. Linear and hyperbolic regressions of percentage of infected plants per block on days postsowing indicated mature-plant resistance in all trials. All models were significant, but hyperbolic curves better fit the data than linear models. Hyperbolic models were used to calculate the number of days posttransplant at which a 50% decrease from the predicted percentage of infected plants at transplant age (42 d postsowing) was expected. This was referred to as days posttransplant-50 (DPT50). DPRT50 occurred within 9 days posttransplant age for all trials, indicating that early TSWV management in pepper is critical.

  8. Thrips transmission of tospoviruses.

    Science.gov (United States)

    Rotenberg, Dorith; Jacobson, Alana L; Schneweis, Derek J; Whitfield, Anna E

    2015-12-01

    One hundred years ago, the disease tomato spotted wilt was first described in Australia. Since that time, knowledge of this disease caused by Tomato spotted wilt virus (TSWV) and transmitted by thrips (insects in the order Thysanoptera) has revealed a complex relationship between the virus, vector, plant host, and environment. Numerous tospoviruses and thrips vectors have been described, revealing diversity in plant host range and geographical distributions. Advances in characterization of the tripartite interaction between the virus, vector, and plant host have provided insight into molecular and ecological relationships. Comparison to animal-infecting viruses in the family Bunyaviridae has enabled the identification of commonalities between tospoviruses and other bunyaviruses in transmission by arthropod vectors and molecular interactions with hosts. This review provides a special emphasis on TSWV and Frankliniella occidentalis, the model tospovirus-thrips pathosystem. However, other virus-vector combinations are also of importance and where possible, comparisons are made between different viruses and thrips vectors. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Haemorrhagic fevers and ecological perturbations.

    Science.gov (United States)

    Le Guenno, B

    1997-01-01

    Hemorrhagic fever is a clinical and imprecise definition for several different diseases. Their main common point is to be zoonoses. These diseases are due to several viruses which belong to different families. The Flaviviridae have been known for the longest time. They include the Amaril virus that causes yellow fever and is transported by mosquitoes. Viruses that have come to light more recently belong to three other families: Arenaviridae, Bunyaviridae, and Filoviridae. They are transmitted by rodents (hantaviruses and arenaviruses) or from unknown reservoirs (Ebola Marburg). The primary cause of most outbreaks of hemorrhagic fever viruses is ecological disruption resulting from human activities. The expansion of the world population perturbs ecosystems that were stable a few decades ago and facilitates contacts with animals carrying viruses pathogenic to humans. Another dangerous human activity is the development of hospitals with poor medical hygiene. Lassa, Crimean-Congo or Ebola outbreaks are mainly nosocomial. There are also natural environmental changes: the emergence of Sin Nombre in the U.S. resulted from heavier than usual rain and snow during spring 1993 in the Four Corners. Biological industries also present risks. In 1967, collection of organs from monkeys allowed the discovery in Marburg of a new family of viruses, the Filoviridae. Hemorrhagic fever viruses are cause for worry, and the avenues to reduce their toll are still limited.

  10. Serosurvey of Crimean-Congo Hemorrhagic Fever Virus in Cattle, Mali, West Africa.

    Science.gov (United States)

    Maiga, Ousmane; Sas, Miriam Andrada; Rosenke, Kyle; Kamissoko, Badian; Mertens, Marc; Sogoba, Nafomon; Traore, Abdallah; Sangare, Modibo; Niang, Mamadou; Schwan, Tom G; Maiga, Hamidou Moussa; Traore, Sekou F; Feldmann, Heinz; Safronetz, David; Groschup, Martin H

    2017-06-01

    AbstractCrimean-Congo hemorrhagic fever is a tick-borne disease caused by the arbovirus Crimean-Congo hemorrhagic fever virus (CCHFV, family Bunyaviridae, genus Nairovirus ). CCHFV can cause a severe hemorrhagic fever with high-case fatality rates in humans. CCHFV has a wide geographic range and has been described in around 30 countries in the Middle East, Asia, Europe, and Africa including Mali and neighboring countries. To date, little is known about the prevalence rates of CCHFV in Mali. Here, using banked bovine serum samples from across the country, we describe the results of a seroepidemiological study for CCHFV aimed at identifying regions of circulation in Mali. In total, 1,074 serum samples were tested by a modified in-house CCHFV-IgG-enzyme-linked immunosorbent assay (ELISA) with confirmatory testing by commercial ELISA and immunofluorescence assay. Overall, 66% of samples tested were positive for CCHFV-specific IgG antibodies. Regional seroprevalence rates ranged from 15% to 95% and seemed to correlate with cattle density. Our results demonstrate that CCHFV prevalence is high in many regions in Mali and suggest that CCHFV surveillance should be established.

  11. Severe fever with thrombocytopenia syndrome, an emerging tick-borne zoonosis.

    Science.gov (United States)

    Liu, Quan; He, Biao; Huang, Si-Yang; Wei, Feng; Zhu, Xing-Quan

    2014-08-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging haemorrhagic fever that was first described in rural areas of China. The causative agent, SFTS virus (SFTSV), is a novel phlebovirus in the Bunyaviridae family. Since the first report in 2010, SFTS has been found in 11 provinces of China, with about 2500 reported cases, and an average case-fatality rate of 7·3%. The disease was also reported in Japan and Korea in 2012; Heartland virus, another phlebovirus genetically closely related to SFTSV, was isolated from two patients in the USA. The disease has become a substantial risk to public health, not only in China, but also in other parts of the world. The virus could undergo rapid evolution by gene mutation, reassortment, and homologous recombination in tick vectors and vertebrate reservoir hosts. No specific treatment of SFTS is available, and avoiding tick bites is an important measure to prevent the infection and transmission of SFTSV. This Review provides information on the molecular characteristics and ecology of this emerging tick-borne virus and describes the epidemiology, clinical signs, pathogenesis, diagnosis, treatment, and prevention of human infection with SFTSV. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Evaluation of the efficacy of disinfectants against Puumala hantavirus by real-time RT-PCR.

    Science.gov (United States)

    Maes, Piet; Li, Sandra; Verbeeck, Jannick; Keyaerts, Els; Clement, Jan; Van Ranst, Marc

    2007-04-01

    Puumala virus, a hantavirus belonging to the Bunyaviridae family, causes a human disease known as nephropathia epidemica, a mild form of hemorrhagic fever with renal syndrome. The implementation of effective decontamination procedures is critical in hantavirus research to minimize the risk of personnel exposure. This study investigated the efficacy of Clidox((R)), Dettol((R)), ethanol, Halamid-d((R)), peracetic acid, sodium hypochloride and Virkon((R))S for inactivating Puumala virus. A real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to quantify Puumala virus before and after treatment with these products. Inactivation of Puumala virus was effective after 10min with all products except ethanol. Inactivation with absolute ethanol was effective only after 30min. Using the qRT-PCR method, this study has shown that the commercially available products Clidox((R)), Halamid-d((R)) and Virkon((R))S in particular represent a rapid and safe way to decontaminate surfaces with possible Puumala virus contamination. These products can be used in solutions of 1-2%, with contact times greater than 10min, for inactivating effectively Puumala virus.

  13. Roles of Host Species, Geographic Separation, and Isolation in the Seroprevalence of Jamestown Canyon and Snowshoe Hare Viruses in Newfoundland

    Science.gov (United States)

    Whitney, Hugh

    2012-01-01

    California serogroup viruses, including Jamestown Canyon virus (JCV) and snowshoe hare virus (SSHV), are mosquito-borne members of the Bunyaviridae family and are endemic across North America. These arboviruses are potential pathogens which occasionally cause neuroinvasive disease in humans and livestock. A neutralization assay was used to document JCV and SSHV seroprevalence using blood collected from a variety of domestic and wildlife host species. These species were sampled in an island setting, Newfoundland, which contains diverse ecoregions, ecological landscapes, and habitats. Seroprevalence rates for each virus differed significantly among host species and within certain species across different geographic areas. JCV was significantly associated with large mammals, and SSHV was significantly associated with snowshoe hares. Seroprevalence rates in the 5 species of animals tested for prior exposure to JCV ranged from 0% in snowshoe hares to 64% in horses. Seroprevalence rates for SSHV ranged from less than 1% in bovines to 55% in all snowshoe hares. The seroprevalence of SSHV differed significantly (P Newfoundland was associated with significantly lower JCV seroprevalence (P < 0.01) than that for cattle which had lived off-island. PMID:22798366

  14. Viral RNA Silencing Suppression: The Enigma of Bunyavirus NSs Proteins

    Directory of Open Access Journals (Sweden)

    Marcio Hedil

    2016-07-01

    Full Text Available The Bunyaviridae is a family of arboviruses including both plant- and vertebrate-infecting representatives. The Tospovirus genus accommodates plant-infecting bunyaviruses, which not only replicate in their plant host, but also in their insect thrips vector during persistent propagative transmission. For this reason, they are generally assumed to encounter antiviral RNA silencing in plants and insects. Here we present an overview on how tospovirus nonstructural NSs protein counteracts antiviral RNA silencing in plants and what is known so far in insects. Like tospoviruses, members of the related vertebrate-infecting bunyaviruses classified in the genera Orthobunyavirus, Hantavirus and Phlebovirus also code for a NSs protein. However, for none of them RNA silencing suppressor activity has been unambiguously demonstrated in neither vertebrate host nor arthropod vector. The second part of this review will briefly describe the role of these NSs proteins in modulation of innate immune responses in mammals and elaborate on a hypothetical scenario to explain if and how NSs proteins from vertebrate-infecting bunyaviruses affect RNA silencing. If so, why this discovery has been hampered so far.

  15. Diagnóstico virológico y molecular de virus transmitidos por roedores. Hantavirus y arenavirus

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    Silvana Levis

    2010-04-01

    Full Text Available Los hantavirus (familia Bunyaviridae y arenavirus (familia Arenaviridae son virus de roedores; cada uno de ellos parece estar estrictamente asociado con una especie de roedor en la que causa una infección persistente y asintomática. En las Américas tienen como reservorios primarios a roedores de la sub-familia Sigmodontinae, y son causantes de síndrome pulmonar por Hantavirus (SPH y fiebres hemorrágicas, respectivamente (1,2. El número de estos virus identificados en los últimos años ha aumentado significativamente; actualmente, el género Hantavirus está compuesto por más de 28 tipos diferentes, mientras que al menos 23 arenavirus conforman el género Arenavirus. Entre los hantavirus asociados con SPH se destacan el virus Sin Nombre en Norteamérica, y los virus Andes, Laguna Negra, Caño Delgadito, Araraquara y Juquitiba, en el cono sur de América, entre otros (2. Los arenavirus asociados a fiebres hemorrágicas reconocidos en Sud América al presente son: Junín (Argentina, Guanarito (Venezuela, Sabiá (Brasil, y Machupo y Chapare (Bolivia (3.

  16. Temperature-sensitive mutations for live-attenuated Rift Valley fever vaccines: Implications from other RNA viruses

    Directory of Open Access Journals (Sweden)

    Shoko eNishiyama

    2015-08-01

    Full Text Available Rift Valley fever (RVF is a mosquito-borne zoonotic disease endemic to the African continent. RVF is characterized by high rate of abortions in ruminants and hemorrhagic fever, encephalitis or blindness in humans. RVF is caused by the Rift Valley fever virus (RVFV: genus Phlebovirus, family Bunyaviridae. Vaccination is the only known effective strategy to prevent the disease, but there are no licensed RVF vaccines available for humans. A live-attenuated vaccine candidate derived from the wild-type pathogenic Egyptian ZH548 strain, MP-12, has been conditionally licensed for veterinary use in the United States. MP-12 displays a temperature-sensitive (ts phenotype and does not replicate at 41oC. The ts mutation limits viral replication at a specific body temperature and may lead to an attenuation of the virus. Here we will review well-characterized ts mutations for RNA viruses, and further discuss the potential in designing novel live-attenuated vaccines for RVF.

  17. Andes virus M genome segment is not sufficient to confer the virulence associated with Andes virus in Syrian hamsters.

    Science.gov (United States)

    McElroy, A K; Smith, J M; Hooper, J W; Schmaljohn, C S

    2004-08-15

    Sin Nombre virus (SNV) and Andes virus (ANDV), members of the genus Hantavirus, in the family Bunyaviridae, are causative agents of hantavirus pulmonary syndrome (HPS) in North and South America, respectively. Although ANDV causes a lethal HPS-like disease in hamsters, SNV, and all other HPS-associated hantaviruses that have been tested, cause asymptomatic infections of laboratory animals, including hamsters. In an effort to understand the pathogenicity of ANDV in the hamster model, we generated ANDV/SNV reassortant viruses. Plaque isolation of viruses from cell cultures infected with both parental viruses yielded only one type of stable reassortant virus: large (L) and small (S) segments of SNV and M segment of ANDV. This virus, designated SAS reassortant virus, had in vitro growth and plaque morphology characteristics similar to those of ANDV. When injected into hamsters, the SAS reassortant virus was highly infectious and elicited high-titer, ANDV-specific neutralizing antibodies; however, the virus did not cause HPS and was not lethal. These data indicate that the ANDV M genome segment is not sufficient to confer the lethal HPS phenotype associated with ANDV.

  18. Iquitos Virus: A Novel Reassortant Orthobunyavirus Associated with Human Illness in Peru

    Science.gov (United States)

    Aguilar, Patricia V.; Barrett, Alan D.; Saeed, Mohammad F.; Watts, Douglas M.; Russell, Kevin; Guevara, Carolina; Ampuero, Julia S.; Suarez, Luis; Cespedes, Manuel; Montgomery, Joel M.; Halsey, Eric S.; Kochel, Tadeusz J.

    2011-01-01

    Oropouche (ORO) virus, a member of the Simbu serogroup, is one of the few human pathogens in the Orthobunyavirus genus in the family Bunyaviridae. Genetic analyses of ORO-like strains from Iquitos, Peru, identified a novel reassortant containing the S and L segments of ORO virus and the M segment of a novel Simbu serogroup virus. This new pathogen, which we named Iquitos (IQT) virus, was first isolated during 1999 from a febrile patient in Iquitos, an Amazonian city in Peru. Subsequently, the virus was identified as the cause of outbreaks of “Oropouche fever” during 2005 and 2006 in Iquitos. In addition to the identification of 17 isolates of IQT virus between 1999 and 2006, surveys for neutralizing antibody among Iquitos residents revealed prevalence rates of 14.9% for ORO virus and 15.4% for IQT virus. Limited studies indicate that prior infection with ORO virus does not seem to protect against disease caused with the IQT virus infection. Identification of a new Orthobunyavirus human pathogen in the Amazon region of Peru highlights the need for strengthening surveillance activities and laboratory capabilities, and investigating the emergence of new pathogens in tropical regions of South America. PMID:21949892

  19. The partial sequence of RNA 1 of the ophiovirus Ranunculus white mottle virus indicates its relationship to rhabdoviruses and provides candidate primers for an ophiovirus-specific RT-PCR test.

    Science.gov (United States)

    Vaira, A M; Accotto, G P; Costantini, A; Milne, R G

    2003-06-01

    A 4018 nucleotide sequence was obtained for RNA 1 of Ranunculus white mottle virus (RWMV), genus Ophiovirus, representing an incomplete ORF of 1339 aa. Amino acid sequence analysis revealed significant similarities with RNA polymerases of viruses in the family Rhabdoviridae and a conserved domain of 685 aa, corresponding to the RdRp domain of those in the order Mononegavirales. Phylogenetic analysis indicated that the genus Ophiovirus is not related to the genus Tenuivirus or the family Bunyaviridae, with which it has been linked, and probably deserves a special taxonomic position, within a new family. A pair of degenerate primers was designed from a consensus sequence obtained from a relatively conserved region in the RNA 1 of two members of the genus, Citrus psorosis virus (CPsV) and RWMV. The primers, used in RT-PCR experiments, amplified a 136 bp DNA fragment from all the three recognized members of the genus, i.e. CPsV, RWMV and Tulip mild mottle mosaic virus (TMMMV) and from two tentative ophioviruses from lettuce and freesia. The amplified DNAs were sequenced and compared with the corresponding sequences of CPsV and RWMV and phylogenetic relationships were evaluated. Assays using extracts from plants infected by viruses belonging to the genera Tospovirus, Tenuivirus, Rhabdovirus and Varicosavirus indicated that the primers are genus-specific.

  20. Movement and nucleocapsid proteins coded by two tospovirus species interact through multiple binding regions in mixed infections.

    Science.gov (United States)

    Tripathi, Diwaker; Raikhy, Gaurav; Pappu, Hanu R

    2015-04-01

    Negative-stranded tospoviruses (family: Bunyaviridae) are among the most agronomically important viruses. Some of the tospoviruses are known to exist as mixed infections in the same host plant. Iris yellow spot virus (IYSV) and Tomato spotted wilt virus (TSWV) were used to study virus-virus interaction in dually infected host plants. Viral genes of both viruses were separately cloned into binary pSITE-BiFC vectors. BiFC results showed that the N and NSm proteins of IYSV interact with their counterparts coded by TSWV in dually infected Nicotiana benthamiana plants. BiFC results were further confirmed by pull down and yeast-2-hybrid (Y2H) assays. Interacting regions of the N and NSm proteins were also identified by Y2H system and β-galactosidase activity. Several regions of the N and NSm were found interacting with each other. The regions involved in these interactions are presumed to be critical for the functioning of the tospovirus N and NSm proteins. This is the first report of in vivo protein interactions of distinct tospoviruses in mixed infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. A mini-review of Bunyaviruses recorded in India

    Directory of Open Access Journals (Sweden)

    Pragya D Yadav

    2017-01-01

    Full Text Available Newly emerging and re-emerging viral infections are of major public health concern. Bunyaviridae family of viruses comprises a large group of animal viruses. Clinical symptoms exhibited by persons infected by viruses belonging to this family vary from mild-to-severe diseases i.e., febrile illness, encephalitis, haemorrhagic fever and acute respiratory illness. Several arthropods-borne viruses have been discovered and classified at serological level in India in the past. Some of these are highly pathogenic as the recent emergence and spread of Crimean-Congo haemorrhagic fever virus and presence of antibodies against Hantavirus in humans in India have provided evidences that it may become one of the emerging diseases in this country. For many of the discovered viruses, we still need to study their relevance to human and animal health. Chittoor virus, a variant of Batai virus; Ganjam virus, an Asian variant of Nairobi sheep disease virus; tick-borne viruses such as Bhanja, Palma and mosquito-borne viruses such as Sathuperi, Thimiri, Umbre and Ingwavuma viruses have been identified as the members of this family. As Bunyaviruses are three segmented RNA viruses, they can reassort the segments into genetically distinct viruses in target cells. This ability is believed to play a major role in evolution, pathogenesis and epidemiology of the viruses. Here, we provide a comprehensive overview of discovery, emergence and distribution of Bunyaviruses in India.

  2. Risk assessment of human infection with a novel bunyavirus in China

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    Tamano Matsui

    2012-11-01

    Full Text Available Objective: To assess the public health risk of human infection from a novel bunyavirus – severe fever with thrombocytopenia syndrome virus (SFTSV – in China.Methods: The likelihood of disease spread and the magnitude of public health impact were assessed to clarify overall risk. Literature about hazard, exposure and contextual factors associated with SFTSV infection was collected and reviewed. Information on SFTSV cases and the population in six provinces under surveillance was compared.Results: SFTSV is a member of the Phlebovirus genus of the Bunyaviridae family. A widely distributed tick species, Haemaphysalis longicornis, can act as the vector; thus the disease is likely to spread in China. Symptoms of SFTSV infection are nonspecific, but have led to multiorgan dysfunction in severe cases. High-risk populations include farmers and older females. Evidence of human-to-human transmission within family and hospital has been reported. The capacity for treatment and diagnosis of SFTSV are adequate in rural communities in China, and community awareness of the disease should be high. Discussion: There is a low to moderate public health risk related to SFTSV human infection in China. There is potential for an increase in the number of cases reported as awareness increases and when surveillance is expanded.

  3. [Inclusion Bodies are Formed in SFTSV-infected Human Macrophages].

    Science.gov (United States)

    Jin, Cong; Song, Jingdong; Han, Ying; Li, Chuan; Qiu, Peihong; Liang, Mifang

    2016-01-01

    The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.

  4. Evasion of Antiviral Immunity through Sequestering of TBK1/IKKε/IRF3 into Viral Inclusion Bodies

    Science.gov (United States)

    Wu, Xiaodong; Qi, Xian; Qu, Bingqian; Zhang, Zerui; Liang, Mifang; Li, Chuan; Cardona, Carol J.; Li, Dexin

    2014-01-01

    Cells are equipped with pattern recognition receptors (PRRs) such as the Toll-like and RIG-I-like receptors that mount innate defenses against viruses. However, viruses have evolved multiple strategies to evade or thwart host antiviral responses. Viral inclusion bodies (IBs), which are accumulated aggregates of viral proteins, are commonly formed during the replication of some viruses in infected cells, but their role in viral immune evasion has rarely been explored. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging febrile illness caused by a novel phlebovirus in the Bunyaviridae. The SFTS viral nonstructural protein NSs can suppress host beta interferon (IFN-β) responses. NSs can form IBs in infected and transfected cells. Through interaction with tank-binding kinase 1 (TBK1), viral NSs was able to sequester the IKK complex, including IKKε and IRF3, into IBs, although NSs did not interact with IKKε or IRF3 directly. When cells were infected with influenza A virus, IRF3 was phosphorylated and active phosphorylated IRF3 (p-IRF3) was translocated into the nucleus. In the presence of NSs, IRF3 could still be phosphorylated, but p-IRF3 was trapped in cytoplasmic IBs, resulting in reduced IFN-β induction and enhanced viral replication. Sequestration of the IKK complex and active IRF3 into viral IBs through the interaction of NSs and TBK1 is a novel mechanism for viral evasion of innate immunity. PMID:24335286

  5. Sequence and Structure Analysis of Distantly-Related Viruses Reveals Extensive Gene Transfer between Viruses and Hosts and among Viruses

    Science.gov (United States)

    Caprari, Silvia; Metzler, Saskia; Lengauer, Thomas; Kalinina, Olga V.

    2015-01-01

    The origin and evolution of viruses is a subject of ongoing debate. In this study, we provide a full account of the evolutionary relationships between proteins of significant sequence and structural similarity found in viruses that belong to different classes according to the Baltimore classification. We show that such proteins can be found in viruses from all Baltimore classes. For protein families that include these proteins, we observe two patterns of the taxonomic spread. In the first pattern, they can be found in a large number of viruses from all implicated Baltimore classes. In the other pattern, the instances of the corresponding protein in species from each Baltimore class are restricted to a few compact clades. Proteins with the first pattern of distribution are products of so-called viral hallmark genes reported previously. Additionally, this pattern is displayed by the envelope glycoproteins from Flaviviridae and Bunyaviridae and helicases of superfamilies 1 and 2 that have homologs in cellular organisms. The second pattern can often be explained by horizontal gene transfer from the host or between viruses, an example being Orthomyxoviridae and Coronaviridae hemagglutinin esterases. Another facet of horizontal gene transfer comprises multiple independent introduction events of genes from cellular organisms into otherwise unrelated viruses. PMID:26492264

  6. [Crimean-Congo hemorrhagic fever].

    Science.gov (United States)

    Saijo, Masayuki; Moriikawa, Shigeru; Kurane, Ichiro

    2004-12-01

    Crimean-Congo hemorrhagic fever (CCHF) is an acute infectious disease caused by CCHF virus (CCHFV), a member of the family Bunyaviridae, genus Nairovirus. The case fatality rate of CCHF ranges from 10-40%. Because CCHF is not present in Japan, many Japanese virologists and clinicians are not very familiar with this disease. However, there remains the possibility of an introduction of CCHFV or other hemorrhagic fever viruses into Japan from surrounding endemic areas. Development of diagnostic laboratory capacity for viral hemorrhagic fevers is necessary even in countries without these diseases. At the National Institute of Infectious Diseases, Tokyo, Japan, laboratory-based systems such as recombinant protein-based antibody detection, antigen-capture and pathological examination have been developed. In this review article, epidemiologic and clinical data on CCHF in the Xinjiang Uygur Autonomous Region, compiled through field investigations and diagnostic testing utilizing the aforementioned laboratory systems, are presented. CCHFV infections are closely associated with the environmental conditions, life styles, religion, occupation, and human economic activities. Based on these data, preventive measures for CCHFV infections are also discussed.

  7. Standardization of Immunoglobulin M Capture Enzyme-Linked Immunosorbent Assays for Routine Diagnosis of Arboviral Infections

    Science.gov (United States)

    Martin, Denise A.; Muth, David A.; Brown, Teresa; Johnson, Alison J.; Karabatsos, Nick; Roehrig, John T.

    2000-01-01

    Immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) is a rapid and versatile diagnostic method that readily permits the combination of multiple assays. Test consolidation is especially important for arthropod-borne viruses (arboviruses) which belong to at least three virus families: the Togaviridae, Flaviviridae, and Bunyaviridae. Using prototype viruses from each of these families and a panel of well-characterized human sera, we have evaluated and standardized a combined MAC-ELISA capable of identifying virus infections caused by members of each virus family. Furthermore, by grouping antigens geographically and utilizing known serological cross-reactivities, we have reduced the number of antigens necessary for testing, while maintaining adequate detection sensitivity. We have determined that a 1:400 serum dilution is most appropriate for screening antiviral antibody, using a positive-to-negative ratio of ≥2.0 as a positive cutoff value. With a blind-coded human serum panel, this combined MAC-ELISA was shown to have test sensitivity and specificity that correlated well with those of other serological techniques. PMID:10790107

  8. Gene S characterization of Hantavirus species Seoul virus isolated from Rattus norvegicuson an Indonesian island

    Directory of Open Access Journals (Sweden)

    Dian Perwitasari

    2014-08-01

    Full Text Available AbstrakLatar belakang: Hantavirus hidup dan berkembang biak di tubuh hewan pengerat, salah satunya Rattus norvegicus yang banyak ditemukan di daerah kepulauan di Indonesia. Hantavirus spesies Seoul virus (SEOV adalah virus RNA negatif rantai tunggal yang termasuk dalam keluarga Bunyaviridae, mempunyai beberapa gen spesifik terutama gen S yang dapat dikembangkan untuk uji diagnostik. Tujuan penelitian ini ialah untuk mengetahui karakter dari gen S dari Hantavirus spesies Seoulvirus.Metode:Pada penelitian ini dilakukan sekuensing gen S yang berasal dari jaringan paru-paru rodensia.  Fragmen DNA yang disekuensing menggunakan primer DNA SEOS-28F danSEOS -360R,VNS-1501F dan VNS-CSR. Hasil sekuensing dianalisis menggunakan program seqscapedan dianalisis menggunakan program Bioedit dan Mega5. Analisis filogenetik untuk homologi nukleotida dan asam amino dari ketiga strain Kepulauan Seribu tersebut dibandingkan dengan spesies hantavirus lainnya yang diambil dari genebank. Hasil:Analisis Homologi nukleotida dan asam amino antara strain Kepulauan Seribu dengan SEOV menunjukkan homologi nukleotida tertinggi pada strain KS74 (88,4% dan terendah pada KS90 (87,2%, sedangkan homologi asam amino tertinggi adalah strain KS74 (91.3% dan terendah pada strain KS90 (89,5%. Kesimpulan:Karakter gen S virus yang ditemukan di Kepulauan Seribu sebanding dengan virus SEOV yang ditemukan di Singapura dan Korea.  (Health Science Indones 2014;1:1-6Kata kunci:Seoul virus, gen S, Kepulauan Seribu, IndonesiaAbstractBackground: Hantavirus lives and reproduces in the body of rodents. Rattus norvegicuswas one found in the Kepulauan Seribu islands of Indonesia. Hantavirus species Seoul virus (SEOV is a negative single chain RNA viruses included in the family Bunyaviridae. It has a few specific genes, especially genes S that can be developed for a diagnostic test. The aim of this study was to ascertain the character of gene S of hantavirus species Seoul virus. Methods: Gene

  9. Anticuerpos frente a virus West nile y otros virus transmitidos por artropodos en la poblacion del Delta del Ebro

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    Lozano Alvaro

    1998-01-01

    Full Text Available FUNDAMENTOS: El virus West Nile (VWN es un Flavivirus que se transmite al hombre a través de distintas especies de mosquitos y produce brotes y casos esporádicos de enfermedad en distintas regiones del Viejo Mundo, incluída la Cuenca Mediterránea. Las zonas húmedas europeas que acogen aves migratorias procedentes de África constituyen áreas de alto riesgo para esta infección, así como para otras infecciones víricas transmitidas por artrópodos. MÉTODOS: Con objeto de investigar la prevalencia de la infección por el VWN y otros virus de transmisión similar en la población humana del Delta del Ebro, se estudiaron 1037 muestras de suero, obtenidas en 10 localidades de la zona, para presencia de anticuerpos frente a VWN y otros 12 virus transmitidos por artrópodos (3 Alfavirus, 8 Flaviviridae y 1 Bunyaviridae mediante titulación por inhibición de la hemaglutinación (IHA. En algunos casos se estudió la presencia de IgM específica por IHA tras fraccionar el suero por centrifugación en gradientes de sacarosa. RESULTADOS: En total, se encontró reactividad significativa frente a alguno de los virus probados en 130 casos (12.5%; 4.1% frente a Alfavirus, 8.0% frente a Flaviviridae y 0.4% frente a Bunyaviridae. El análisis de los títulos de anticuerpos reveló porcentajes significativos de muestras con títulos elevados frente a antígenos de VWN y otros. La distribución de la seroprevalencia fue muy desigual, concentrándose fundamentalmente en 3 localidades del interior del Delta (Ampolla, San Jaime y Montells, donde la prevalencia de anticuerpos frente a Flaviviridae llegó a alcanzar el 30% y se observaron niveles residuales de IgM frente a VWN en algunos sueros. CONCLUSIONES: Estos resultados y los obtenidos previamente en otras regiones de la Península Ibérica sugieren que el VWN circula en la población humana de las zonas de riesgo y produce brotes epidémicos periódicos. Habida cuenta del alto porcentaje de

  10. Epidemia de febre do Oropouche em Serra Pelada, município de Curionópolis, Pará, 1994

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    Amélia P.A.T. Rosa

    1996-12-01

    Full Text Available No final de novembro de 1994, o Instituto Evandro Chagas (IEC, Belém, Pará, foi notificado de um surto de doença febril na população do garimpo de Serra Pelada, município de Curionôpolis (5°35'S; 49°30'W, no Estado do Pará. Vinte amostras de soro de pessoas, com hemoscopia negativa para tnalária, foram recebidas para esclarecimento diagnóstico. Estudos laboratoriais comprovaram que os casos eram devido ao vírus Oropouche (grupo Simbu. gênero Bunyavirus, família Bunyaviridae. Esses achados, induziram d ida de um grupo de técnicos para realização de investigações ecoepidemíológicas entre 8 e 22 de dezembro. Foram coletadas 296 amostras de sangue, de 73 grupos familiares, sendo 54 para pequisa de vírus (casos febris e 242para sorologia, bem como, procedeu-se a coleta de artrópodes hematófagos. As amostras para pesquisa de vírus foram inoculadas em camundongos recém-nascidos e os soros testados por inibição da hemaglutinação (1H e MAC ELISA. Foram isoladas dez amostras do vírus Oropouche e obtidas seis soroconversões. Ademais, 245 (82,8% amostras foram positivas por sorologia e 71 (97,3% grupos familiares apresentaram pelo menos um membro positivo. Considerando a elevada positividade de anticoipos IH e IgM específica para Oropouche na população de Serra Pelada, concluímos que a epidemia foi extensa e apresentou taxa de ataque em torno de 83%, que correspondeu a infecção de cerca de 5.000 pessoas.In the final of November 1994, an outbreak of a febrile disease was observed in the Serra Pelada gold mine (5°35'S; 49°30'W in the Southeast region of Parã State. Twenty samples were collected and sent to the laboratory of Arbovirus of Instituto Evandro Chagas. The tests showed that the disease was caused by Oropouche virus (Bunyaviridae, Bunyavirus, Simbu serological group. Between 8-22 December 296 serum samples mere taken (54 from febrile patients, 16 paired samples and 242 from contacts and convalescent patients

  11. Unbiased RNA Shotgun Metagenomics in Social and Solitary Wild Bees Detects Associations with Eukaryote Parasites and New Viruses.

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    Karel Schoonvaere

    Full Text Available The diversity of eukaryote organisms and viruses associated with wild bees remains poorly characterized in contrast to the well-documented pathosphere of the western honey bee, Apis mellifera. Using a deliberate RNA shotgun metagenomic sequencing strategy in combination with a dedicated bioinformatics workflow, we identified the (micro-organisms and viruses associated with two bumble bee hosts, Bombus terrestris and Bombus pascuorum, and two solitary bee hosts, Osmia cornuta and Andrena vaga. Ion Torrent semiconductor sequencing generated approximately 3.8 million high quality reads. The most significant eukaryote associations were two protozoan, Apicystis bombi and Crithidia bombi, and one nematode parasite Sphaerularia bombi in bumble bees. The trypanosome protozoan C. bombi was also found in the solitary bee O. cornuta. Next to the identification of three honey bee viruses Black queen cell virus, Sacbrood virus and Varroa destructor virus-1 and four plant viruses, we describe two novel RNA viruses Scaldis River bee virus (SRBV and Ganda bee virus (GABV based on their partial genomic sequences. The novel viruses belong to the class of negative-sense RNA viruses, SRBV is related to the order Mononegavirales whereas GABV is related to the family Bunyaviridae. The potential biological role of both viruses in bees is discussed in the context of recent advances in the field of arthropod viruses. Further, fragmentary sequence evidence for other undescribed viruses is presented, among which a nudivirus in O. cornuta and an unclassified virus related to Chronic bee paralysis virus in B. terrestris. Our findings extend the current knowledge of wild bee parasites in general and addsto the growing evidence of unexplored arthropod viruses in valuable insects.

  12. Unbiased RNA Shotgun Metagenomics in Social and Solitary Wild Bees Detects Associations with Eukaryote Parasites and New Viruses.

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    Schoonvaere, Karel; De Smet, Lina; Smagghe, Guy; Vierstraete, Andy; Braeckman, Bart P; de Graaf, Dirk C

    2016-01-01

    The diversity of eukaryote organisms and viruses associated with wild bees remains poorly characterized in contrast to the well-documented pathosphere of the western honey bee, Apis mellifera. Using a deliberate RNA shotgun metagenomic sequencing strategy in combination with a dedicated bioinformatics workflow, we identified the (micro-)organisms and viruses associated with two bumble bee hosts, Bombus terrestris and Bombus pascuorum, and two solitary bee hosts, Osmia cornuta and Andrena vaga. Ion Torrent semiconductor sequencing generated approximately 3.8 million high quality reads. The most significant eukaryote associations were two protozoan, Apicystis bombi and Crithidia bombi, and one nematode parasite Sphaerularia bombi in bumble bees. The trypanosome protozoan C. bombi was also found in the solitary bee O. cornuta. Next to the identification of three honey bee viruses Black queen cell virus, Sacbrood virus and Varroa destructor virus-1 and four plant viruses, we describe two novel RNA viruses Scaldis River bee virus (SRBV) and Ganda bee virus (GABV) based on their partial genomic sequences. The novel viruses belong to the class of negative-sense RNA viruses, SRBV is related to the order Mononegavirales whereas GABV is related to the family Bunyaviridae. The potential biological role of both viruses in bees is discussed in the context of recent advances in the field of arthropod viruses. Further, fragmentary sequence evidence for other undescribed viruses is presented, among which a nudivirus in O. cornuta and an unclassified virus related to Chronic bee paralysis virus in B. terrestris. Our findings extend the current knowledge of wild bee parasites in general and addsto the growing evidence of unexplored arthropod viruses in valuable insects.

  13. Discovery of potent broad spectrum antivirals derived from marine actinobacteria.

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    Avi Raveh

    Full Text Available Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable

  14. Discovery of potent broad spectrum antivirals derived from marine actinobacteria.

    Science.gov (United States)

    Raveh, Avi; Delekta, Phillip C; Dobry, Craig J; Peng, Weiping; Schultz, Pamela J; Blakely, Pennelope K; Tai, Andrew W; Matainaho, Teatulohi; Irani, David N; Sherman, David H; Miller, David J

    2013-01-01

    Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable target for the

  15. Bovine Arboviruses in Culicoides Biting Midges and Sentinel Cattle in Southern Japan from 2003 to 2013.

    Science.gov (United States)

    Kato, T; Shirafuji, H; Tanaka, S; Sato, M; Yamakawa, M; Tsuda, T; Yanase, T

    2016-12-01

    Epizootic congenital abnormalities, encephalomyelitis and febrile illnesses in cattle caused by arthropod-borne viruses (arboviruses) are prevalent in Japan. Causative viruses including orthobunyaviruses, orbiviruses and rhabdovirus are thought to be transmitted by Culicoides biting midges. Recently, the incursions of several arboviruses, potentially Culicoides-borne, were newly confirmed in Japan. However, their spread pattern and exact vector species are currently uncertain. Attempts to isolate arboviruses from Culicoides biting midges and sentinel cattle were conducted in Kagoshima, located at the southernmost end of the main islands of Japan, a potentially high-risk area for incursion of arboviral diseases and outbreak of endemic ones. Seventy-eight isolates comprising Akabane, Peaton and Sathuperi viruses of the genus Orthobunyavirus of the family Bunyaviridae, bluetongue virus serotype 16, D'Aguilar virus, Bunyip Creek virus and epizootic haemorrhagic disease virus serotype 1 of the genus Orbivirus of the family Reoviridae, a potentially novel rhabdovirus of the genus Ephemerovirus and unidentified orbivirus-like viruses were obtained from Culicoides biting midges and sentinel cattle between 2003 and 2013. Akabane, Sathuperi, D'Aguilar and Bunyip Creek viruses were selectively isolated from Culicoides oxystoma, suggesting this vector's responsibility for these arbovirus outbreaks. The results of virus isolation also implied that C. tainanus, C. jacobsoni and C. punctatus are competent for the transmission of bluetongue virus serotype 16, Peaton virus and epizootic haemorrhagic disease virus serotype 1, respectively. Our monitoring in Culicoides biting midges and sentinel cattle detected the circulation of Akabane virus just prior to the accumulations of bovine congenital abnormalities and encephalomyelitis by it around study sites in 2003, 2006, 2008 and 2013. Silent circulations of the other arboviruses, including potentially new viruses, were also

  16. Ecology of the Tick-Borne Phlebovirus Causing Severe Fever with Thrombocytopenia Syndrome in an Endemic Area of China.

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    Zhifeng Li

    2016-04-01

    Full Text Available Severe fever with thrombocytopenia syndrome (SFTS is caused by SFTS virus (SFTSV, a tick-borne phlebovirus in family Bunyaviridae. Studies have found that humans, domestic and wildlife animals can be infected by SFTSV. However, the viral ecology, circulation, and transmission remain largely unknown.Sixty seven human SFTS cases were reported and confirmed by virus isolation or immunofluorescence assay between 2011 and 2014. In 2013-2014 we collected 9,984 ticks from either vegetation or small wild mammals in the endemic area in Jiangsu, China, and detected SFTSV-RNA by real-time RT-PCR in both questing and feeding Haemaphysalis longicornis and H. flava. Viral RNA was identified in larvae of H. longicornis prior to a first blood meal, which has never been confirmed previously in nature. SFTSV-RNA and antibodies were also detected by RT-PCR and ELISA, respectively, in wild mammals including Erinaceus europaeus and Sorex araneus. A live SFTSV was isolated from Erinaceus europaeus captured during the off tick-feeding season and with a high SFTSV antibody titer. Furthermore, SFTSV antibodies were detected in the migratory birds Anser cygnoides and Streptopelia chinensis using ELISA.The detection of SFTSV-RNA in non-engorged larvae indicated that vertical transmission of SFTSV in H. longicornis might occur in nature, which suggests that H. longicornis is a putative reservoir host of SFTSV. Small wild mammals such as Erinaceus europaeus and Sorex araneus could be infected by SFTSV and may serve as natural amplifying hosts. Our data unveiled that wild birds could be infected with SFTSV or carry SFTSV-infected ticks and thus might contribute to the long-distance spread of SFTSV via migratory flyways. These findings provide novel insights for understanding SFTSV ecology, reservoir hosts, and transmission in nature and will help develop new measures in preventing its rapid spread both regionally and globally.

  17. Ecology of the Tick-Borne Phlebovirus Causing Severe Fever with Thrombocytopenia Syndrome in an Endemic Area of China

    Science.gov (United States)

    Hu, Jianli; Liu, Wendong; Wang, Xiaochen; Zhang, Lei; Ji, Zhengmin; Feng, Zhi; Li, Luxun; Shen, Aihua; Liu, Xuejian; Zhao, Hongjun; Tan, Wenwen; Zhou, Jiangang; Qi, Xian; Zhu, Yefei; Tang, Fenyang; Cardona, Carol J.; Xing, Zheng

    2016-01-01

    Background Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a tick-borne phlebovirus in family Bunyaviridae. Studies have found that humans, domestic and wildlife animals can be infected by SFTSV. However, the viral ecology, circulation, and transmission remain largely unknown. Methodology/Principal Findings Sixty seven human SFTS cases were reported and confirmed by virus isolation or immunofluorescence assay between 2011 and 2014. In 2013–2014 we collected 9,984 ticks from either vegetation or small wild mammals in the endemic area in Jiangsu, China, and detected SFTSV-RNA by real-time RT-PCR in both questing and feeding Haemaphysalis longicornis and H. flava. Viral RNA was identified in larvae of H. longicornis prior to a first blood meal, which has never been confirmed previously in nature. SFTSV-RNA and antibodies were also detected by RT-PCR and ELISA, respectively, in wild mammals including Erinaceus europaeus and Sorex araneus. A live SFTSV was isolated from Erinaceus europaeus captured during the off tick-feeding season and with a high SFTSV antibody titer. Furthermore, SFTSV antibodies were detected in the migratory birds Anser cygnoides and Streptopelia chinensis using ELISA. Conclusions/Significance The detection of SFTSV-RNA in non-engorged larvae indicated that vertical transmission of SFTSV in H. longicornis might occur in nature, which suggests that H. longicornis is a putative reservoir host of SFTSV. Small wild mammals such as Erinaceus europaeus and Sorex araneus could be infected by SFTSV and may serve as natural amplifying hosts. Our data unveiled that wild birds could be infected with SFTSV or carry SFTSV-infected ticks and thus might contribute to the long-distance spread of SFTSV via migratory flyways. These findings provide novel insights for understanding SFTSV ecology, reservoir hosts, and transmission in nature and will help develop new measures in preventing its rapid spread both regionally and

  18. The native Wolbachia endosymbionts of Drosophila melanogaster and Culex quinquefasciatus increase host resistance to West Nile virus infection.

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    Robert L Glaser

    2010-08-01

    Full Text Available The bacterial endosymbiont Wolbachia pipientis has been shown to increase host resistance to viral infection in native Drosophila hosts and in the normally Wolbachia-free heterologous host Aedes aegypti when infected by Wolbachia from Drosophila melanogaster or Aedes albopictus. Wolbachia infection has not yet been demonstrated to increase viral resistance in a native Wolbachia-mosquito host system.In this study, we investigated Wolbachia-induced resistance to West Nile virus (WNV; Flaviviridae by measuring infection susceptibility in Wolbachia-infected and Wolbachia-free D. melanogaster and Culex quinquefasciatus, a natural mosquito vector of WNV. Wolbachia infection of D. melanogaster induces strong resistance to WNV infection. Wolbachia-infected flies had a 500-fold higher ID50 for WNV and produced 100,000-fold lower virus titers compared to flies lacking Wolbachia. The resistance phenotype was transmitted as a maternal, cytoplasmic factor and was fully reverted in flies cured of Wolbachia. Wolbachia infection had much less effect on the susceptibility of D. melanogaster to Chikungunya (Togaviridae and La Crosse (Bunyaviridae viruses. Wolbachia also induces resistance to WNV infection in Cx. quinquefasciatus. While Wolbachia had no effect on the overall rate of peroral infection by WNV, Wolbachia-infected mosquitoes produced lower virus titers and had 2 to 3-fold lower rates of virus transmission compared to mosquitoes lacking Wolbachia.This is the first demonstration that Wolbachia can increase resistance to arbovirus infection resulting in decreased virus transmission in a native Wolbachia-mosquito system. The results suggest that Wolbachia reduces vector competence in Cx. quinquefasciatus, and potentially in other Wolbachia-infected mosquito vectors.

  19. Planning for Rift Valley fever virus: use of geographical information systems to estimate the human health threat of white-tailed deer (Odocoileus virginianus)-related transmission.

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    Kakani, Sravan; LaBeaud, A Desirée; King, Charles H

    2010-11-01

    Rift Valley fever (RVF) virus is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt and the Arabian Peninsula. Based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from East Africa to neighbouring regions, RVF is considered a high-priority, emerging health threat for humans, livestock and wildlife in all parts of the world. Introduction of West Nile virus to North America has shown the potential for "exotic" viral pathogens to become embedded in local ecological systems. While RVF is known to infect and amplify within domestic livestock, such as taurine cattle, sheep and goats, if RVF virus is accidentally or intentionally introduced into North America, an important unknown factor will be the role of local wildlife in the maintenance or propagation of virus transmission. We examined the potential impact of RVF transmission via white-tailed deer (Odocoileus virginianus) in a typical north-eastern United States urban-suburban landscape, where livestock are rare but where these potentially susceptible, ungulate wildlife are highly abundant. Model results, based on overlap of mosquito, human and projected deer densities, indicate that a significant proportion (497/1186 km(2), i.e. 42%) of the urban and peri-urban landscape could be affected by RVF transmission during the late summer months. Deer population losses, either by intervention for herd reduction or by RVF-related mortality, would substantially reduce these likely transmission zones to 53.1 km(2), i.e. by 89%.

  20. Planning for Rift Valley fever virus: Use of GIS to estimate the human health threat of white-tailed deer (Odocoileus virginianus)-related transmission

    Science.gov (United States)

    Kakani, Sravan; LaBeaud, A. Desirée; King, Charles H.

    2011-01-01

    Rift Valley fever virus (RVFV) is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt,and the Arabian Peninsula. Based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from East Africa to neighboring regions, RVFV is considered a high-priority, emerging health threat forhumans, livestock, and wildlife in all parts of the world. Introduction of West Nile virus to North America has shown the potential for ‘exotic’ viral pathogens to become embedded in local ecological systems. While RVFV is known to infect and amplify within domestic livestock, such as taurine cattle, sheep, and goats, if RVFV is accidentally or intentionally introduced into North America, an important unknown factor will be the role of local wildlife in the maintenance or propagation of virus transmission. We examined the potential impact of RVFV transmission via white-tailed deer (Odocoileus virginianus)in a typical northeastern United States urban-suburban landscape, where livestock are rare, but these potentially susceptible ungulate wildlife are highly abundant. Model results, based on overlap of mosquito, human, and projected deer densities, indicate that a significant proportion (497/1186 km2, or 42 %) of the urban and peri-urban landscape could be affected by RVFV transmission during the late summermonths. Deer population losses, either by intervention for herd reduction or by RVFV-related mortality, would substantially reduce these likely transmission zones to 53.1 km2, orby 89%. PMID:21080319

  1. Crimean-Congo Hemorrhagic Fever Virus Glycoprotein Proteolytic Processing by Subtilase SKI-1

    Science.gov (United States)

    Vincent, Martin J.; Sanchez, Angela J.; Erickson, Bobbie R.; Basak, Ajoy; Chretien, Michel; Seidah, Nabil G.; Nichol, Stuart T.

    2003-01-01

    Crimean-Congo hemorrhagic fever (CCHF) virus is a tick-borne member of the genus Nairovirus, family Bunyaviridae. The mature virus glycoproteins, Gn and Gc (previously referred to as G2 and G1), are generated by proteolytic cleavage from precursor proteins. The amino termini of Gn and Gc are immediately preceded by tetrapeptides RRLL and RKPL, respectively, leading to the hypothesis that SKI-1 or related proteases may be involved (A. J. Sanchez, M. J. Vincent, and S. T. Nichol, J. Virol. 76:7263-7275, 2002). In vitro peptide cleavage data show that an RRLL peptide representing the Gn processing site is efficiently cleaved by SKI-1 protease, whereas an RKPL peptide representing the Gc processing site is cleaved at negligible levels. The efficient cleavage of RRLL peptide is consistent with the known recognition sequences of SKI-1, including the sequence determinants involved in the cleavage of the Lassa virus (family Arenaviridae) glycoprotein precursor. These in vitro findings were confirmed by expression of wild-type or mutant CCHF virus glycoproteins in CHO cells engineered to express functional or nonfunctional SKI-1. Gn processing was found to be dependent on functional SKI-1, whereas Gc processing was not. Gn processing occurred in the endoplasmic reticulum-cis Golgi compartments and was dependent on an R at the −4 position within the RRLL recognition motif, consistent with the known cleavage properties of SKI-1. Comparison of SKI-1 cleavage efficiency between peptides representing Lassa virus GP2 and CCHF virus Gn cleavage sites suggests that amino acids flanking the RRLL may modulate the efficiency. The apparent lack of SKI-1 cleavage at the CCHF virus Gc RKPL site indicates that related proteases, other than SKI-1, are likely to be involved in the processing at this site and identical or similar sites utilized in several New World arenaviruses. PMID:12885882

  2. Evolution of hantaviruses: co-speciation with reservoir hosts for more than 100 MYR.

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    Plyusnin, Alexander; Sironen, Tarja

    2014-07-17

    The most recent (9th) Report of the International Committee on Taxonomy of Viruses (ICTV) lists 23 established and 30 provisional species in the genus Hantavirus (family Bunyaviridae) (Plyusnin et al., 2012). These virus species are harbored by altogether 51 species of rodents, shrews and moles and thus in most cases it is a relationship of "one hantavirus-one host". Such a tight bond between the two, in combination with the observed association between whole groups of hantaviruses and (sub)families of rodents, helped to develop the widely accepted view of a long-term co-evolution (co-speciation) of these viruses with their hosts. Accumulating evidence of host-switching events, both recent and ancient, however challenged some of the earlier views on hantavirus evolution. In this paper we discuss the concept of hantavirus-host co-speciation and propose a scenario of hantavirus evolution based on the currently available genetic information. This scenario is based on the hypothesis that hantaviruses are very ancient viruses which already existed at the estimated diversification point of major placental clades, of which one includes the ancestors of the order Rodentia and another the ancestors of both orders Eulipotyphla and Chiroptera; the diversification occurred approximately at 90-100 MYA. We also speculate that the evolutionary history of hantaviruses extents even deeper in the past, beyond this time-point, and included the transmission of a (pre)bunyavirus from an insect host to a mammal host. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Landscape, Environmental and Social Predictors of Hantavirus Risk in São Paulo, Brazil.

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    Paula Ribeiro Prist

    Full Text Available Hantavirus Pulmonary Syndrome (HPS is a disease caused by Hantavirus, which are negative-sense RNA viruses in the family Bunyaviridae that are highly virulent to humans. Numerous factors modify risk of Hantavirus transmission and consequent HPS risk. Human-driven landscape change can foster transmission risk by increasing numbers of habitat generalist rodent species that serve as the principal reservoir host. Climate can also affect rodent population dynamics and Hantavirus survival, and a number of social factors can influence probability of HPS transmission to humans. Evaluating contributions of these factors to HPS risk may enable predictions of future outbreaks, and is critical to development of effective public health strategies. Here we rely on a Bayesian model to quantify associations between annual HPS incidence across the state of São Paulo, Brazil (1993-2012 and climate variables (annual precipitation, annual mean temperature, landscape structure metrics (proportion of native habitat cover, number of forest fragments, proportion of area planted with sugarcane, and social factors (number of men older than 14 years and Human Development Index. We built separate models for the main two biomes of the state (cerrado and Atlantic forest. In both biomes Hantavirus risk increased with proportion of land cultivated for sugarcane and HDI, but proportion of forest cover, annual mean temperature, and population at risk also showed positive relationships in the Atlantic forest. Our analysis provides the first evidence that social, landscape, and climate factors are associated with HPS incidence in the Neotropics. Our risk map can be used to support the adoption of preventive measures and optimize the allocation of resources to avoid disease propagation, especially in municipalities that show medium to high HPS risk (> 5% of risk, and aimed at sugarcane workers, minimizing the risk of future HPS outbreaks.

  4. Polar release of pathogenic Old World hantaviruses from renal tubular epithelial cells.

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    Krautkrämer, Ellen; Lehmann, Maik J; Bollinger, Vanessa; Zeier, Martin

    2012-11-30

    Epithelio- and endotheliotropic viruses often exert polarized entry and release that may be responsible for viral spread and dissemination. Hantaviruses, mostly rodent-borne members of the Bunyaviridae family infect epithelial and endothelial cells of different organs leading to organ dysfunction or even failure. Endothelial and renal epithelial cells belong to the target cells of Old World hantavirus. Therefore, we examined the release of hantaviruses in several renal epithelial cell culture models. We used Vero cells that are commonly used in hantavirus studies and primary human renal epithelial cells (HREpC). In addition, we analyzed MDCKII cells, an epithelial cell line of a dog kidney, which represents a widely accepted in vitro model of polarized monolayers for their permissiveness for hantavirus infection. Vero C1008 and primary HREpCs were grown on porous-support filter inserts for polarization. Monolayers were infected with hantavirus Hantaan (HTNV) and Puumala (PUUV) virus. Supernatants from the apical and basolateral chamber of infected cells were analyzed for the presence of infectious particles by re-infection of Vero cells. Viral antigen and infectious particles of HTNV and PUUV were exclusively detected in supernatants collected from the apical chamber of infected Vero C1008 cells and HREpCs. MDCKII cells were permissive for hantavirus infection and polarized MDCKII cells released infectious hantaviral particles from the apical surface corresponding to the results of Vero and primary human epithelial cells. Pathogenic Old World hantaviruses are released from the apical surface of different polarized renal epithelial cells. We characterized MDCKII cells as a suitable polarized cell culture model for hantavirus infection studies.

  5. C6/36 Aedes albopictus cells have a dysfunctional antiviral RNA interference response.

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    Doug E Brackney

    2010-10-01

    Full Text Available Mosquitoes rely on RNA interference (RNAi as their primary defense against viral infections. To this end, the combination of RNAi and invertebrate cell culture systems has become an invaluable tool in studying virus-vector interactions. Nevertheless, a recent study failed to detect an active RNAi response to West Nile virus (WNV infection in C6/36 (Aedes albopictus cells, a mosquito cell line frequently used to study arthropod-borne viruses (arboviruses. Therefore, we sought to determine if WNV actively evades the host's RNAi response or if C6/36 cells have a dysfunctional RNAi pathway. C6/36 and Drosophila melanogaster S2 cells were infected with WNV (Flaviviridae, Sindbis virus (SINV, Togaviridae and La Crosse virus (LACV, Bunyaviridae and total RNA recovered from cell lysates. Small RNA (sRNA libraries were constructed and subjected to high-throughput sequencing. In S2 cells, virus-derived small interfering RNAs (viRNAs from all three viruses were predominantly 21 nt in length, a hallmark of the RNAi pathway. However, in C6/36 cells, viRNAs were primarily 17 nt in length from WNV infected cells and 26-27 nt in length in SINV and LACV infected cells. Furthermore, the origin (positive or negative viral strand and distribution (position along viral genome of S2 cell generated viRNA populations was consistent with previously published studies, but the profile of sRNAs isolated from C6/36 cells was altered. In total, these results suggest that C6/36 cells lack a functional antiviral RNAi response. These findings are analogous to the type-I interferon deficiency described in Vero (African green monkey kidney cells and suggest that C6/36 cells may fail to accurately model mosquito-arbovirus interactions at the molecular level.

  6. Polar release of pathogenic Old World hantaviruses from renal tubular epithelial cells

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    Krautkrämer Ellen

    2012-11-01

    Full Text Available Abstract Background Epithelio- and endotheliotropic viruses often exert polarized entry and release that may be responsible for viral spread and dissemination. Hantaviruses, mostly rodent-borne members of the Bunyaviridae family infect epithelial and endothelial cells of different organs leading to organ dysfunction or even failure. Endothelial and renal epithelial cells belong to the target cells of Old World hantavirus. Therefore, we examined the release of hantaviruses in several renal epithelial cell culture models. We used Vero cells that are commonly used in hantavirus studies and primary human renal epithelial cells (HREpC. In addition, we analyzed MDCKII cells, an epithelial cell line of a dog kidney, which represents a widely accepted in vitro model of polarized monolayers for their permissiveness for hantavirus infection. Results Vero C1008 and primary HREpCs were grown on porous-support filter inserts for polarization. Monolayers were infected with hantavirus Hantaan (HTNV and Puumala (PUUV virus. Supernatants from the apical and basolateral chamber of infected cells were analyzed for the presence of infectious particles by re-infection of Vero cells. Viral antigen and infectious particles of HTNV and PUUV were exclusively detected in supernatants collected from the apical chamber of infected Vero C1008 cells and HREpCs. MDCKII cells were permissive for hantavirus infection and polarized MDCKII cells released infectious hantaviral particles from the apical surface corresponding to the results of Vero and primary human epithelial cells. Conclusions Pathogenic Old World hantaviruses are released from the apical surface of different polarized renal epithelial cells. We characterized MDCKII cells as a suitable polarized cell culture model for hantavirus infection studies.

  7. In search for factors that drive hantavirus epidemics.

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    Paul eHeyman

    2012-07-01

    Full Text Available In Europe, hantaviruses (Bunyaviridae are small mammal-associated zoonotic and emerging pathogens that can cause hemorrhagic fever with renal syndrome (HFRS. Puumala virus, the main etiological agent carried by the bank vole Myodes glareolus is responsible for a mild form of HFRS while Dobrava virus induces less frequent but more severe cases of HFRS.Since 2000 in Europe, more than 3000 cases of HFRS have been recorded, in average, each year, which is nearly double compared to the previous decade. In addition to this upside long-term trend, significant oscillations occur. Epidemic years appear, usually every 2-4 years, with an increased incidence, generally in localised hot spots. Moreover, the virus has been identified in new areas in the recent years.A great number of surveys have been carried out in order to assess the prevalence of the infection in the reservoir host and to identify links with different biotic and abiotic factors. The factors that drive the infections are related to the density and diversity of bank vole populations, prevalence of infection in the reservoir host, viral excretion in the environment, survival of the virus outside its host, and human behaviour, which affect the main transmission virus route through inhalation of infected rodent excreta..At the scale of a rodent population, the prevalence of the infection increases with the age of the individuals but also other parameters, such as sex and genetic variability, interfere. The contamination of the environment may be correlated to the number of newly infected rodents, which heavily excrete the virus. The interactions between these different parameters add to the complexity of the situation and explain the absence of reliable tools to predict epidemics. In this review, the factors that drive the epidemics of hantaviruses in Middle Europe are discussed through a panorama of the epidemiological situation in Belgium, France and Germany.

  8. Novel camelid antibody fragments targeting recombinant nucleoprotein of Araucaria hantavirus: a prototype for an early diagnosis of Hantavirus Pulmonary Syndrome.

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    Soraya S Pereira

    Full Text Available In addition to conventional antibodies, camelids produce immunoglobulins G composed exclusively of heavy chains in which the antigen binding site is formed only by single domains called VHH. Their particular characteristics make VHHs interesting tools for drug-delivery, passive immunotherapy and high-throughput diagnosis. Hantaviruses are rodent-borne viruses of the Bunyaviridae family. Two clinical forms of the infection are known. Hemorrhagic Fever with Renal Syndrome (HFRS is present in the Old World, while Hantavirus Pulmonary Syndrome (HPS is found on the American continent. There is no specific treatment for HPS and its diagnosis is carried out by molecular or serological techniques, using mainly monoclonal antibodies or hantavirus nucleoprotein (N to detect IgM and IgG in patient serum. This study proposes the use of camelid VHHs to develop alternative methods for diagnosing and confirming HPS. Phage display technology was employed to obtain VHHs. After immunizing one Lama glama against the recombinant N protein (prNΔ₈₅ of a Brazilian hantavirus strain, VHH regions were isolated to construct an immune library. VHHs were displayed fused to the M13KO7 phage coat protein III and the selection steps were performed on immobilized prNΔ₈₅. After selection, eighty clones recognized specifically the N protein. These were sequenced, grouped based mainly on the CDRs, and five clones were analyzed by western blot (WB, surface plasmon resonance (SPR device, and ELISA. Besides the ability to recognize prNΔ85 by WB, all selected clones showed affinity constants in the nanomolar range. Additionaly, the clone KC329705 is able to detect prNΔ₈₅ in solution, as well as the native viral antigen. Findings support the hypothesis that selected VHHs could be a powerful tool in the development of rapid and accurate HPS diagnostic assays, which are essential to provide supportive care to patients and reduce the high mortality rate associated with

  9. Seed Transmission of Soybean vein necrosis virus: The First Tospovirus Implicated in Seed Transmission.

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    Carol Groves

    Full Text Available Soybean vein necrosis virus (SVNV; genus Tospovirus; Family Bunyaviridae is a negative-sense single-stranded RNA virus that has been detected across the United States and in Ontario, Canada. In 2013, a seed lot of a commercial soybean variety (Glycine max with a high percentage of discolored, deformed and undersized seed was obtained. A random sample of this seed was planted in a growth room under standard conditions. Germination was greater than 90% and the resulting seedlings looked normal. Four composite samples of six plants each were tested by reverse transcription polymerase chain reaction (RT-PCR using published primers complimentary to the S genomic segment of SVNV. Two composite leaflet samples retrieved from seedlings yielded amplicons with a size and sequence predictive of SVNV. Additional testing of twelve arbitrarily selected individual plants resulted in the identification of two SVNV positive plants. Experiments were repeated by growing seedlings from the same seed lot in an isolated room inside a thrips-proof cage to further eliminate any external source of infection. Also, increased care was taken to reduce any possible PCR contamination. Three positive plants out of forty-eight were found using these measures. Published and newly designed primers for the L and M RNAs of SVNV were also used to test the extracted RNA and strengthen the diagnosis of viral infection. In experiments, by three scientists, in two different labs all three genomic RNAs of SVNV were amplified in these plant materials. RNA-seq analysis was also conducted using RNA extracted from a composite seedling sample found to be SVNV-positive and a symptomatic sample collected from the field. This analysis revealed both sense and anti-sense reads from all three gene segments in both samples. We have shown that SVNV can be transmitted in seed to seedlings from an infected seed lot at a rate of 6%. To our knowledge this is the first report of seed-transmission of a

  10. Incidence of thrips and tomato spotted wilt Tospovirus in fluecured tobacco protected from early season insect pest infestations.

    Science.gov (United States)

    McPherson, Robert M

    2006-06-01

    The relative impacts of early season thrips exclusion (cages) and thrips suppression (pesticides) on tomato spotted wilt (family Bunyaviridae, genus Tospovirus, TSW) Tospovirus infection in flue-cured tobacco, Nicotiana tobaccum L., were examined in field trials in 2001-2004. There were fewer TSW symptomatic plants when plants were covered by exclusion cages for 6 wk than when they were uncaged or caged for 2 or 4 wk after transplanting. Plant height, leaves per plant, and total leaf weight per plant were lower in TSW symptomatic plants compared with nonsymptomatic plants for the uncaged plus 2- and 4-wk caged duration treatments but not different when caged 6 wk. Weekly acephate (Orthene) foliar sprays for 2 or 4 wk after transplanting reduced thrips populations for up to 5 wk after transplanting, whereas the 6-wk sprays had lower thrips populations for up to 8 wk. TSW was lower in both the 4- and 6-wk acephate treatments than in the untreated. A tray drench application of imidacloprid (Admire) reduced thrips populations in early season plus lowered the percentage of TSW compared with no tray drench treatment. The tobacco thrips, Frankliniella fusca (Hinds), was the predominate thrips species on tobacco foliage, and 1.9-4.9% tested positive for nonstructural TSW protein. The imidacloprid tray drench treatment and 6-wk acephate foliar sprays had lower densities of the tobacco-adapted form of Myzus persicae (Sulzer). Suppressing early season thrips populations with foliar acephate or imidacloprid tray drench are management option that can effectively reduce the incidence of TSW in flue-cured tobacco plus suppress aphids.

  11. Role of insecticides in reducing thrips injury to plants and incidence of tomato spotted wilt virus in Virginia market-type peanut.

    Science.gov (United States)

    Herbert, D Ames; Malone, S; Aref, S; Brandenburg, R L; Jordan, D L; Royals, B M; Johnson, P D

    2007-08-01

    Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV), transmitted by many thrips species, is a devastating pathogen of peanut, Arachis hypogaea L. TSWV has become a serious problem in the Virginia/Carolina peanut-growing region of the United States. During 2002, TSWV was present in 47% of the North Carolina hectarage and caused a 5% yield reduction in Virginia. Factors influencing levels of TSWV in runner market-type peanut cultivars, which are primarily grown in Alabama, Flordia, Georgia, and Texas, have been integrated into an advisory to help those peanut growers reduce losses. An advisory based on the southeast runner market-type version is currently under development for virginia market-type peanut cultivars that are grown primarily in the Virginia/ Carolina region. A version based on preliminary field experiments was released in 2003. One factor used in both advisories relates to insecticide use to reduce the vector populations and disease incidence. This research elucidated the influence of insecticides on thrips populations, thrips plant injury, incidence of TSWV, and pod yield in virginia market-type peanut. Eight field trials from 2003 to 2005 were conducted at two locations. In-furrow application of aldicarb and phorate resulted in significant levels of thrips control, significant reductions in thrips injury to seedlings, reduced incidence of TSWV, and significant increases in pod yield. Foliar application of acephate after aldicarb or phorate applied in the seed furrow further reduced thrips plant injury and incidence of TSWV and improved yield. These findings will be used to improve the current virginia market-type TSWV advisory.

  12. Effects of Thrips Density, Mode of Inoculation, and Plant Age on Tomato Spotted Wilt Virus Transmission in Peanut Plants.

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    Shrestha, Anita; Sundaraj, Sivamani; Culbreath, Albert K; Riley, David G; Abney, Mark R; Srinivasan, Rajagopalbabu

    2015-02-01

    Spotted wilt caused by tomato spotted wilt virus (TSWV; family Bunyaviridae; genus Tospovirus) is a serious disease of peanut (Arachis hypogaea L.) in the southeastern United States. Peanut genotypes with field resistance to TSWV are effective in suppressing spotted wilt. All commercially available genotypes with field resistance to TSWV were developed through conventional breeding. As a part of the breeding process, peanut genotypes are regularly screened under field situations. Despite numerous advantages associated with field screening, it is often limited by inconsistent vector (thrips) and TSWV pressure. A greenhouse transmission protocol would aid in thorough screening of selected genotypes and conserve time. In this study, various parameters associated with TSWV transmission, including tobacco thrips, Frankliniella fusca (Hinds) density, mode of inoculation, and plant age, were evaluated. Greater incidences of TSWV infection were obtained with thrips-mediated inoculation when compared with mechanical inoculation. TSWV inoculation with three, five, and 10 thrips resulted in greater incidences of TSWV infection in plants than inoculation with one thrips. However, incidences of TSWV infection did not vary between plants inoculated with three, five, and 10 viruliferous thrips. With both thrips-mediated and mechanical inoculation methods, incidences of TSWV infection in 1-wk-old plants were greater than in 4-wk-old plants. TSWV copy numbers, as determined by qPCR, also decreased with plant age. Results suggest that using at least three thrips per plant and 1- to 2-wk-old plants would maximize TSWV infection in inoculated plants. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Characterization of bean necrotic mosaic virus: a member of a novel evolutionary lineage within the Genus Tospovirus.

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    de Oliveira, Athos Silva; Melo, Fernando Lucas; Inoue-Nagata, Alice Kazuko; Nagata, Tatsuya; Kitajima, Elliot Watanabe; Resende, Renato Oliveira

    2012-01-01

    Tospoviruses (Genus Tospovirus, Family Bunyaviridae) are phytopathogens responsible for significant worldwide crop losses. They have a tripartite negative and ambisense RNA genome segments, termed S (Small), M (Medium) and L (Large) RNA. The vector-transmission is mediated by thrips in a circulative-propagative manner. For new tospovirus species acceptance, several analyses are needed, e.g., the determination of the viral protein sequences for enlightenment of their evolutionary history. Biological (host range and symptomatology), serological, and molecular (S and M RNA sequencing and evolutionary studies) experiments were performed to characterize and differentiate a new tospovirus species, Bean necrotic mosaic virus (BeNMV), which naturally infects common beans in Brazil. Based upon the results, BeNMV can be classified as a novel species and, together with Soybean vein necrosis-associated virus (SVNaV), they represent members of a new evolutionary lineage within the genus Tospovirus. CONCLUSION/SIGNIFICANCES: Taken together, these evidences suggest that two divergent lineages of tospoviruses are circulating in the American continent and, based on the main clades diversity (American and Eurasian lineages), new tospovirus species related to the BeNMV-SVNaV clade remain to be discovered. This possible greater diversity of tospoviruses may be reflected in a higher number of crops as natural hosts, increasing the economic impact on agriculture. This idea also is supported since BeNMV and SVNaV were discovered naturally infecting atypical hosts (common bean and soybean, respectively), indicating, in this case, a preference for leguminous species. Further studies, for instance a survey focusing on crops, specifically of leguminous plants, may reveal a greater tospovirus diversity not only in the Americas (where both viruses were reported), but throughout the world.

  14. Characterization of bean necrotic mosaic virus: a member of a novel evolutionary lineage within the Genus Tospovirus.

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    Athos Silva de Oliveira

    Full Text Available BACKGROUND: Tospoviruses (Genus Tospovirus, Family Bunyaviridae are phytopathogens responsible for significant worldwide crop losses. They have a tripartite negative and ambisense RNA genome segments, termed S (Small, M (Medium and L (Large RNA. The vector-transmission is mediated by thrips in a circulative-propagative manner. For new tospovirus species acceptance, several analyses are needed, e.g., the determination of the viral protein sequences for enlightenment of their evolutionary history. METHODOLOGY/PRINCIPAL FINDINGS: Biological (host range and symptomatology, serological, and molecular (S and M RNA sequencing and evolutionary studies experiments were performed to characterize and differentiate a new tospovirus species, Bean necrotic mosaic virus (BeNMV, which naturally infects common beans in Brazil. Based upon the results, BeNMV can be classified as a novel species and, together with Soybean vein necrosis-associated virus (SVNaV, they represent members of a new evolutionary lineage within the genus Tospovirus. CONCLUSION/SIGNIFICANCES: Taken together, these evidences suggest that two divergent lineages of tospoviruses are circulating in the American continent and, based on the main clades diversity (American and Eurasian lineages, new tospovirus species related to the BeNMV-SVNaV clade remain to be discovered. This possible greater diversity of tospoviruses may be reflected in a higher number of crops as natural hosts, increasing the economic impact on agriculture. This idea also is supported since BeNMV and SVNaV were discovered naturally infecting atypical hosts (common bean and soybean, respectively, indicating, in this case, a preference for leguminous species. Further studies, for instance a survey focusing on crops, specifically of leguminous plants, may reveal a greater tospovirus diversity not only in the Americas (where both viruses were reported, but throughout the world.

  15. Seed Transmission of Soybean vein necrosis virus: The First Tospovirus Implicated in Seed Transmission.

    Science.gov (United States)

    Groves, Carol; German, Thomas; Dasgupta, Ranjit; Mueller, Daren; Smith, Damon L

    2016-01-01

    Soybean vein necrosis virus (SVNV; genus Tospovirus; Family Bunyaviridae) is a negative-sense single-stranded RNA virus that has been detected across the United States and in Ontario, Canada. In 2013, a seed lot of a commercial soybean variety (Glycine max) with a high percentage of discolored, deformed and undersized seed was obtained. A random sample of this seed was planted in a growth room under standard conditions. Germination was greater than 90% and the resulting seedlings looked normal. Four composite samples of six plants each were tested by reverse transcription polymerase chain reaction (RT-PCR) using published primers complimentary to the S genomic segment of SVNV. Two composite leaflet samples retrieved from seedlings yielded amplicons with a size and sequence predictive of SVNV. Additional testing of twelve arbitrarily selected individual plants resulted in the identification of two SVNV positive plants. Experiments were repeated by growing seedlings from the same seed lot in an isolated room inside a thrips-proof cage to further eliminate any external source of infection. Also, increased care was taken to reduce any possible PCR contamination. Three positive plants out of forty-eight were found using these measures. Published and newly designed primers for the L and M RNAs of SVNV were also used to test the extracted RNA and strengthen the diagnosis of viral infection. In experiments, by three scientists, in two different labs all three genomic RNAs of SVNV were amplified in these plant materials. RNA-seq analysis was also conducted using RNA extracted from a composite seedling sample found to be SVNV-positive and a symptomatic sample collected from the field. This analysis revealed both sense and anti-sense reads from all three gene segments in both samples. We have shown that SVNV can be transmitted in seed to seedlings from an infected seed lot at a rate of 6%. To our knowledge this is the first report of seed-transmission of a Tospovirus.

  16. Expression and characterization of a soluble form of tomato spotted wilt virus glycoprotein GN.

    Science.gov (United States)

    Whitfield, Anna E; Ullman, Diane E; German, Thomas L

    2004-12-01

    Tomato spotted wilt virus (TSWV), a member of the Tospovirus genus within the Bunyaviridae, is an economically important plant pathogen with a worldwide distribution. TSWV is transmitted to plants via thrips (Thysanoptera: Thripidae), which transmit the virus in a persistent propagative manner. The envelope glycoproteins, G(N) and G(C), are critical for the infection of thrips, but they are not required for the initial infection of plants. Thus, it is assumed that the envelope glycoproteins play important roles in the entry of TSWV into the insect midgut, the first site of infection. To directly test the hypothesis that G(N) plays a role in TSWV acquisition by thrips, we expressed and purified a soluble, recombinant form of the G(N) protein (G(N)-S). The expression of G(N)-S allowed us to examine the function of G(N) in the absence of other viral proteins. We detected specific binding to thrips midguts when purified G(N)-S was fed to thrips in an in vivo binding assay. The TSWV nucleocapsid protein and human cytomegalovirus glycoprotein B did not bind to thrips midguts, indicating that the G(N)-S-thrips midgut interaction is specific. TSWV acquisition inhibition assays revealed that thrips that were concomitantly fed purified TSWV and G(N)-S had reduced amounts of virus in their midguts compared to thrips that were fed TSWV only. Our findings that G(N)-S binds to larval thrips guts and decreases TSWV acquisition provide evidence that G(N) may serve as a viral ligand that mediates the attachment of TSWV to receptors displayed on the epithelial cells of the thrips midgut.

  17. Evaluation of onion cultivars for resistance to onion thrips (Thysanoptera: Thripidae) and Iris yellow spot virus.

    Science.gov (United States)

    Diaz-Montano, John; Fuchs, Marc; Nault, Brian A; Shelton, Anthony M

    2010-06-01

    Onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), a worldwide pest of onion, Allium cepa L., can reduce onion yield by > 50% and be even more problematic when it transmits Iris yellow spot virus (family Bunyaviridae, genus Tospovirus, IYSV). Because T. tabaci is difficult to control with insecticides and other strategies, field studies on onion, Allium cepa L., resistance to T. tabaci and IYSV were conducted in 2007 and 2008 in two locations in New York state. Forty-nine cultivars were evaluated for resistance by counting the number of larvae weekly and recording leaf damage. In another experiment, the impact of T. tabaci and IYSV on plant growth and yield was examined by spraying half of the plants with an insecticide. Eleven of the 49 cultivars had very little leaf damage and were considered resistant to T. tabaci. Visual assessment indicated that all resistant cultivars had yellow-green- colored foliage, whereas the other 38 had blue-green- colored foliage. The visual assessment of color agreed with data on color taken with a HunterLab Ultra Scan XE colorimeter. The onions 'Colorado 6' and 'NMSU 03-52-1' had the lowest numbers of T. tabaci, suggesting strong antibiosis and/or antixenosis. The other nine cultivars had variable numbers of T. tabaci, indicating a possible combination of categories of resistance. In the nonprotected treatments there were significant reductions in plant height and plant weight in most of the resistant cultivars, but there were reductions in bulb weight only in a few of them. The average of plants infected with IYSV was 10% in 2007 and 60% in 2008. Our findings indicate potential for developing onion resistance to T. tabaci as part of an overall integrated pest management strategy but suggest difficulties in identifying resistance to IYSV.

  18. Genetic Diversity of Crimean Congo Hemorrhagic Fever Virus Strains from Iran

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    Sadegh Chinikar

    2016-01-01

    Full Text Available Background: Crimean Congo hemorrhagic fever virus (CCHFV is a member of the Bunyaviridae family and Nairovirus genus. It has a negative-sense, single stranded RNA genome approximately 19.2 kb, containing the Small, Medium, and Large segments. CCHFVs are relatively divergent in their genome sequence and grouped in seven distinct clades based on S-segment sequence analysis and six clades based on M-segment sequences. Our aim was to obtain new insights into the molecular epidemiology of CCHFV in Iran.Methods: We analyzed partial and complete nucleotide sequences of the S and M segments derived from 50 Iranian patients. The extracted RNA was amplified using one-step RT-PCR and then sequenced. The sequences were ana­lyzed using Mega5 software.Results: Phylogenetic analysis of partial S segment sequences demonstrated that clade IV-(Asia 1, clade IV-(Asia 2 and clade V-(Europe accounted for 80 %, 4 % and 14 % of the circulating genomic variants of CCHFV in Iran respectively. However, one of the Iranian strains (Iran-Kerman/22 was associated with none of other sequences and formed a new clade (VII. The phylogenetic analysis of complete S-segment nucleotide sequences from selected Ira­nian CCHFV strains complemented with representative strains from GenBank revealed similar topology as partial sequences with eight major clusters. A partial M segment phylogeny positioned the Iranian strains in either associa­tion with clade III (Asia-Africa or clade V (Europe.Conclusion: The phylogenetic analysis revealed subtle links between distant geographic locations, which we pro­pose might originate either from international livestock trade or from long-distance carriage of CCHFV by infected ticks via bird migration.

  19. A Snapshot Avian Surveillance Reveals West Nile Virus and Evidence of Wild Birds Participating in Toscana Virus Circulation.

    Science.gov (United States)

    Hacioglu, Sabri; Dincer, Ender; Isler, Cafer Tayer; Karapinar, Zeynep; Ataseven, Veysel Soydal; Ozkul, Aykut; Ergunay, Koray

    2017-10-01

    Birds are involved in the epidemiology of several vector-borne viruses, as amplification hosts for viruses, dissemination vehicles for the vectors, and sources of emerging strains in cross-species transmission. Turkey provides diverse habitats for a variety of wild birds and is located along major bird migration routes. This study was undertaken to provide a cross-sectional screening of avian specimens for a spectrum of vector-borne viruses. The specimens were collected in Hatay province, in the Mediterranean coast of the Anatolian peninsula, located in the convergence zone of the known migration routes. Generic PCR assays were used for the detection of members of Nairovirus, Flavivirus, and Phlebovirus genera of Flaviviridae and Bunyaviridae families. The circulating viruses were characterized via sequencing and selected specimens were inoculated onto Vero cell lines for virus isolation. Specimens from 72 wild birds belonging in 8 orders and 14 species were collected. A total of 158 specimens that comprise 32 sera (20.3%) from 7 species and 126 tissues (79.7%) from 14 species were screened. Eight specimens (8/158, 5%), obtained from 4 individuals (4/72, 5.5%), were positive. West Nile virus (WNV) lineage 1 sequences were characterized in the spleen, heart, and kidney tissues from a lesser spotted eagle (Clanga pomarina), which distinctly clustered from sequences previously identified in Turkey. Toscana virus (TOSV) genotype A and B sequences were identified in brain and kidney tissues from a greater flamingo (Phoenicopterus roseus), a great white pelican (Pelecanus onocrotalus), and a black stork (Ciconia nigra), without successful virus isolation. Partial amino acid sequences of the viral nucleocapsid protein revealed previously unreported substitutions. This study documents the involvement of avians in WNV dispersion in Anatolia as well in TOSV life cycle.

  20. Epidemiological survey of Crimean Congo hemorrhagic fever virus in cattle in East Darfur State, Sudan.

    Science.gov (United States)

    Ibrahim, Alaa M; Adam, Ibrahim A; Osman, Badreldin T; Aradaib, Imadeldin E

    2015-06-01

    Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease caused by CCHF virus (CCHFV) of the genus Nairovirus in the family Bunyaviridae. CCHFV causes subclinical infection in domestic livestock and an often fatal hemorrhagic illness in humans, with approximately 30% mortality rates. In the present study, a cross-sectional serosurvey was conducted in a total of 282 randomly selected cattle from five localities in East Darfur State, Sudan. The exposure status to CCHF was determined using enzyme-linked immunosorbent assay (ELISA) for detection of CCHFV-specific IgG antibodies in cattle serum samples. The CCHFV-specific IgG antibodies were detected in 54 out of 282 animals, accounting for a 19.14% prevalence rate. Older cattle (>2 years of age) were approximately five times more likely to be infected with the virus (OR=4.90, CI=1.28-18.98, p-value=0.02). Heavily tick-infested cattle (ticks all over the body) were at 11 times higher at risk compared to tick-free animals (OR=11.11, CI=2.86-43.25, p-value=0.01). Grazing system is another factor affecting CCHF, where cattle grazing on open system were 27 times more at risk compared to other grazing systems (OR=27.22, CI=7.46-99.24, p-value=0.001). There was an association between localities and CCHF cattle (OR=0.24, CI=0.07-0.83, p-value=0.02). This study confirms the exposure of cattle to CCHF in East Darfur and identifies potential risk factors associated with the disease. Further epidemiological studies and improved surveillance are urgently needed to prevent a possible outbreak of CCHF among humans in the Darfur region of Sudan. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. Structure of the Leanyer orthobunyavirus nucleoprotein-RNA complex reveals unique architecture for RNA encapsidation.

    Science.gov (United States)

    Niu, Fengfeng; Shaw, Neil; Wang, Yao E; Jiao, Lianying; Ding, Wei; Li, Xiaomin; Zhu, Ping; Upur, Halmurat; Ouyang, Songying; Cheng, Genhong; Liu, Zhi-Jie

    2013-05-28

    Negative-stranded RNA viruses cover their genome with nucleoprotein (N) to protect it from the human innate immune system. Abrogation of the function of N offers a unique opportunity to combat the spread of the viruses. Here, we describe a unique fold of N from Leanyer virus (LEAV, Orthobunyavirus genus, Bunyaviridae family) in complex with single-stranded RNA refined to 2.78 Å resolution as well as a 2.68 Å resolution structure of LEAV N-ssDNA complex. LEAV N is made up of an N- and a C-terminal lobe, with the RNA binding site located at the junction of these lobes. The LEAV N tetramer binds a 44-nucleotide-long single-stranded RNA chain. Hence, oligomerization of N is essential for encapsidation of the entire genome and is accomplished by using extensions at the N and C terminus. Molecular details of the oligomerization of N are illustrated in the structure where a circular ring-like tertiary assembly of a tetramer of LEAV N is observed tethering the RNA in a positively charged cavity running along the inner edge. Hydrogen bonds between N and the C2 hydroxyl group of ribose sugar explain the specificity of LEAV N for RNA over DNA. In addition, base-specific hydrogen bonds suggest that some regions of RNA bind N more tightly than others. Hinge movements around F20 and V125 assist in the reversal of capsidation during transcription and replication of the virus. Electron microscopic images of the ribonucleoprotein complexes of LEAV N reveal a filamentous assembly similar to those found in phleboviruses.

  2. Complementation between two tospoviruses facilitates the systemic movement of a plant virus silencing suppressor in an otherwise restrictive host.

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    Sudeep Bag

    experimental evidence of functional complementation between two distinct tospoviruses in the Bunyaviridae family.

  3. Complementation between Two Tospoviruses Facilitates the Systemic Movement of a Plant Virus Silencing Suppressor in an Otherwise Restrictive Host

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    Eid, Sahar; Pappu, Hanu R.

    2012-01-01

    functional complementation between two distinct tospoviruses in the Bunyaviridae family. PMID:23077485

  4. First international external quality assessment of molecular detection of Crimean-Congo hemorrhagic fever virus.

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    Camille Escadafal

    Full Text Available Crimean-Congo hemorrhagic fever (CCHF is a zoonosis caused by a Nairovirus of the family Bunyaviridae. Infection is transmitted to humans mostly by Hyalomma ticks and also by direct contact with the blood or tissues of infected humans or viremic livestock. Clinical features usually include a rapid progression characterized by hemorrhage, myalgia and fever, with a lethality rate up to 30%. CCHF is one of the most widely distributed viral hemorrhagic fevers and has been reported in Africa, the Middle East and Asia, as well as parts of Europe. There is no approved vaccine or specific treatment against CCHF virus (CCHFV infections. In this context, an accurate diagnosis as well as a reliable surveillance of CCHFV infections is essential. Diagnostic techniques include virus culture, serology and molecular methods, which are now increasingly used. The European Network for the Diagnostics of "Imported" Viral Diseases organized the first international external quality assessment of CCHVF molecular diagnostics in 2011 to assess the efficiency and accurateness of CCHFV molecular methods applied by expert laboratories. A proficiency test panel of 15 samples was distributed to the participants including 10 different CCHFV preparations generated from infected cell cultures, a preparation of plasmid cloned with the nucleoprotein of CCHFV, two CCHFV RNA preparations and two negative controls. Forty-four laboratories worldwide participated in the EQA study and 53 data sets were received. Twenty data sets (38% met all criteria with optimal performance, 10 (19% with acceptable performance, while 23 (43% reported results showing a need for improvement. Differences in performance depended on the method used, the type of strain tested, the concentration of the sample tested and the laboratory performing the test. These results indicate that there is still a need for improving testing conditions and standardizing protocols for the molecular detection of Crimean

  5. Structural Analysis of Monomeric RNA-Dependent Polymerases: Evolutionary and Therapeutic Implications.

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    Rodrigo Jácome

    Full Text Available The crystal structures of monomeric RNA-dependent RNA polymerases and reverse transcriptases of more than 20 different viruses are available in the Protein Data Bank. They all share the characteristic right-hand shape of DNA- and RNA polymerases formed by the fingers, palm and thumb subdomains, and, in many cases, "fingertips" that extend from the fingers towards the thumb subdomain, giving the viral enzyme a closed right-hand appearance. Six conserved structural motifs that contain key residues for the proper functioning of the enzyme have been identified in all these RNA-dependent polymerases. These enzymes share a two divalent metal-ion mechanism of polymerization in which two conserved aspartate residues coordinate the interactions with the metal ions to catalyze the nucleotidyl transfer reaction. The recent availability of crystal structures of polymerases of the Orthomyxoviridae and Bunyaviridae families allowed us to make pairwise comparisons of the tertiary structures of polymerases belonging to the four main RNA viral groups, which has led to a phylogenetic tree in which single-stranded negative RNA viral polymerases have been included for the first time. This has also allowed us to use a homology-based structural prediction approach to develop a general three-dimensional model of the Ebola virus RNA-dependent RNA polymerase. Our model includes several of the conserved structural motifs and residues described in other viral RNA-dependent RNA polymerases that define the catalytic and highly conserved palm subdomain, as well as portions of the fingers and thumb subdomains. The results presented here help to understand the current use and apparent success of antivirals, i.e. Brincidofovir, Lamivudine and Favipiravir, originally aimed at other types of polymerases, to counteract the Ebola virus infection.

  6. Planning for Rift Valley fever virus: use of geographical information systems to estimate the human health threat of white-tailed deer (Odocoileus virginianus-related transmission

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    Sravan Kakani

    2010-11-01

    Full Text Available Rift Valley fever (RVF virus is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt and the Arabian Peninsula. Based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from East Africa to neighbouring regions, RVF is considered a high-priority, emerging health threat for humans, livestock and wildlife in all parts of the world. Introduction of West Nile virus to North America has shown the potential for “exotic” viral pathogens to become embedded in local ecological systems. While RVF is known to infect and amplify within domestic livestock, such as taurine cattle, sheep and goats, if RVF virus is accidentally or intentionally introduced into North America, an important unknown factor will be the role of local wildlife in the maintenance or propagation of virus transmission. We examined the potential impact of RVF transmission via white-tailed deer (Odocoileus virginianus in a typical north-eastern United States urban-suburban landscape, where livestock are rare but where these potentially susceptible, ungulate wildlife are highly abundant. Model results, based on overlap of mosquito, human and projected deer densities, indicate that a significant proportion (497/1186 km2, i.e. 42% of the urban and peri-urban landscape could be affected by RVF transmission during the late summer months. Deer population losses, either by intervention for herd reduction or by RVF-related mortality, would substantially reduce these likely transmission zones to 53.1 km2, i.e. by 89%.

  7. Mosquito-borne Inkoo virus in northern Sweden - isolation and whole genome sequencing.

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    Lwande, Olivia Wesula; Bucht, Göran; Ahlm, Clas; Ahlm, Kristoffer; Näslund, Jonas; Evander, Magnus

    2017-03-23

    Inkoo virus (INKV) is a less known mosquito-borne virus belonging to Bunyaviridae, genus Orthobunyavirus, California serogroup. Studies indicate that INKV infection is mainly asymptomatic, but can cause mild encephalitis in humans. In northern Europe, the sero-prevalence against INKV is high, 41% in Sweden and 51% in Finland. Previously, INKV RNA has been detected in adult Aedes (Ae.) communis, Ae. hexodontus and Ae. punctor mosquitoes and Ae. communis larvae, but there are still gaps of knowledge regarding mosquito vectors and genetic diversity. Therefore, we aimed to determine the occurrence of INKV in its mosquito vector and characterize the isolates. About 125,000 mosquitoes were collected during a mosquito-borne virus surveillance in northern Sweden during the summer period of 2015. Of these, 10,000 mosquitoes were processed for virus isolation and detection using cell culture and RT-PCR. Virus isolates were further characterized by whole genome sequencing. Genetic typing of mosquito species was conducted by cytochrome oxidase subunit I (COI) gene amplification and sequencing (genetic barcoding). Several Ae. communis mosquitoes were found positive for INKV RNA and two isolates were obtained. The first complete sequences of the small (S), medium (M), and large (L) segments of INKV in Sweden were obtained. Phylogenetic analysis showed that the INKV genome was most closely related to other INKV isolates from Sweden and Finland. Of the three INKV genome segments, the INKV M segment had the highest frequency of non-synonymous mutations. The overall G/C-content of INKV genes was low for the N/NSs genes (43.8-45.5%), polyprotein (Gn/Gc/NSm) gene (35.6%) and the RNA polymerase gene (33.8%) This may be due to the fact that INKV in most instances utilized A or T in the third codon position. INKV is frequently circulating in northern Sweden and Ae. communis is the key vector. The high mutation rate of the INKV M segment may have consequences on virulence.

  8. Genetic Diversity and Reassortment of Hantaan Virus Tripartite RNA Genomes in Nature, the Republic of Korea.

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    Jeong-Ah Kim

    2016-06-01

    Full Text Available Hantaan virus (HTNV, a negative sense tripartite RNA virus of the Family Bunyaviridae, is the most prevalent hantavirus in the Republic of Korea (ROK. It is the causative agent of Hemorrhagic Fever with Renal Syndrome (HFRS in humans and maintained in the striped field mouse, Apodemus agrarius, the primary zoonotic host. Clinical HFRS cases have been reported commonly in HFRS-endemic areas of Gyeonggi province. Recently, the death of a member of the ROK military from Gangwon province due to HFRS prompted an investigation of the epidemiology and distribution of hantaviruses in Gangwon and Gyeonggi provinces that border the demilitarized zone separating North and South Korea.To elucidate the geographic distribution and molecular diversity of HTNV, whole genome sequences of HTNV Large (L, Medium (M, and Small (S segments were acquired from lung tissues of A. agrarius captured from 2003-2014. Consistent with the clinical incidence of HFRS established by the Korea Centers for Disease Control & Prevention (KCDC, the prevalence of HTNV in naturally infected mice in Gangwon province was lower than for Gyeonggi province. Whole genomic sequences of 34 HTNV strains were identified and a phylogenetic analysis showed geographic diversity of the virus in the limited areas. Reassortment analysis first suggested an occurrence of genetic exchange of HTNV genomes in nature, ROK.This study is the first report to demonstrate the molecular prevalence of HTNV in Gangwon province. Whole genome sequencing of HTNV showed well-supported geographic lineages and the molecular diversity in the northern region of ROK due to a natural reassortment of HTNV genomes. These observations contribute to a better understanding of the genetic diversity and molecular evolution of hantaviruses. Also, the full-length of HTNV tripartite genomes will provide a database for phylogeographic analysis of spatial and temporal outbreaks of hantavirus infection.

  9. Complementation between two tospoviruses facilitates the systemic movement of a plant virus silencing suppressor in an otherwise restrictive host.

    Science.gov (United States)

    Bag, Sudeep; Mitter, Neena; Eid, Sahar; Pappu, Hanu R

    2012-01-01

    Bunyaviridae family.

  10. Purple coneflower viruses: species diversity and harmfulness

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    Dunich A. A.

    2015-02-01

    Full Text Available Viral diseases became an actual problem in medicinal plants cultivation. The number of viruses known to infect purple coneflower increased significantly in the last years in many countries. However, there is no any review about the viral diseases of this valuable medicinal crop. Therefore, the aim of this article is to summarize the main information about the viruses affecting purple coneflower plants (Echinacea purpurea L. Moench.. An analysis of the literature data showed that purple coneflower could be infected by 10 viruses. These viruses belong to the families Bromoviridae, Bunyaviridae, Secoviridae, Potyviridae, Vir­ga­vi­ri­dae, and almost all of them are considered to be highly harmful plant viruses. Additionally, four of them (TMV, TSWV, CMV, PVY are in the top 10 of the most economically important plant viruses in the world and occupy the first places. Such distribution and harmfulness of these viruses are explained by a wide range of sensitive host-plants, wild plants and weeds – reservoirs of an infection, and also a large number of vectors. The data from a few countries show that the viral diseases of purple coneflower are becoming more severe from year to year. The appearance of new viruses is registered on coneflower every year that complicates prognosis and risk estimation of epiphytoties in these regions which, for example, were revealed in Bulgaria, Lithuania and Ukraine. This review presents the detailed symptoms of the viral diseases in purple coneflower, the main properties of each virus and data about their harmful effect on the quality of raw material (the concentration of biologically active substances and heavy metals in plants.

  11. Small RNA Profiling in Dengue Virus 2-Infected Aedes Mosquito Cells Reveals Viral piRNAs and Novel Host miRNAs.

    Science.gov (United States)

    Miesen, Pascal; Ivens, Alasdair; Buck, Amy H; van Rij, Ronald P

    2016-02-01

    In Aedes mosquitoes, infections with arthropod-borne viruses (arboviruses) trigger or modulate the expression of various classes of viral and host-derived small RNAs, including small interfering RNAs (siRNAs), PIWI interacting RNAs (piRNAs), and microRNAs (miRNAs). Viral siRNAs are at the core of the antiviral RNA interference machinery, one of the key pathways that limit virus replication in invertebrates. Besides siRNAs, Aedes mosquitoes and cells derived from these insects produce arbovirus-derived piRNAs, the best studied examples being viruses from the Togaviridae or Bunyaviridae families. Host miRNAs modulate the expression of a large number of genes and their levels may change in response to viral infections. In addition, some viruses, mostly with a DNA genome, express their own miRNAs to regulate host and viral gene expression. Here, we perform a comprehensive analysis of both viral and host-derived small RNAs in Aedes aegypti Aag2 cells infected with dengue virus 2 (DENV), a member of the Flaviviridae family. Aag2 cells are competent in producing all three types of small RNAs and provide a powerful tool to explore the crosstalk between arboviral infection and the distinct RNA silencing pathways. Interestingly, besides the well-characterized DENV-derived siRNAs, a specific population of viral piRNAs was identified in infected Aag2 cells. Knockdown of Piwi5, Ago3 and, to a lesser extent, Piwi6 results in reduction of vpiRNA levels, providing the first genetic evidence that Aedes PIWI proteins produce DENV-derived small RNAs. In contrast, we do not find convincing evidence for the production of virus-derived miRNAs. Neither do we find that host miRNA expression is strongly changed upon DENV2 infection. Finally, our deep-sequencing analyses detect 30 novel Aedes miRNAs, complementing the repertoire of regulatory small RNAs in this important vector species.

  12. Differential Antagonism of Human Innate Immune Responses by Tick-Borne Phlebovirus Nonstructural Proteins.

    Science.gov (United States)

    Rezelj, Veronica V; Li, Ping; Chaudhary, Vidyanath; Elliott, Richard M; Jin, Dong-Yan; Brennan, Benjamin

    2017-01-01

    In recent years, several newly discovered tick-borne viruses causing a wide spectrum of diseases in humans have been ascribed to the Phlebovirus genus of the Bunyaviridae family. The nonstructural protein (NSs) of bunyaviruses is the main virulence factor and interferon (IFN) antagonist. We studied the molecular mechanisms of IFN antagonism employed by the NSs proteins of human apathogenic Uukuniemi virus (UUKV) and those of Heartland virus (HRTV) and severe fever with thrombocytopenia syndrome virus (SFTSV), both of which cause severe disease. Using reporter assays, we found that UUKV NSs weakly inhibited the activation of the beta interferon (IFN-β) promoter and response elements. UUKV NSs weakly antagonized human IFN-β promoter activation through a novel interaction with mitochondrial antiviral-signaling protein (MAVS), confirmed by coimmunoprecipitation and confocal microscopy studies. HRTV NSs efficiently antagonized both IFN-β promoter activation and type I IFN signaling pathways through interactions with TBK1, preventing its phosphorylation. HRTV NSs exhibited diffused cytoplasmic localization. This is in comparison to the inclusion bodies formed by SFTSV NSs. HRTV NSs also efficiently interacted with STAT2 and impaired IFN-β-induced phosphorylation but did not affect STAT1 or its translocation to the nucleus. Our results suggest that a weak interaction between STAT1 and HRTV or SFTSV NSs may explain their inability to block type II IFN signaling efficiently, thus enabling the activation of proinflammatory responses that lead to severe disease. Our findings offer insights into how pathogenicity may be linked to the capacity of NSs proteins to block the innate immune system and illustrate the plethora of viral immune evasion strategies utilized by emerging phleboviruses. IMPORTANCE Since 2011, there has been a large expansion in the number of emerging tick-borne viruses that have been assigned to the Phlebovirus genus. Heartland virus (HRTV) and SFTS

  13. Functional analysis of Rift Valley fever virus NSs encoding a partial truncation.

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    Jennifer A Head

    Full Text Available Rift Valley fever virus (RVFV, belongs to genus Phlebovirus of the family Bunyaviridae, causes high rates of abortion and fetal malformation in infected ruminants as well as causing neurological disorders, blindness, or lethal hemorrhagic fever in humans. RVFV is classified as a category A priority pathogen and a select agent in the U.S., and currently there are no therapeutics available for RVF patients. NSs protein, a major virulence factor of RVFV, inhibits host transcription including interferon (IFN-β mRNA synthesis and promotes degradation of dsRNA-dependent protein kinase (PKR. NSs self-associates at the C-terminus 17 aa., while NSs at aa.210-230 binds to Sin3A-associated protein (SAP30 to inhibit the activation of IFN-β promoter. Thus, we hypothesize that NSs function(s can be abolished by truncation of specific domains, and co-expression of nonfunctional NSs with intact NSs will result in the attenuation of NSs function by dominant-negative effect. Unexpectedly, we found that RVFV NSs truncated at aa. 6-30, 31-55, 56-80, 81-105, 106-130, 131-155, 156-180, 181-205, 206-230, 231-248 or 249-265 lack functions of IFN-β mRNA synthesis inhibition and degradation of PKR. Truncated NSs were less stable in infected cells, while nuclear localization was inhibited in NSs lacking either of aa.81-105, 106-130, 131-155, 156-180, 181-205, 206-230 or 231-248. Furthermore, none of truncated NSs had exhibited significant dominant-negative functions for NSs-mediated IFN-β suppression or PKR degradation upon co-expression in cells infected with RVFV. We also found that any of truncated NSs except for intact NSs does not interact with RVFV NSs even in the presence of intact C-terminus self-association domain. Our results suggest that conformational integrity of NSs is important for the stability, cellular localization and biological functions of RVFV NSs, and the co-expression of truncated NSs does not exhibit dominant-negative phenotype.

  14. Characterization of Rift Valley fever virus MP-12 strain encoding NSs of Punta Toro virus or sandfly fever Sicilian virus.

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    Olga A Lihoradova

    Full Text Available Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is attenuated in the M- and L-segments, but the S-segment retains the virulent phenotype. MP-12 was manufactured as an Investigational New Drug vaccine by using MRC-5 cells and encodes a functional NSs gene, the major virulence factor of RVFV which 1 induces a shutoff of the host transcription, 2 inhibits interferon (IFN-β promoter activation, and 3 promotes the degradation of dsRNA-dependent protein kinase (PKR. MP-12 lacks a marker for differentiation of infected from vaccinated animals (DIVA. Although MP-12 lacking NSs works for DIVA, it does not replicate efficiently in type-I IFN-competent MRC-5 cells, while the use of type-I IFN-incompetent cells may negatively affect its genetic stability. To generate modified MP-12 vaccine candidates encoding a DIVA marker, while still replicating efficiently in MRC-5 cells, we generated recombinant MP-12 encoding Punta Toro virus Adames strain NSs (rMP12-PTNSs or Sandfly fever Sicilian virus NSs (rMP12-SFSNSs in place of MP-12 NSs. We have demonstrated that those recombinant MP-12 viruses inhibit IFN-β mRNA synthesis, yet do not promote the degradation of PKR. The rMP12-PTNSs, but not rMP12-SFSNSs, replicated more efficiently than recombinant MP-12 lacking NSs in MRC-5 cells. Mice vaccinated with rMP12-PTNSs or rMP12-SFSNSs induced neutralizing antibodies at a level equivalent to those vaccinated with MP-12, and were efficiently protected from wild-type RVFV challenge. The rMP12-PTNSs and rMP12-SFSNSs did not induce antibodies cross-reactive to anti-RVFV NSs antibody and are therefore applicable to DIVA. Thus, rMP12-PTNSs is highly efficacious, replicates efficiently in MRC-5 cells, and encodes a DIVA marker, all of which

  15. Development of a microarray for simultaneous detection and differentiation of different tospoviruses that are serologically related to Tomato spotted wilt virus.

    Science.gov (United States)

    Liu, Lu-Yuan; Ye, He-Yi; Chen, Tsang-Hai; Chen, Tsung-Chi

    2017-01-10

    Tospoviruses, the plant-infecting genus in the family Bunyaviridae, are thrips borne and cause severe agricultural losses worldwide. Based on the serological relationships of the structural nucleocapsid protein (NP), the current tospoviruses are divided into six serogroups. The use of NP-antisera is convenient for virus detection, but it is insufficient to identify virus species grouped in a serogroup due to the serological cross-reaction. Alternatively, virus species can be identified by the N gene amplification using specific primers. Tomato spotted wilt virus (TSWV) is the type species of the genus Tospovirus and one of the most destructive plant viruses. Eight known tospoviruses, Alstroemeria necrotic streak virus (ANSV), Chrysanthemum stem necrosis virus (CSNV), Groundnut ringspot virus (GRSV), Impatiens necrotic spot virus (INSV), Melon severe mosaic virus (MeSMV), Pepper necrotic spot virus (PNSV), Tomato chlorotic spot virus (TCSV) and Zucchini lethal chlorosis virus (ZLCV), sharing serological relatedness with TSWV in NP, are grouped in the TSWV serogroup. Most of the TSWV-serogroup viruses prevail in Europe and America. An efficient diagnostic method is necessary for inspecting these tospoviruses in Asia, including Taiwan. A microarray platform was developed for simultaneous detection and identification of TSWV-serogroup tospoviruses. Total RNAs extracted from Chenopodium quinoa leaves separately inoculated with ANSV, CSNV, GRSV, INSV, TCSV and TSWV were used for testing purposes. The 5'-biotinylated degenerate forward and reverse primers were designed from the consensus sequences of N genes of TSWV-serogroup tospoviruses for reverse transcription-polymerase chain reaction (RT-PCR) amplification. Virus-specific oligonucleotide probes were spotted on the surface of polyvinyl chloride (PVC) chips to hybridize with PCR products. The hybridization signals were visualized by hydrolysis of NBT/BCIP with streptavidine-conjugated alkaline phosphatase. The

  16. Epidemiology of spotted wilt disease of peanut caused by Tomato spotted wilt virus in the southeastern U.S.

    Science.gov (United States)

    Culbreath, A K; Srinivasan, R

    2011-08-01

    Spotted wilt disease of peanut (Arachis hypogaea) (SWP), caused by Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae), was first observed in Alabama, Florida, and Georgia in the late 1980s and rapidly became a major limiting factor for peanut production in the region. Tobacco thrips (Frankliniella fusca) and western flower thrips (Frankliniella occidentalis) both occur on peanut throughout the southeastern U.S., but F. fusca is the predominant species that reproduces on peanut, and is considered to be the more important vector. Several non-crop sources of potential primary vectors and TSWV inoculum have been identified, but their relative importance has not been determined. The peanut growing season in Alabama, Florida, and Georgia is from April through November, and 'volunteer' peanut plants can be present for much of the remainder of the year. Therefore peanut itself has huge potential for perpetuating both vector and virus. Symptoms are often evident within a few days of seedling emergence, and disease progress is often rapid within the first 50-60 days after planting. Based on destructive sampling and assays for TSWV, there is often a high incidence of asymptomatic infections even in peanut genotypes that produce few and mild symptoms of infection in the field. Severity of SWP epidemics fluctuates significantly from year to year. The variability has not been fully explained, but lower incidences have been associated with years categorized as "La Niña" in the El Niño-Southern Oscillation. Planting date can have a large effect on disease incidence within a location. This may be linked to the thrips reproductive cycle and environmental effects on the plant and plant-thrips-virus interactions. Row pattern, plant population, and in-furrow applications of phorate insecticide can also affect epidemics of SWP. Considerable progress has been made in developing cultivars with natural field resistance to TSWV. Use of cultivars with moderate field

  17. RNA Interference Restricts Rift Valley Fever Virus in Multiple Insect Systems.

    Science.gov (United States)

    Dietrich, Isabelle; Jansen, Stephanie; Fall, Gamou; Lorenzen, Stephan; Rudolf, Martin; Huber, Katrin; Heitmann, Anna; Schicht, Sabine; Ndiaye, El Hadji; Watson, Mick; Castelli, Ilaria; Brennan, Benjamin; Elliott, Richard M; Diallo, Mawlouth; Sall, Amadou A; Failloux, Anna-Bella; Schnettler, Esther; Kohl, Alain; Becker, Stefanie C

    2017-01-01

    The emerging bunyavirus Rift Valley fever virus (RVFV) is transmitted to humans and livestock by a large number of mosquito species. RNA interference (RNAi) has been characterized as an important innate immune defense mechanism used by mosquitoes to limit replication of positive-sense RNA flaviviruses and togaviruses; however, little is known about its role against negative-strand RNA viruses such as RVFV. We show that virus-specific small RNAs are produced in infected mosquito cells, in Drosophila melanogaster cells, and, most importantly, also in RVFV vector mosquitoes. By addressing the production of small RNAs in adult Aedes sp. and Culex quinquefasciatus mosquitoes, we showed the presence of virus-derived Piwi-interacting RNAs (piRNAs) not only in Aedes sp. but also in C. quinquefasciatus mosquitoes, indicating that antiviral RNA interference in C. quinquefasciatus mosquitoes is similar to the described activities of RNAi in Aedes sp. mosquitoes. We also show that these have antiviral activity, since silencing of RNAi pathway effectors enhances viral replication. Moreover, our data suggest that RVFV does not encode a suppressor of RNAi. These findings point toward a significant role of RNAi in the control of RVFV in mosquitoes. IMPORTANCE Rift Valley fever virus (RVFV; Phlebovirus, Bunyaviridae) is an emerging zoonotic mosquito-borne pathogen of high relevance for human and animal health. Successful strategies of intervention in RVFV transmission by its mosquito vectors and the prevention of human and veterinary disease rely on a better understanding of the mechanisms that govern RVFV-vector interactions. Despite its medical importance, little is known about the factors that govern RVFV replication, dissemination, and transmission in the invertebrate host. Here we studied the role of the antiviral RNA interference immune pathways in the defense against RVFV in natural vector mosquitoes and mosquito cells and draw comparisons to the model insect Drosophila

  18. A Haploid Genetic Screen Identifies Heparan Sulfate Proteoglycans Supporting Rift Valley Fever Virus Infection.

    Science.gov (United States)

    Riblett, Amber M; Blomen, Vincent A; Jae, Lucas T; Altamura, Louis A; Doms, Robert W; Brummelkamp, Thijn R; Wojcechowskyj, Jason A

    2015-11-18

    Rift Valley fever virus (RVFV) causes recurrent insect-borne epizootics throughout the African continent, and infection of humans can lead to a lethal hemorrhagic fever syndrome. Deep mutagenesis of haploid human cells was used to identify host factors required for RVFV infection. This screen identified a suite of enzymes involved in glycosaminoglycan (GAG) biogenesis and transport, including several components of the cis-oligomeric Golgi (COG) complex, one of the central components of Golgi complex trafficking. In addition, disruption of PTAR1 led to RVFV resistance as well as reduced heparan sulfate surface levels, consistent with recent observations that PTAR1-deficient cells exhibit altered Golgi complex morphology and glycosylation defects. A variety of biochemical and genetic approaches were utilized to show that both pathogenic and attenuated RVFV strains require GAGs for efficient infection on some, but not all, cell types, with the block to infection being at the level of virion attachment. Examination of other members of the Bunyaviridae family for GAG-dependent infection suggested that the interaction with GAGs is not universal among bunyaviruses, indicating that these viruses, as well as RVFV on certain cell types, employ additional unidentified virion attachment factors and/or receptors. Rift Valley fever virus (RVFV) is an emerging pathogen that can cause severe disease in humans and animals. Epizootics among livestock populations lead to high mortality rates and can be economically devastating. Human epidemics of Rift Valley fever, often initiated by contact with infected animals, are characterized by a febrile disease that sometimes leads to encephalitis or hemorrhagic fever. The global burden of the pathogen is increasing because it has recently disseminated beyond Africa, which is of particular concern because the virus can be transmitted by widely distributed mosquito species. There are no FDA-licensed vaccines or antiviral agents with activity

  19. Summer weeds as hosts for Frankliniella occidentalis and Frankliniella fusca (Thysanoptera: Thripidae) and as reservoirs for tomato spotted wilt Tospovirus in North Carolina.

    Science.gov (United States)

    Kahn, Noah D; Walgenbach, J F; Kennedy, G G

    2005-12-01

    In North Carolina, Tomato spotted wilt tospovirus (family Bunyaviridae, genus Tospovirus, TSWV) is vectored primarily by the tobacco thrips, Frankliniella fusca (Hinds), and the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). TSWV overwinters in winter annual weeds from which it is spread to susceptible crops in spring. Because most susceptible crops are destroyed after harvest before winter weeds emerge in the fall, infected summer weeds are thought to be the principal source for spread of TSWV to winter annual weeds in fall. A survey of summer weeds associated with TSWV-susceptible crops in the coastal plain of North Carolina conducted between May and October revealed that relatively few species were commonly infected with TSWV and supported populations of F. fusca or F. occidentalis. F. occidentalis made up > 75% of vector species collected from 15 summer weed species during 2002. The number of F. occidentalis and F. fusca immatures collected from plant samples varied significantly among plant species. Ipomoea purpurea (L.) Roth, Mollugo verticillata L., Cassia obtusifolia L., and Amaranthus palmeri S. Wats supported the largest numbers of immature F. occidentalis. Richardia scabra L., M. verticillata, and Ipomoea hederacea (L.) supported the largest numbers of F. fusca immatures. TSWV was present at 16 of 17 locations, and naturally occurring infections were found in 14 of 29 weed species tested. Five of the TSWV-infected species have not previously been reported as hosts of TSWV (A. palmeri, Solidago altissima L., Ipomoea lacunosa L., I. purpurea, and Phytolacca americana L.). Estimated rates of infection were highest in I. purpurea (6.8%), M. verticillata (5.3%), and I. hederacea (1.9%). When both the incidence of infection by TSWV and the populations of F. occidentalis and F. fusca associated with each weed species are considered, the following summer weed species have the potential to act as significant sources for

  20. A geographical information system-based multicriteria evaluation to map areas at risk for Rift Valley fever vector-borne transmission in Italy.

    Science.gov (United States)

    Tran, A; Ippoliti, C; Balenghien, T; Conte, A; Gely, M; Calistri, P; Goffredo, M; Baldet, T; Chevalier, V

    2013-11-01

    Rift Valley fever (RVF) is a severe mosquito-borne disease that is caused by a Phlebovirus (Bunyaviridae) and affects domestic ruminants and humans. Recently, its distribution widened, threatening Europe. The probability of the introduction and large-scale spread of Rift Valley fever virus (RVFV) in Europe is low, but localized RVF outbreaks may occur in areas where populations of ruminants and potential vectors are present. In this study, we assumed the introduction of the virus into Italy and focused on the risk of vector-borne transmission of RVFV to three main European potential hosts (cattle, sheep and goats). Five main potential mosquito vectors belonging to the Culex and Aedes genera that are present in Italy were identified in a literature review. We first modelled the geographical distribution of these five species based on expert knowledge and using land cover as a proxy of mosquito presence. The mosquito distribution maps were compared with field mosquito collections from Italy to validate the model. Next, the risk of RVFV transmission was modelled using a multicriteria evaluation (MCE) approach, integrating expert knowledge and the results of a literature review on host sensitivity and vector competence, feeding behaviour and abundance. A sensitivity analysis was performed to assess the robustness of the results with respect to expert choices. The resulting maps include (i) five maps of the vector distribution, (ii) a map of suitable areas for vector-borne transmission of RVFV and (iii) a map of the risk of RVFV vector-borne transmission to sensitive hosts given a viral introduction. Good agreement was found between the modelled presence probability and the observed presence or absence of each vector species. The resulting RVF risk map highlighted strong spatial heterogeneity and could be used to target surveillance. In conclusion, the geographical information system (GIS)-based MCE served as a valuable framework and a flexible tool for mapping the

  1. Oligomerization of Uukuniemi virus nucleocapsid protein

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    Katz Anna

    2010-08-01

    Full Text Available Abstract Background Uukuniemi virus (UUKV belongs to the Phlebovirus genus in the family Bunyaviridae. As a non-pathogenic virus for humans UUKV has served as a safe model bunyavirus in a number of studies addressing fundamental questions such as organization and regulation of viral genes, genome replication, structure and assembly. The present study is focused on the oligomerization of the UUKV nucleocapsid (N protein, which plays an important role in several steps of virus replication. The aim was to locate the domains involved in the N protein oligomerization and study the process in detail. Results A set of experiments concentrating on the N- and C-termini of the protein was performed, first by completely or partially deleting putative N-N-interaction domains and then by introducing point mutations of amino acid residues. Mutagenesis strategy was based on the computer modeling of secondary and tertiary structure of the N protein. The N protein mutants were studied in chemical cross-linking, immunofluorescence, mammalian two-hybrid, minigenome, and virus-like particle-forming assays. The data showed that the oligomerization ability of UUKV-N protein depends on the presence of intact α-helices on both termini of the N protein molecule and that a specific structure in the N-terminal region plays a crucial role in the N-N interaction(s. This structure is formed by two α-helices, rich in amino acid residues with aromatic (W7, F10, W19, F27, F31 or long aliphatic (I14, I24 side chains. Furthermore, some of the N-terminal mutations (e.g. I14A, I24A, F31A affected the N protein functionality both in mammalian two-hybrid and minigenome assays. Conclusions UUKV-N protein has ability to form oligomers in chemical cross-linking and mammalian two-hybrid assays. In mutational analysis, some of the introduced single-point mutations abolished the N protein functionality both in mammalian two-hybrid and minigenome assays, suggesting that especially the N

  2. Differential expression of tomato spotted wilt virus-derived viral small RNAs in infected commercial and experimental host plants.

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    Neena Mitter

    Full Text Available BACKGROUND: Viral small RNAs (vsiRNAs in the infected host can be generated from viral double-stranded RNA replicative intermediates, self-complementary regions of the viral genome or from the action of host RNA-dependent RNA polymerases on viral templates. The vsiRNA abundance and profile as well as the endogenous small RNA population can vary between different hosts infected by the same virus influencing viral pathogenicity and host response. There are no reports on the analysis of vsiRNAs of Tomato spotted wilt virus (TSWV, a segmented negative stranded RNA virus in the family Bunyaviridae, with two of its gene segments showing ambisense gene arrangement. The virus causes significant economic losses to numerous field and horticultural crops worldwide. PRINCIPAL FINDINGS: Tomato spotted wilt virus (TSWV-specific vsiRNAs were characterized by deep sequencing in virus-infected experimental host Nicotiana benthamiana and a commercial, susceptible host tomato. The total small (s RNA reads in TSWV-infected tomato sample showed relatively equal distribution of 21, 22 and 24 nt, whereas N. benthamiana sample was dominated by 24 nt total sRNAs. The number of vsiRNA reads detected in tomato was many a magnitude (~350:1 higher than those found in N. benthamiana, however the profile of vsiRNAs in terms of relative abundance 21, 22 and 24 nt class size was similar in both the hosts. Maximum vsiRNA reads were obtained for the M RNA segment of TSWV while the largest L RNA segment had the least number of vsiRNAs in both tomato and N. benthamiana. Only the silencing suppressor, NSs, of TSWV recorded higher antisense vsiRNA with respect to the coding frame among all the genes of TSWV. SIGNIFICANCE: Details of the origin, distribution and abundance of TSWV vsiRNAs could be useful in designing efficient targets for exploiting RNA interference for virus resistance. It also has major implications toward our understanding of the differential processing of vsi

  3. Modeling Severe Fever with Thrombocytopenia Syndrome Virus Infection in Golden Syrian Hamsters: Importance of STAT2 in Preventing Disease and Effective Treatment with Favipiravir.

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    Gowen, Brian B; Westover, Jonna B; Miao, Jinxin; Van Wettere, Arnaud J; Rigas, Johanna D; Hickerson, Brady T; Jung, Kie-Hoon; Li, Rong; Conrad, Bettina L; Nielson, Skot; Furuta, Yousuke; Wang, Zhongde

    2017-02-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease endemic in parts of Asia. The etiologic agent, SFTS virus (SFTSV; family Bunyaviridae, genus Phlebovirus) has caused significant morbidity and mortality in China, South Korea, and Japan, with key features of disease being intense fever, thrombocytopenia, and leukopenia. Case fatality rates are estimated to be in the 30% range, and no antivirals or vaccines are approved for use for treatment and prevention of SFTS. There is evidence that in human cells, SFTSV sequesters STAT proteins in replication complexes, thereby inhibiting type I interferon signaling. Here, we demonstrate that hamsters devoid of functional STAT2 are highly susceptible to as few as 10 PFU of SFTSV, with animals generally succumbing within 5 to 6 days after subcutaneous challenge. The disease included marked thrombocytopenia and inflammatory disease characteristic of the condition in humans. Infectious virus titers were present in the blood and most tissues 3 days after virus challenge, and severe inflammatory lesions were found in the spleen and liver samples of SFTSV-infected hamsters. We also show that SFTSV infection in STAT2 knockout (KO) hamsters is responsive to favipiravir treatment, which protected all animals from lethal disease and reduced serum and tissue viral loads by 3 to 6 orders of magnitude. Taken together, our results provide additional insights into the pathogenesis of SFTSV infection and support the use of the newly described STAT2 KO hamster model for evaluation of promising antiviral therapies. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease for which there are currently no therapeutic options or available vaccines. The causative agent, SFTS virus (SFTSV), is present in China, South Korea, and Japan, and infections requiring medical attention result in death in as many as 30% of the cases. Here, we describe a novel model of SFTS in hamsters genetically

  4. Crimean-Congo Hemorrhagic Fever Virus Nucleocapsid Protein Augments mRNA Translation.

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    Jeeva, Subbiah; Cheng, Erdong; Ganaie, Safder S; Mir, Mohammad A

    2017-08-01

    Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne Nairovirus of the Bunyaviridae family, causing severe illness with high mortality rates in humans. Here, we demonstrate that CCHFV nucleocapsid protein (CCHFV-NP) augments mRNA translation. CCHFV-NP binds to the viral mRNA 5' untranslated region (UTR) with high affinity. It facilitates the translation of reporter mRNA both in vivo and in vitro with the assistance of the viral mRNA 5' UTR. CCHFV-NP equally favors the translation of both capped and uncapped mRNAs, demonstrating the independence of this translation strategy on the 5' cap. Unlike the canonical host translation machinery, inhibition of eIF4F complex, an amalgam of three initiation factors, eIF4A, eIF4G, and eIF4E, by the chemical inhibitor 4E1RCat did not impact the CCHFV-NP-mediated translation mechanism. However, the proteolytic degradation of eIF4G alone by the human rhinovirus 2A protease abrogated this translation strategy. Our results demonstrate that eIF4F complex formation is not required but eIF4G plays a critical role in this translation mechanism. Our results suggest that CCHFV has adopted a unique translation mechanism to facilitate the translation of viral mRNAs in the host cell cytoplasm where cellular transcripts are competing for the same translation apparatus.IMPORTANCE Crimean-Congo hemorrhagic fever, a highly contagious viral disease endemic to more than 30 countries, has limited treatment options. Our results demonstrate that NP favors the translation of a reporter mRNA harboring the viral mRNA 5' UTR. It is highly likely that CCHFV uses an NP-mediated translation strategy for the rapid synthesis of viral proteins during the course of infection. Shutdown of this translation mechanism might selectively impact viral protein synthesis, suggesting that an NP-mediated translation strategy is a target for therapeutic intervention against this viral disease. Copyright © 2017 American Society for Microbiology.

  5. Emerging and Reemeriging Human Bunyavirus Infections and Climate Change

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    Sutherland, Laura J.; Anyamba, Assaf; LaBeaud, A. Desiree

    2013-01-01

    The Bunyaviridae family includes a growing number of viruses that have contributed to the burden of emerging and reemerging infectious diseases around the globe. Many of these viruses cause severe clinical outcomes in human and animal populations, the results of which can be detrimental to public health and the economies of affected communities. The threat to endemic and non-native regions is particularly high, and national and international public health agencies are often on alert. Many of the bunyaviruses cause severe clinical disease including hemorrhage, organ failure, and death leading to their high-risk classification. Hantaviruses and Rift Valley fever virus (RVFV) (genus Phlebovirus) are National Institute of Allergy and Infectious Diseases Category A priority pathogens in the United States. Viral hemorrhagic fevers, a classification that includes many bunyaviruses, are immediately notifiable in the European Union. The emergence of new and reemerging bunyaviruses has resulted in numerous human and animal fatalities. Outbreaks of Rift Valley fever (RVF) in East Africa (1997/1998, 2006/2007), Sudan (2007), Southern Africa (2008-2010), Kenya (1997/1998, 2006/2007) (Anyamba et al., 2009, 2010; Breiman et al., 2010; Grobbelaar et al., 2011; Woods et al., 2002) and Saudi Arabia & Yemen (2000, 2010) (Food and Agriculture Organization, 2000; Hjelle and Glass, 2000; Madani et al., 2003) and the emergence of Sin Nombre virus (1993) (Hjelle and Glass, 2000) and most recently Schmallenberg virus (2011) (DEFRA, 2012) are prime examples of the devastating and worldwide toll bunyaviruses have on health and economies. Climate variability (precipitation and temperature in particular) greatly influence the ecological conditions that drive arboviral disease outbreaks across the globe. Several human and animal disease outbreaks have been influenced by changes in climate associated with the El Niño Southern Oscillation (ENSO) phenomenon including the bunyaviruses RVFV and Sin

  6. Generic amplification and next generation sequencing reveal Crimean-Congo hemorrhagic fever virus AP92-like strain and distinct tick phleboviruses in Anatolia, Turkey.

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    Dinçer, Ender; Brinkmann, Annika; Hekimoğlu, Olcay; Hacıoğlu, Sabri; Földes, Katalin; Karapınar, Zeynep; Polat, Pelin Fatoş; Oğuz, Bekir; Orunç Kılınç, Özlem; Hagedorn, Peter; Özer, Nurdan; Özkul, Aykut; Nitsche, Andreas; Ergünay, Koray

    2017-07-14

    Ticks are involved with the transmission of several viruses with significant health impact. As incidences of tick-borne viral infections are rising, several novel and divergent tick- associated viruses have recently been documented to exist and circulate worldwide. This study was performed as a cross-sectional screening for all major tick-borne viruses in several regions in Turkey. Next generation sequencing (NGS) was employed for virus genome characterization. Ticks were collected at 43 locations in 14 provinces across the Aegean, Thrace, Mediterranean, Black Sea, central, southern and eastern regions of Anatolia during 2014-2016. Following morphological identification, ticks were pooled and analysed via generic nucleic acid amplification of the viruses belonging to the genera Flavivirus, Nairovirus and Phlebovirus of the families Flaviviridae and Bunyaviridae, followed by sequencing and NGS in selected specimens. A total of 814 specimens, comprising 13 tick species, were collected and evaluated in 187 pools. Nairovirus and phlebovirus assays were positive in 6 (3.2%) and 48 (25.6%) pools. All nairovirus sequences were closely-related to the Crimean-Congo hemorrhagic fever virus (CCHFV) strain AP92 and formed a phylogenetically distinct cluster among related strains. Major portions of the CCHFV genomic segments were obtained via NGS. Phlebovirus sequencing revealed several tick-associated virus clades, including previously-characterized Antigone, Lesvos, KarMa and Bole tick viruses, as well as a novel clade. A wider host range for tick-associated virus strains has been observed. NGS provided near-complete sequences of the L genomic segments of Antigone and KarMa clades, as well as Antigone partial S segment. Co- infections of CCHFV and KarMa or novel phlebovirus clades were detected in 2.1% of the specimens. Widespread circulation of various tick-associated phlebovirus clades were documented for the first time in Anatolia. Genomes of CCHFV AP92 strains were

  7. Transcriptome-wide identification of host genes targeted by tomato spotted wilt virus-derived small interfering RNAs.

    Science.gov (United States)

    Ramesh, Shunmugiah V; Williams, Sarah; Kappagantu, Madhu; Mitter, Neena; Pappu, Hanu R

    2017-06-15

    RNA silencing mechanism functions as a major defense against invading viruses. The caveat in the RNA silencing mechanism is that the effector small interfering RNAs (siRNAs) act on any RNA transcripts with sequence complementarity irrespective of target's origin. A subset of highly expressed viral small interfering RNAs (vsiRNAs) derived from the tomato spotted wilt virus (TSWV; Tospovirus: Bunyaviridae) genome was analyzed for their propensity to downregulate the tomato transcriptome. A total of 11898 putative target sites on tomato transcripts were found to exhibit a propensity for down regulation by TSWV-derived vsiRNAs. In total, 2450 unique vsiRNAs were found to have potential cross-reacting capability with the tomato transcriptome. VsiRNAs were found to potentially target a gamut of host genes involved in basal cellular activities including enzymes, transcription factors, membrane transporters, and cytoskeletal proteins. KEGG pathway annotation of targets revealed that the vsiRNAs were mapped to secondary metabolite biosynthesis, amino acids, starch and sucrose metabolism, and carbon and purine metabolism. Transcripts for protein processing, hormone signalling, and plant-pathogen interactions were the most likely targets from the genetic, environmental information processing, and organismal systems, respectively. qRT-PCR validation of target gene expression showed that none of the selected transcripts from tomato cv. Marglobe showed up regulation, and all were down regulated even upto 20 folds (high affinity glucose transporter). However, the expression levels of transcripts from cv. Red Defender revealed differential regulation as three among the target transcripts showed up regulation (Cc-nbs-lrr, resistance protein, AP2-like ethylene-responsive transcription factor, and heat stress transcription factor A3). Accumulation of tomato target mRNAs of corresponding length was proved in both tomato cultivars using 5' RACE analysis. The TSWV-tomato interaction at

  8. Differential expression of tomato spotted wilt virus-derived viral small RNAs in infected commercial and experimental host plants.

    Science.gov (United States)

    Mitter, Neena; Koundal, Vikas; Williams, Sarah; Pappu, Hanu

    2013-01-01

    Viral small RNAs (vsiRNAs) in the infected host can be generated from viral double-stranded RNA replicative intermediates, self-complementary regions of the viral genome or from the action of host RNA-dependent RNA polymerases on viral templates. The vsiRNA abundance and profile as well as the endogenous small RNA population can vary between different hosts infected by the same virus influencing viral pathogenicity and host response. There are no reports on the analysis of vsiRNAs of Tomato spotted wilt virus (TSWV), a segmented negative stranded RNA virus in the family Bunyaviridae, with two of its gene segments showing ambisense gene arrangement. The virus causes significant economic losses to numerous field and horticultural crops worldwide. Tomato spotted wilt virus (TSWV)-specific vsiRNAs were characterized by deep sequencing in virus-infected experimental host Nicotiana benthamiana and a commercial, susceptible host tomato. The total small (s) RNA reads in TSWV-infected tomato sample showed relatively equal distribution of 21, 22 and 24 nt, whereas N. benthamiana sample was dominated by 24 nt total sRNAs. The number of vsiRNA reads detected in tomato was many a magnitude (~350:1) higher than those found in N. benthamiana, however the profile of vsiRNAs in terms of relative abundance 21, 22 and 24 nt class size was similar in both the hosts. Maximum vsiRNA reads were obtained for the M RNA segment of TSWV while the largest L RNA segment had the least number of vsiRNAs in both tomato and N. benthamiana. Only the silencing suppressor, NSs, of TSWV recorded higher antisense vsiRNA with respect to the coding frame among all the genes of TSWV. Details of the origin, distribution and abundance of TSWV vsiRNAs could be useful in designing efficient targets for exploiting RNA interference for virus resistance. It also has major implications toward our understanding of the differential processing of vsiRNAs in antiviral defense and viral pathogenicity.

  9. Extracellular Vesicles Mediate Receptor-Independent Transmission of Novel Tick-Borne Bunyavirus

    Science.gov (United States)

    Silvas, Jesus A.; Popov, Vsevolod L.; Paulucci-Holthauzen, Adriana

    2015-01-01

    ABSTRACT Severe fever with thrombocytopenia syndrome (SFTS) virus is a newly recognized member of the genus Phlebovirus in the family Bunyaviridae. The virus was isolated from patients presenting with hemorrhagic manifestations and an initial case fatality rate of 12 to 30% was reported. Due to the recent emergence of this pathogen, there is limited knowledge on the molecular virology of SFTS virus. Recently, we reported that the SFTS virus NSs protein inhibited the activation of the beta interferon (IFN-β) promoter. Furthermore, we also found that SFTS virus NSs relocalizes key components of the IFN response into NSs-induced cytoplasmic structures. Due to the important role these structures play during SFTS virus replication, we conducted live cell imaging studies to gain further insight into the role and trafficking of these cytoplasmic structures during virus infection. We found that some of the SFTS virus NSs-positive cytoplasmic structures were secreted to the extracellular space and endocytosed by neighboring cells. We also found that these secreted structures isolated from NSs-expressing cells and SFTS virus-infected cells were positive for the viral protein NSs and the host protein CD63, a protein associated with extracellular vesicles. Electron microscopy studies also revealed that the isolated CD63-immunoprecipitated extracellular vesicles produced during SFTS virus infection contained virions. The virions harbored within these structures were efficiently delivered to uninfected cells and were able to sustain SFTS virus replication. Altogether, these results suggest that SFTS virus exploits extracellular vesicles to mediate virus receptor-independent transmission to host cells and open the avenue for novel therapeutic strategies against SFTS virus and related pathogens. IMPORTANCE SFTS virus is novel bunyavirus associated with hemorrhagic fever illness. Currently, limited information is available about SFTS virus. In the present study, we demonstrated

  10. Experimental evaluation of sand fly collection and storage methods for the isolation and molecular detection of Phlebotomus-borne viruses.

    Science.gov (United States)

    Remoli, Maria Elena; Bongiorno, Gioia; Fortuna, Claudia; Marchi, Antonella; Bianchi, Riccardo; Khoury, Cristina; Ciufolini, Maria Grazia; Gramiccia, Marina

    2015-11-09

    Several viruses have been recently isolated from Mediterranean phlebotomine sand flies; some are known to cause human disease while some are new to science. To monitor the Phlebotomus-borne viruses spreading, field studies are in progress using different sand fly collection and storage methods. Two main sampling techniques consist of CDC light traps, an attraction method allowing collection of live insects in which the virus is presumed to be fairly preserved, and sticky traps, an interception method suitable to collect dead specimens in high numbers, with a risk for virus viability or integrity. Sand flies storage requires a "deep cold chain" or specimen preservation in ethanol. In the present study the influence of sand fly collection and storage methods on viral isolation and RNA detection performances was evaluated experimentally. Specimens of laboratory-reared Phlebotomus perniciosus were artificially fed with blood containing Toscana virus (family Bunyaviridae, genus Phlebovirus). Various collection and storage conditions of blood-fed females were evaluated to mimic field procedures using single and pool samples. Isolation on VERO cell cultures, quantitative Real time-Retro-transcriptase (RT)-PCR and Nested-RT-PCR were performed according to techniques commonly used in surveillance studies. Live engorged sand flies stored immediately at -80 °C were the most suitable sample for phlebovirus identification by both virus isolation and RNA detection. The viral isolation rate remained very high (26/28) for single dead engorged females frozen after 1 day, while it was moderate (10/30) for specimens collected by sticky traps maintained up to 3 days at room temperature and then stored frozen without ethanol. Opposed to viral isolation, molecular RNA detection kept very high on dead sand flies collected by sticky traps when left at room temperature up to 6 days post blood meal and then stored frozen in presence (88/95) or absence (87/88) of ethanol. Data were

  11. Role of Culex and Anopheles mosquito species as potential vectors of rift valley fever virus in Sudan outbreak, 2007

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    Galal Fatma H

    2010-03-01

    Full Text Available Abstract Background Rift Valley fever (RVF is an acute febrile arthropod-borne viral disease of man and animals caused by a member of the Phlebovirus genus, one of the five genera in the family Bunyaviridae. RVF virus (RVFV is transmitted between animals and human by mosquitoes, particularly those belonging to the Culex, Anopheles and Aedes genera. Methods Experiments were designed during RVF outbreak, 2007 in Sudan to provide an answer about many raised questions about the estimated role of vector in RVFV epidemiology. During this study, adult and immature mosquito species were collected from Khartoum and White Nile states, identified and species abundance was calculated. All samples were frozen individually for further virus detection. Total RNA was extracted from individual insects and RVF virus was detected from Culex, Anopheles and Aedes species using RT-PCR. In addition, data were collected about human cases up to November 24th, 2007 to asses the situation of the disease in affected states. Furthermore, a historical background of the RVF outbreaks was discussed in relation to global climatic anomalies and incriminated vector species. Results A total of 978 mosquitoes, belonging to 3 genera and 7 species, were collected during Sudan outbreak, 2007. Anopheles gambiae arabiensis was the most frequent species (80.7% in White Nile state. Meanwhile, Cx. pipiens complex was the most abundant species (91.2% in Khartoum state. RT-PCR was used and successfully amplified 551 bp within the M segment of the tripartite negative-sense single stranded RNA genome of RVFV. The virus was detected in female, male and larval stages of Culex and Anopheles species. The most affected human age interval was 15-29 years old followed by ≥ 45 years old, 30-44 years old, and then 5-14 years old. Regarding to the profession, housewives followed by farmers, students, shepherd, workers and the free were more vulnerable to the infection. Furthermore, connection between

  12. Hantavirus del nuevo mundo: Ecología y epidemiología de un virus emergente en latinoamérica The New-World Hantaviruses: Ecology and epidemiology of an emerging virus in Latin America

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    Henry Puerta

    2006-08-01

    Full Text Available Los hantavirus son un grupo de patógenos emergentes (familia Bunyaviridae; género Hantavirus identificados como agentes etiológicos de la Fiebre Hemorrágica con Síndrome Renal (FHSR en Europa y Asia y el Síndrome Cardiopulmonar por Hantavirus (SCPH en las Américas. La FHSR está relacionada con roedores de las subfamilias Murinae y Arvicolinae y el SCPH con roedores de las subfamilias Sigmodontinae y Arvicolinae. Desde la identificación del SCPH en los EE.UU. en 1993, muchos casos de SCPH y un número cada vez mayor de hantavirus y sus roedores reservorios han sido identificados en Centro y Sud América. Estudios epidemiológicos han demostrado diferencias notables en las seroprevalencias de anticuerpos en humanos y roedores reservorios que oscilan entre el 1% y más del 40%. Hasta ahora han sido notificados en toda América más de 1500 casos de SCPH y aproximadamente más de 15 variantes de hantavirus genética y serológicamente distintos asociados a roedores sigmodontinos. Las formas clínicas leves-autolimitadas, moderadas y graves de la enfermedad, los antecedentes de transmisión persona a persona y una incidencia mayor de manifestaciones clínicas extrapulmonares que se diferencian de la enfermedad clásica descrita por primera vez en EE.UU., son aspectos importantes sobre la epidemiología de los hantavirus y el SCPH en Latinoamérica; sin embargo, la historia completa de los hantavirus está aún por escribirse, debido a la naturaleza dinámica de estos virus y sus patologías, y a la complejidad de los factores que intervienen en su aparición, establecimiento y diseminación en poblaciones humanas y animales. Latinoamérica continúa representando la porción del continente con una oportunidad única y desafiante para el estudio de la relación de los hantavirus con sus huéspedes reservorios naturales y las interacciones virus-roedor-humano. Probablemente más hantavirus podrían ser descritos en el futuro, y ser

  13. CONTROL OF VIRAL DISEASES TRANSMITTED IN A PERSISTENT MANNER BY THRIPS IN PEPPER (TOMATO SPOTTED WILT VIRUS).

    Science.gov (United States)

    Fanigliulo, A; Viggiano, A; Gualco, A; Crescenzi, A

    2014-01-01

    Tomato spotted wilt disease is caused by Tomato Spotted Wilt Virus (TSWV) (Tospovirus, Bunyaviridae), a virus that severely damages and reduces the yield of many economically important plants worldwide and actually it is a major disease affecting the production of tomato and pepper in Italy. Due to the non-predictive nature of its outbreaks combined with the lack of forecasting, adoption of preventive measures have not always been practical, in fact the disease cycle has proven to be extremely difficult to break because of the wide and often overlapping host range of both the virus and the thrips vectors, which transmit the virus in a persistent, circulative, and propagative manner. Moreover recently, resistance breaking (RB) isolates of TSWV that overcome the resistance conferred by the Tsw gene in different pepper hybrids have been recovered in different locations in Italy and also in Brazil, USA, Spain and Australia, and this occurrence raises the question on the importance of a new approach of integrated pest management for TSWV management, including both control of its insect vector and the induction of the plant's resistance against viral infection. In this perspective, a study was performed in 2012 and 2013 with the purpose of evaluating the efficacy of the insecticide Cyantraniliprole alone or combined with Acibenzolar-S-Methyl (ASM), inducer of systemic acquired resistance, in the control of tomato spotted wilt disease in pepper. The experiment was performed in laboratory, in a thermo-conditioned greenhouse, into separate insect-proof cages and consisted of 5 treatments and 2 applications (plus a pre-transplant application for treatments were ASM was used. Variables were the mode of application of ASM in pre-transplant (by foliar or by drench) and the duration of the exposure time of the treated plants to viruliferous insects. Pepper cv. Corno di Toro, devoid of any resistance to TSWV, was used. Plants were observed daily to record any symptom induced by

  14. Níveis de anticorpos para arbovírus em indivíduos da região de Ribeirão Preto, SP (Brasil Arbovirus antibody levels in the population of the Ribeirão Preto area, S.Paulo State (Brazil

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    Luiz Tadeu Moraes Figueiredo

    1986-06-01

    Full Text Available Com o objetivo de conhecer os níveis de anticorpos para arbovírus, foram estudados 302 indivíduos da região de Ribeirão Preto (Brasil, moradores em 3 tipos de locais com distintas formas de organização do espaço: próximos à área de paisagem natural; com paisagem modificada para a agropecuária; comunidades urbanas. Foram efetuados testes sorológicos de inibição da hemaglutinação, neutralização e fixação do complemento para 21 arbovírus. Os resultados mostraram que 19,9% dos indivíduos investigados apresentaram anticorpos, sugerindo infecções pregressas por vários arbovírus. A maior percentagem de habitantes que se infectaram por estes agentes foi observada em locais próximos à área de paisagem natural, 38,5%. O vesiculovírus Piry foi o agente para o qual se encontrou o maior número de soros reagentes, 12,5%. A maior ocorrência de portadores de anticorpos para o vírus Piry foi observada nos indivíduos: do sexo masculino; com idade superior a 40 anos; guardas-florestais, lavradores e profissionais com atividades ligadas ao rio.The area of Ribeirão Preto is located in the north of S.Paulo State - Brazil. The population is 611,742. The climate is sub-tropical warm and humid. The area of Ribeirão Preto is almost completely deforested and covered by extensive plantations of sugar cane and coffee and pasture. With the purpose of discovering the arbovirus antibody levels, a serologic survey was carried out among people of the Ribeirão Preto area living in different geographical environments. Fifty two inhabitants located close to natural landscap, 38 in places with landscape modified by agriculture and cattle raising, and 93 in urban communities were studied. Serologic tests for hemagglutination inhibition by 20 Togaviridae and Bunyaviridae arbovirus, and neutralization and complement fixation tests on Piry Rhabdoviridae were carried out. It was discovered that 19.9% of the sample population presented antibodies

  15. Pigeonpea sterility mosaic virus: a legume-infecting Emaravirus from South Asia.

    Science.gov (United States)

    Patil, Basavaprabhu L; Kumar, P Lava

    2015-10-01

    support the vector A. cajani. SMD is endemic in most of the pigeonpea-growing regions of India, but the incidence varies widely between regions and years. In nature, A. cajani populations were almost exclusively observed on SMD-infected pigeonpea, but not on healthy plants, indicating a strong communalistic relationship between the virus-infected plants and the vector. The epidemiology of SMD involves the virus, mite vector, cultivar and environmental conditions. Infected perennial and volunteer plants serve as a source for both the virus and its vector mites, and play an important role in the disease cycle. The PPSMV genome contains five segments of single-stranded RNA that are predicted to encode proteins in negative sense. The ribonucleoprotein complex is encased in quasi-spherical, membrane-bound virus particles of 100-150 nm. The largest segment, RNA-1, is 7022 nucleotides in length and codes for RNA-dependent RNA polymerase (2295 amino acids); RNA-2, with a sequence length of 2223 nucleotides, codes for glycoproteins (649 amino acids); RNA-3, with a sequence length of 1442 nucleotides, codes for nucleocapsid protein (309 amino acids); RNA-4, with a sequence length of 1563 nucleotides, codes for a putative movement protein p4 (362 amino acids); and RNA-5, with a sequence length of 1689 nucleotides, codes for p5 (474 amino acids), a protein with unknown function. PPSMV was recently classified as a species in the genus Emaravirus, a genus whose members show features resembling those of members of the genera Tospovirus (Family: Bunyaviridae) and Tenuivirus, both of which comprise single-stranded RNA viruses that encode proteins by an ambisense strategy. The disease is mainly controlled using SMD-resistant cultivars. However, the occurrence of distinct strains/isolates of PPSMV in different locations makes it difficult to incorporate broad-spectrum resistance. Studies on the inheritance of SMD resistance in different cultivars against different isolates of PPSMV