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assessing the impact of climate change on vector-borne viruses in the eu through the elicitation of expert opinion.expert opinion was elicited to undertake a qualitative risk assessment to estimate the current and future risks to the european union (eu) from five vector-borne viruses listed by the world organization for animal health. it was predicted that climate change will increase the risk of incursions of african horse sickness virus (ahsv), crimean-congo haemorrhagic fever virus (cchfv) and rift valley fever virus (rvfv) into the eu from other parts of the world, with african swine fever virus (asfv) a ...201019580695
a comparison of the susceptibility of the biting midge culicoides imicola to infection with recent and historical isolates of african horse sickness virus.the susceptibility of culicoides (avaritia) imicola kiefer (diptera: ceratopogonidae) to 21 isolates representing all nine known serotypes of african horse sickness virus (ahsv), recovered from clinical cases of the disease in south africa during 1998-2004, was compared with its susceptibility to approximately 40-year-old isolates stored at the agricultural research council-onderstepoort veterinary institute. field-collected c. imicola were fed through a chicken skin membrane on sheep blood spik ...201020626628
assessment of bluetongue viraemia in sheep by real-time pcr and correlation with viral infectivity.inoculation of embryonated chicken eggs is the standard method for the titration of infectious bluetongue virus (btv). here, six rna extraction methods coupled with optimised dsrna denaturation and real-time rt-pcr were evaluated for the quantitation of btv in blood samples from experimentally infected sheep and results were correlated to infectious virus titres. an exogenous dsrna internal control (ic) from the closely related epizootic hemorrhagic disease virus (ehdv) was used to assess the ef ...201020691732
membrane permeabilization of the african horse sickness virus vp5 protein is mediated by two n-terminal amphipathic α-helices.the vp5 outer capsid protein of african horse sickness virus (ahsv) is cytotoxic when expressed in spodoptera frugiperda (sf-9) cells. secondary structure analysis of the vp5 amino acid sequence of ahsv-9 identified two n-terminal amphipathic α-helices within the first 43 amino acids. baculovirus expression of n- and c-terminal truncated vp5 proteins in sf-9 cells indicated that the n-terminal 43 amino acids correlated with low levels of protein expression and with increased membrane permeabiliz ...201021193936
development and optimisation of a duplex real-time reverse transcription quantitative pcr assay targeting the vp7 and ns2 genes of african horse sickness virus.nucleotide sequences of 52 south african isolates of african horse sickness virus (ahsv) collected during 2004-2005 and including viruses of all nine ahsv serotypes, were used to design and develop a duplex real-time reverse transcription quantitative pcr (rt-pcr) assay targeting the vp7 (s8) and ns2 (s9) genes of ahsv. the assay was optimized for detection of ahsv in fresh and frozen blood of naturally infected horses. assay performance was enhanced using random hexamers rather than gene-specif ...201020304015
re-emergence of bluetongue, african horse sickness, and other orbivirus diseases.arthropod-transmitted viruses (arboviruses) are important causes of disease in humans and animals, and it is proposed that climate change will increase the distribution and severity of arboviral diseases. orbiviruses are the cause of important and apparently emerging arboviral diseases of livestock, including bluetongue virus (btv), african horse sickness virus (ahsv), equine encephalosis virus (eev), and epizootic hemorrhagic disease virus (ehdv) that are all transmitted by haematophagous culic ...201020167199
identifying equine premises at high risk of introduction of vector-borne diseases using geo-statistical and space-time analyses.the identification of premises that may play an important role in the introduction or spread of animal diseases is fundamental to the development of risk-based surveillance and control programs. a combination of geo-statistical and cluster analysis methods was used to identify geographical areas and periods of time at highest risk for introduction of the african horse sickness virus (ahsv) into the castile and leon (cyl) region of spain. risk was estimated based on the predicted premises-specifi ...201121377227
animal diseases caused by orbiviruses, algeria.antibodies against bluetongue virus were detected in cattle, sheep, goats, and camels in algeria in 2008. antibodies against epizootic hemorrhagic disease virus were detected in cattle, but antibodies against african horse sickness virus were not detected in horses and mules. epizootic hemorrhagic disease in northern africa poses a major risk for the european union.201122172371
serological survey of african horse sickness in selected districts of jimma zone, southwestern ethiopia.a cross-sectional serological survey was undertaken in selected districts of different agro-ecology of jimma zone (dedo, yebu, seka, serbo, and jimma town) from november 2009 to february 2010 to determine the seroprevalence of african horse sickness virus and associated risk factors of the disease. two hundred seventy-four equids (189 horses, 43 mules, and 47 donkeys) with a history of non-vaccination for at least 2 years were selected randomly from the above areas. sera samples were collected a ...201121465102
african horse sickness in the gambia: circulation of a live-attenuated vaccine-derived strain.summaryafrican horse sickness virus serotype 9 (ahsv-9) has been known for some time to be circulating amongst equids in west africa without causing any clinical disease in indigenous horse populations. whether this is due to local breeds of horses being resistant to disease or whether the ahsv-9 strains circulating are avirulent is currently unknown. this study shows that the majority (96%) of horses and donkeys sampled across the gambia were seropositive for ahs, despite most being unvaccinate ...201121733265
African horse sickness virus induces apoptosis in cultured mammalian cells.Infection of mammalian cell cultures with African horse sickness virus (AHSV) is known to result in dramatic cytopathic effects (CPE), but no CPE is observed in infected insect cell cultures despite productive virus replication. The basis for this phenomenon has not yet been investigated, but is suggestive of apoptosis being induced following virus infection of the mammalian cells. To investigate whether AHSV can induce apoptosis in infected mammalian cells, Culicoides variipennis (KC) insect ce ...201121983259
Temperature dependence of the extrinsic incubation period of orbiviruses in culicoides biting midges.The rate at which viruses replicate and disseminate in competent arthropod vectors is limited by the temperature of their environment, and this can be an important determinant of geographical and seasonal limits to their transmission by arthropods in temperate regions.201122125649
comparison of two trapping methods for culicoides biting midges and determination of african horse sickness virus prevalence in midge populations at onderstepoort, south africa.culicoides biting midges (diptera: ceratopogonidae) are vectors of a variety of pathogens including african horse sickness virus (ahsv), a member of the family reoviridae, genus orbivirus. ahsv causes african horse sickness (ahs), an endemic disease of equids with an extremely high mortality rate in horses in sub-saharan africa. culicoides (avaritia) imicola kieffer is considered to be the principal vector of ahsv and is the dominant culicoides species in south africa. due to the global distribu ...201122014560
a modified vaccinia ankara virus (mva) vaccine expressing african horse sickness virus (ahsv) vp2 protects against ahsv challenge in an ifnar -/- mouse model.african horse sickness (ahs) is a lethal viral disease of equids, which is transmitted by culicoides midges that become infected after biting a viraemic host. the use of live attenuated vaccines has been vital for the control of this disease in endemic regions. however, there are safety concerns over their use in non-endemic countries. research efforts over the last two decades have therefore focused on developing alternative vaccines based on recombinant baculovirus or live viral vectors expres ...201121298069
a new duplex real-time rt-pcr assay for sensitive and specific detection of african horse sickness virus.a new real-time reverse transcription-polymerase chain reaction (rt-pcr) assay for a simple and rapid diagnosis of african horse sickness (ahs) was developed. primers and fam-labeled taqman-mgb probes specific for african horse sickness virus (ahsv) were selected from the consensus sequence of the segment 8 of all 9 serotypes of ahsv reference strains. for the determination of the analytical sensitivity, an in vitro transcript (ahs_ns2t7) of the target region was constructed and tested. furtherm ...201121315146
tissue tropism of african horsesickness virus in the chicken embryo demonstrated with the avidin-biotin complex immunoperoxidase method.in horses, african horsesickness virus (ahsv) exhibits marked tropism for certain microvascular endothelia and components of the mononuclear phagocyte system. in this study, the tropism of a field isolate of ahsv serotype 5 was studied in 24 chicken embryos. histopathology on embryonic tissues harvested with 12 hour intervals revealed progressive changes associated with endothelial damage. immunolabeling demonstrated viral antigens in the microvascular endothelium of the spleen, lungs, and the m ...201121441110
a competitive elisa for the detection of group-specific antibody to equine encephalosis virus.a polyclonal antibody-based, group-specific, competitive elisa (c-elisa) for the detection of antibodies to equine encephalosis virus (eev) was developed. the assay measures the competition between a specific guinea pig antiserum and a test serum, for a pre-titrated eev antigen. the c-elisa detected antibodies to the seven known eev serotypes. reference antisera raised against other arboviruses did not cross react with eev antigen. negative sera from horses in the united kingdom were used to est ...201121458496
serotype specific primers and gel-based rt-pcr assays for 'typing' african horse sickness virus: identification of strains from africa.african horse sickness is a devastating, transboundary animal disease, that is 'listed' by the office international des epizooties (oie). although attenuated, inactivated and subunit vaccines have been developed for african horse sickness virus (ahsv), these are serotype-specific and their effective deployment therefore relies on rapid and reliable identification of virus type. ahsv serotype is controlled by the specificity of interactions between neutralising antibodies, and components of the o ...201122028787
african horse sickness.african horse sickness (ahs) is a reportable, noncontagious, arthropod-borne viral disease that results in severe cardiovascular and pulmonary illness in horses. ahs is caused by the orbivirus african horse sickness virus (ahsv), which is transmitted primarily by culicoides imicola in africa; potential vectors outside of africa include culicoides variipennis and biting flies in the genera stomoxys and tabanus. infection with ahsv has a high mortality rate. quick and accurate diagnosis can help p ...201123705175
use of real-time quantitative reverse transcription polymerase chain reaction for the detection of african horse sickness virus replication in culicoides imicola.despite its important role as vector for african horse sickness virus (ahsv), very little information is available on the dissemination of this virus in culicoides (avaritia) imicola kieffer (diptera: ceratopogonidae). this study reports on the applicability of a real-time quantitative reverse transcription polymerase chain reaction (rt-qpcr) to detect ahsv in dissected midges. a total of 96 midges were fed on ahsv-infected blood, after which one test group was dissected into head/thorax and abd ...201123327218
structural insight into african horsesickness virus infection.african horsesickness (ahs) is a devastating disease of horses. the disease is caused by the double-stranded rna-containing african horsesickness virus (ahsv). using electron cryomicroscopy and three-dimensional image reconstruction, we determined the architecture of an ahsv serotype 4 (ahsv-4) reference strain. the structure revealed triple-layered ahs virions enclosing the segmented genome and transcriptase complex. the innermost protein layer contains 120 copies of vp3, with the viral polymer ...201222593166
risk of introducing african horse sickness virus into the netherlands by international equine movements.african horse sickness (ahs) is a vector-borne viral disease of equines that is transmitted by culicoides spp. and can have severe consequences for the horse industry in affected territories. a study was performed to assess the risk of introducing ahs virus (ahsv) into the netherlands (p_ahs) by international equine movements. the goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and ...201222341773
utilization of cellulose microcapillary tubes as a model system for culturing and viral infection of mammalian cells.cryofixation by high-pressure freezing (hpf) and freeze substitution (fs) gives excellent preservation of intracellular membranous structures, ideal for ultrastructural investigations of virus infected cells. conventional sample preparation methods of tissue cultured cells can however disrupt the association between neighboring cells or of viruses with the plasma membrane, which impacts upon the effectiveness whereby virus release from cells can be studied. we established a system for virus infe ...201222865476
bluetongue virus genetic and phenotypic diversity: towards identifying the molecular determinants that influence virulence and transmission potential.bluetongue virus (btv) is the prototype member of the orbivirus genus in the family reoviridae and is the aetiological agent of the arthropod transmitted disease bluetongue (bt) that affects both ruminant and camelid species. the disease is of significant global importance due to its economic impact and effect on animal welfare. bluetongue virus, a dsrna virus, evolves through a process of quasispecies evolution that is driven by genetic drift and shift as well as intragenic recombination. quasi ...201222835527
an african horse sickness virus serotype 4 recombinant canarypox virus vaccine elicits specific cell-mediated immune responses in horses.a recombinant canarypox virus vectored vaccine co-expressing synthetic genes encoding outer capsid proteins, vp2 and vp5, of african horse sickness virus (ahsv) serotype 4 (alvac(®)-ahsv4) has been demonstrated to fully protect horses against homologous challenge with virulent field virus. guthrie et al. (2009) detected weak and variable titres of neutralizing antibody (ranging from <10 to 40) 8 weeks after vaccination leading us to hypothesize that there could be a participation of cell mediate ...201222763149
sustained high-throughput polymerase chain reaction diagnostics during the european epidemic of bluetongue virus serotype 8.a real-time reverse transcription polymerase chain reaction assay (pcr test) based on genome segment 10 of bluetongue virus (btv) was developed. the pcr test consists of robotized viral rna isolation from blood samples and an all-in-one method including initial denaturation of genomic double-stranded rna, reverse transcription polymerase chain reaction (rt-pcr), and real-time detection and analysis. reference strains of the 24 recognized btv serotypes, isolates from different years, and geograph ...201222529113
virus-specific cd8⁺ t-cells detected in pbmc from horses vaccinated against african horse sickness virus.african horsesickness (ahs) is an infectious but noncontagious viral disease affecting all species of equidae. the recall immune response of ahsv naïve horses immunised with an attenuated african horsesickness virus serotype 4 (ahsv4) was characterised using immune assays including elispot, real-time pcr (qpcr) and flow cytometry. the recall immune response detected in pbmc isolated from three inoculated horses showed an upregulation of circulating b lymphocytes that correlated with elevated il- ...201222365333
history of orbivirus research in south africa.in the early colonial history of south africa, horses played an important role, both in general transportation and in military operations. frequent epidemics of african horsesickness (ahs) in the 18th century therefore severely affected the economy. the first scientific research on the disease was carried out by alexander edington (1892), the first government bacteriologist of the cape colony, who resolved the existing confusion that reigned and established its identity as a separate disease. bl ...201223327123
passive transfer and rate of decay of maternal antibody against african horse sickness virus in south african thoroughbred foals.african horse sickness is an insect-transmitted, noncontagious disease of equids caused by african horse sickness virus (ahsv). mortality can exceed 90% in fully susceptible horse populations. a live-attenuated (modified live) cell-culture-adapted (mlv) polyvalent ahsv vaccine is widely used to control african horse sickness in endemic areas in southern africa. field studies detailing antibody responses of vaccinated horses are lacking.201323294121
african horse sickness in naturally infected, immunised horses.to determine whether subclinical cases, together with clinical cases, of african horse sickness (ahs) occur in immunised horses in field conditions, whole blood samples were collected and rectal temperatures recorded weekly from 50 nooitgedacht ponies resident in open camps at the faculty of veterinary science, university of pretoria, onderstepoort, during 2008-2010. the samples were tested for the presence of african horse sickness virus (ahsv) rna by a recently developed real-time rt-pcr. it w ...201322612775
serotype- and serogroup-specific detection of african horsesickness virus using phage displayed chicken scfvs for indirect double antibody sandwich elisas.there is an ongoing need for standardized, easily renewable immunoreagents for detecting african horsesickness virus (ahsv). two phage displayed single-chain variable fragment (scfv) antibodies, selected from a semi-synthetic chicken antibody library, were used to develop double antibody sandwich enzyme-linked immunosorbent assays (das-elisas) to detect ahsv. in the das-elisas, the scfv previously selected with directly immobilized ahsv-3 functioned as a serotype-specific reagent that recognized ...201323388433
ns1 is a key protein in the vaccine composition to protect ifnar(-/-) mice against infection with multiple serotypes of african horse sickness virus.african horse sickness virus (ahsv) belongs to the genus orbivirus. we have now engineered naked dnas and recombinant modified vaccinia virus ankara (rmva) expressing vp2 and ns1 proteins from ahsv-4. ifnar((-/-)) mice inoculated with dna/rmva-vp2,-ns1 from ahsv-4 in an heterologous prime-boost vaccination strategy generated significant levels of neutralizing antibodies specific of ahsv-4. in addition, vaccination stimulated specific t cell responses against the virus. the vaccine elicited parti ...201323894615
multiple large foreign protein expression by a single recombinant baculovirus: a system for production of multivalent vaccines.baculovirus expression system offers the advantage of expression of several large proteins simultaneously by a single recombinant virus. to date, expression of multiple large (>100kda) proteins has been hampered by the need to generate large constructs and repeat use of homologous sequence and promoter. the development of multi-loci baculovirus expression system overcomes these issues by enabling the recombination of large foreign sequences into different regions of the genome. in this paper, we ...201323872366
recovery of african horse sickness virus from synthetic rna.african horse sickness virus (ahsv) is an insect-vectored emerging pathogen of equine species. ahsv (nine serotypes) is a member of the genus orbivirus, with a morphology and coding strategy similar to that of the type member, bluetongue virus. however, these viruses are distinct at the genetic level, in the proteins they encode and in their pathobiology. ahsv infection of horses is highly virulent with a mortality rate of up to 90 %. ahsv is transmitted by culicoides, a common european insect, ...201323860489
outbreak investigation and molecular characterization of african horse sickness virus circulating in selected areas of ethiopia.the study was conducted from june 2011 to may 2012 in central, northern and western parts of ethiopia to investigate and identify circulating serotypes of african horse sickness virus (ahsv). the indigenous knowledge of equine owners about ahs in the study areas was assessed and also the retrospective data of ahs outbreaks for 2011 were analyzed. whole blood samples were collected for virus isolation and serotyping from diseased horses and mules showing typical signs of the ahs. virus isolation ...201323567554
diagnostic accuracy of a duplex real-time reverse transcription quantitative pcr assay for detection of african horse sickness virus.blood samples collected from 503 suspect cases of african horse sickness (ahs) and another 503 from uninfected, unvaccinated south african horses, as well as 98 samples from horses from an ahs free country, were tested with an ahs virus (ahsv) specific duplex real-time reverse transcription quantitative pcr (rt-qpcr) assay and virus isolation (vi). the diagnostic sensitivity and specificity of this ahsv rt-qpcr assay and vi were estimated using a 2-test 2-population bayesian latent class model w ...201323291102
outbreaks of african horse sickness in senegal, and methods of control of the 2007 epidemic.since first being detected in nigeria in january 2007, african horse sickness virus serotype 2 (ahsv-2) has spread throughout the northern hemisphere, and was first reported in senegal. a retrospective study was conducted from december 2009 to april 2010 using data collected in the field combined with information available at the direction of veterinary services. the epidemic started in the dakar region with two outbreaks in march and june 2007, respectively, and spread in several parts of the c ...201323223002
barcoding of biting midges in the genus culicoides: a tool for species determination.biting midges of the genus culicoides (diptera: ceratopogonidae) are insect vectors of economically important veterinary diseases such as african horse sickness virus and bluetongue virus. however, the identification of culicoides based on morphological features is difficult. the sequencing of mitochondrial cytochrome oxidase subunit i (coi), referred to as dna barcoding, has been proposed as a tool for rapid identification to species. hence, a study was undertaken to establish dna barcodes for ...201323106166
development and evaluation of a sybr green real-time rt-pcr assay for evaluation of cytokine gene expression in horse.cytokine secretion is one of the main mechanisms by which the immune system is regulated in response to pathogens. therefore, the measurement of cytokine expression is fundamental to characterizing the immune response to infections. real-time quantitative reverse transcriptase-polymerase chain reaction (rt-qpcr) is widely used to measure cytokine mrna levels, but assay conditions should be properly evaluated before analyzing important equine infections through relative quantification of gene exp ...201323103121
characterizing the species composition of european culicoides vectors by means of the köppen-geiger climate classification.biting midges of the genus culicoides spp. (diptera: ceratopogonidae) are vectors for the bluetongue virus, the african horse sickness virus and the recently emerged schmallenberg virus. here, species of the c. obsoletus complex, the c. pulicaris complex and c. imicola were considered. the objective was to compile a map of these culicoides species and their relation to the popular climate classification defined by wladimir köppen and rudolf geiger to provide a quick view on the species compositi ...201324267276
enhanced arbovirus surveillance with deep sequencing: identification of novel rhabdoviruses and bunyaviruses in australian mosquitoes.viral metagenomics characterizes known and identifies unknown viruses based on sequence similarities to any previously sequenced viral genomes. a metagenomics approach was used to identify virus sequences in australian mosquitoes causing cytopathic effects in inoculated mammalian cell cultures. sequence comparisons revealed strains of liao ning virus (reovirus, seadornavirus), previously detected only in china, livestock-infecting stretch lagoon virus (reovirus, orbivirus), two novel dimarhabdov ...201324314645
measurement of the infection and dissemination of bluetongue virus in culicoides biting midges using a semi-quantitative rt-pcr assay and isolation of infectious virus.culicoides biting midges (diptera: ceratopogonidae) are the biological vectors of globally significant arboviruses of livestock including bluetongue virus (btv), african horse sickness virus (ahsv) and the recently emerging schmallenberg virus (sbv). from 2006-2009 outbreaks of btv in northern europe inflicted major disruption and economic losses to farmers and several attempts were made to implicate palaearctic culicoides species as vectors. results from these studies were difficult to interpre ...201323940643
first detection of leishmania infantum (kinetoplastida: trypanosomatidae) in culicoides spp. (diptera: ceratopogonidae).culicoides (diptera: ceratopogonidae) species are known to be the vectors of bluetongue virus and african horses sickness virus (ahsv) in different areas of the world. nevertheless, other researchers have hypothesized that these arthropods could be involved in the transmission of other pathogens such as schmallenberg virus, plasmodium and leishmania parasites. identification of the culicoides' potential vector competence is crucial in understanding the worldwide culicoides/leishmania life cycle.201424460752
seasonal dynamics of culicoides (diptera: ceratopogonidae) biting midges, potential vectors of african horse sickness and bluetongue viruses in the niayes area of senegal.the african horse sickness epizootic in senegal in 2007 caused considerable mortality in the equine population and hence major economic losses. the vectors involved in the transmission of this arbovirus have never been studied specifically in senegal. this first study of the spatial and temporal dynamics of the culicoides (diptera: ceratopogonidae) species, potential vectors of african horse sickness in senegal, was conducted at five sites (mbao, parc hann, niague, pout and thies) in the niayes ...201424690198
tibet orbivirus, a novel orbivirus species isolated from anopheles maculatus mosquitoes in tibet, china.the genus orbivirus includes a number of important pathogenic viruses, including bluetongue virus (btv), african horse sickness virus (ahsv), and epizootic hemorrhagic disease virus (ehdv). in this study we describe the isolation and characterization of an orbivirus strain isolated from anopheles maculatus mosquitoes collected in tibet, china.201424533145
real time rt-pcr assays for detection and typing of african horse sickness virus.although african horse sickness (ahs) can cause up to 95% mortality in horses, naïve animals can be protected by vaccination against the homologous ahsv serotype. genome segment 2 (seg-2) encodes outer capsid protein vp2, the most variable of the ahsv proteins. vp2 is also a primary target for ahsv specific neutralising antibodies, and consequently determines the identity of the nine ahsv serotypes. in contrast vp1 (the viral polymerase) and vp3 (the sub-core shell protein), encoded by seg-1 and ...201424721971
serological response of foals to polyvalent and monovalent live-attenuated african horse sickness virus vaccines.african horse sickness (ahs) is typically a highly fatal disease in susceptible horses and vaccination is currently used to prevent the occurrence of disease in endemic areas. similarly, vaccination has been central to the control of incursions of african horse sickness virus (ahsv) into previously unaffected areas and will likely play a significant role in any future incursions. horses in the ahsv-infected area in south africa are vaccinated annually with a live-attenuated (modified-live virus ...201424814557
study of the virulence of serotypes 4 and 9 of african horse sickness virus in ifnar(-/-), balb/c and 129 sv/ev mice.african horse sickness virus (ahsv) is a double-stranded rna virus which belongs to the family reoviridae, genus orbivirus. recent studies have focused on the interferon-α/β receptor knock-out mice (ifnar(-/-)) as a small animal laboratory for the development of ahsv vaccines. the aim of this work was to study in vivo the virulence of two strains of ahsv and to compare the outcome of the infection of three mouse strains. to address this, ahsv serotypes 4 (ahsv-4) and 9 (ahsv-9) were inoculated s ...201425458420
development of a real time polymerase chain reaction assay for equine encephalosis virus.equine encephalosis virus (eev) is the cause of equine encephalosis. the disease is similar to mild forms of african horse sickness (ahs) and the two diseases are easily confused. laboratory identification and serotyping of eev is based on viral isolation in bhk-21 cells and a viral plaque inhibition neutralisation test. these procedures are time-consuming and therefore a more rapid diagnostic assay for eev that can distinguish eev from african horse sickness virus (ahsv) infections was develope ...201424161811
culicoides species abundance and potential over-wintering of african horse sickness virus in the onderstepoort area, gauteng, south africa.in south africa, outbreaks of african horse sickness (ahs) occur in summer; no cases are reported in winter, from july to september. the ahs virus (ahsv) is transmitted almost exclusively by culicoides midges (diptera: ceratopogonidae), of which culicoides imicola is considered to be the most important vector. the over-wintering mechanism of ahsv is unknown. in this study, more than 500 000 culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals be ...201425686125
comparative ultrastructural characterization of african horse sickness virus-infected mammalian and insect cells reveals a novel potential virus release mechanism from insect cells.african horse sickness virus (ahsv) is an arbovirus capable of successfully replicating in both its mammalian host and insect vector. where mammalian cells show a severe cytopathic effect (cpe) following ahsv infection, insect cells display no cpe. these differences in cell death could be linked to the method of viral release, i.e. lytic or non-lytic, that predominates in a specific cell type. active release of ahsv, or any related orbivirus, has, however, not yet been documented from insect cel ...201424347494
vaccination of mice with a modified vaccinia ankara (mva) virus expressing the african horse sickness virus (ahsv) capsid protein vp2 induces virus neutralising antibodies that confer protection against ahsv upon passive immunisation.in previous studies we showed that a recombinant modified vaccinia ankara (mva) virus expressing the protein vp2 of ahsv serotype 4 (mva-vp2) induced virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (ifnar-/-) against challenge. we continued these studies and determined, in the ifnar-/- mouse model, whether the antibody responses induced by mva-vp2 vaccination play a key role in protection against ahsv. thus, groups of mice were vaccinated with ...201424333835
vaccination of horses with a recombinant modified vaccinia ankara virus (mva) expressing african horse sickness (ahs) virus major capsid protein vp2 provides complete clinical protection against challenge.african horse sickness virus (ahsv) is an arthropod-borne pathogen that infects all species of equidae and causes high mortality in horses. previously, a recombinant modified vaccinia ankara (mva) virus expressing the protein vp2 of ahsv serotype 4 was shown to induce virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (ifnar -/-) against virulent ahsv challenge. this study builds on the previous work, examining the protective efficacy of mva-vp2 v ...201424837765
<i>culicoides</i> species abundance and potential over-wintering of african horse sickness virus in the onderstepoort area, gauteng, south africa.in south africa, outbreaks of african horse sickness (ahs) occur in summer; no cases are reported in winter, from july to september. the ahs virus (ahsv) is transmitted almost exclusively by culicoides midges (diptera: ceratopogonidae), of which culicoides imicola is considered to be the most important vector. the over-wintering mechanism of ahsv is unknown. in this study, more than 500 000 culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals be ...201428235307
immunogenicity of recombinant vp2 proteins of all nine serotypes of african horse sickness virus.african horse sickness (ahs) is an equine disease with a mortality of up to 90% for susceptible horses. the causative agent ahs virus (ahsv) is transmitted by species of culicoides. ahsv serogroup within the genus orbivirus of the reoviridae family consists of nine serotypes that show no or very limited cross-neutralization. of the seven structural proteins (vp1-vp7) of ahsv, vp2 is the serotype specific protein, and the major target for neutralizing antibodies. in this report, recombinant vp2 p ...201425045805
susceptibility of culicoides species biting midges to deltamethrin-treated nets as determined under laboratory and field conditions in the balearic islands, spain.culicoides latreille (diptera: ceratopogonidae) are vectors of several arboviruses, including bluetongue virus (btv) and african horse sickness virus (ahsv), which cause diseases in, respectively, sheep and cattle, and horses, and have economic repercussions mainly as a result of trade restrictions. insecticides can be used to reduce vector populations and hence the spread of disease. despite the economic importance of these diseases, relatively few studies have evaluated the efficacy of commerc ...201424890642
factors that affect the intracellular localization and trafficking of african horse sickness virus core protein, vp7.african horse sickness virus (ahsv) vp7 is the major core protein of the virion. apart from its role in virus assembly, vp7 forms crystalline-like particles during infection and when expressed in insect cells. the aim of this study was to investigate the process of vp7 crystalline-like particle formation. the intracellular distribution of vp7 was characterized in different systems and the association of vp7 with virus factories during ahsv infection was investigated. it was shown that the majori ...201424889247
african horse sickness outbreaks caused by multiple virus types in ethiopia.african horse sickness (ahs) is associated with high morbidity and mortality in equids, especially horses. a retrospective analysis was carried out concerning 737 ahs outbreaks that occurred during 2007-2010 in ethiopia. a total of ten outbreaks were investigated in the study period. all four forms of the disease (pulmonary, cardiac, horse sickness fever and the combined form) were observed, with the cardiac form being the most prevalent. multiple african horse sickness virus serotypes (ahsv-2, ...201423083078
analysis of murine b-cell epitopes on bluetongue virus 12 nonstructural protein 1.the bluetongue virus (btv) ns1 protein is one of the major proteins synthesized during btv infection and is responsible for the generation of virus-specific tubules. although some functional and structural studies on the btv ns1 protein have been reported, there have been no reports describing the linear b-cell epitopes recognized by humoral immune responses published to date. in this study, 25 btv12 ns1-reactive monoclonal antibodies (mabs) and polyclonal antisera (polyclonal antibodies, pabs) ...201525343975
a quantitative real-time reverse transcription pcr (qrt-pcr) assay to detect genome segment 9 of all 26 bluetongue virus serotypes.bluetongue (bt) is an arboviral disease, which can often be fatal in naïve sheep and white tailed deer, but is usually less severe, or unapparent in other ruminants. twenty-six bluetongue virus (btv) serotypes have been recognised so far, two of which (btv-25 and btv-26) were recently identified by phylogenetic comparisons of genome-segment/outer-capsid protein vp2 (subsequently confirmed by serological 'virus-neutralisation' assays). rapid, sensitive, reliable and quantitative diagnostic-assays ...201525486080
inactivated and adjuvanted vaccine for the control of the african horse sickness virus serotype 9 infection: evaluation of efficacy in horses and guinea-pig model.african horse sickness (ahs) is a non-contagious viral disease of solipeds transmitted by culicoides. the disease is endemic in most african countries. past experience has shown that italy is a country exposed to emerging infectious diseases endemic to africa; an incursion of ahs virus together with the widespread presence of culicoides vectors could be the cause of a serious epidemic emergency. a live attenuated vaccine containing seven of the nine viral serotypes, serotype 5 and 9 are excluded ...201523564590
update on viral diseases of the equine respiratory tract.many viral agents have been associated with respiratory disease of the horse. the most important viral causes of respiratory disease in horses are equine influenza and the equine alphaherpesviruses. agents such as equine viral arteritis virus, african horse sickness virus, and hendra virus establish systemic infections. clinical signs of disease resulting from infection with these agents can manifest as respiratory disease, but the respiratory tract is not the major body system affected by these ...201525648568
antiserum from mice vaccinated with modified vaccinia ankara virus expressing african horse sickness virus (ahsv) vp2 provides protection when it is administered 48h before, or 48h after challenge.previous studies show that a recombinant modified vaccinia ankara (mva) virus expressing vp2 of ahsv serotype 4 (mva-vp2) induced virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (ifnar -/-) against challenge. follow up experiments indicated that passive transfer of antiserum, from mva-vp2 immune donors to recipient mice 1h before challenge, conferred complete clinical protection and significantly reduced viraemia. these studies have been extend ...201525643968
geographic range of vector-borne infections and their vectors: the role of african wildlife.the role of african wildlife in the occurrence of vector-borne infections in domestic animals has gained renewed interest as emerging and re-emerging infections occur worldwide at an increasing rate. in africa, biodiversity conservation and the expansion of livestock production have increased the risk of transmitting vector-borne infections between wildlife and livestock. the indigenous african pathogens with transboundary potential, such as rift valley fever virus, african horse sickness virus, ...201526470454
african horse sickness outbreaks in namibia from 2006 to 2013: clinical, pathological and molecular findings.african horse sickness (ahs) is a vector‑borne viral disease of equids, endemic in sub‑saharan africa. this article reports the clinic‑pathological and laboratory findings observed in the framework of passive surveillance during the ahs outbreaks which occurred in namibia between 2006 and 2013. this study was conducted in the framework of the collaboration among the istituto zooprofilattico sperimentale dell'abruzzo e del molise (teramo, italy), the namibian ministry of agriculture water and for ...201526129663
protection of horses against culicoides biting midges in different housing systems in switzerland.species belonging to the culicoides complexes (diptera, ceratopogonidae), obsoletus and pulicaris, in switzerland, are potential vectors of both bluetongue virus (btv) and african horse sickness virus (ahsv). the epidemic of btv in 2006 and 2007 in europe has highlighted the risk of introduction and spread of vector-borne diseases in previously non-endemic areas. as a measure of prevention, as part of an integrated control programme in the event of an outbreak of african horse sickness (ahs), it ...201525935291
orbivirus detection from culicoides collected on african horse sickness outbreaks in namibia.african horse sickness (ahs), a non-contagious infectious disease caused by a rna virus in the orbivirus genus within the reoviridae family affecting all equids, is endemic in sub-saharan africa. the virus is transmitted by some species of biting midges in the genus culicoides (diptera: ceratopogonidae). in april 2011, 8 culicoides collections were performed in 6 districts of 4 regions of the republic of namibia (africa), all within a 400 km radious from the capital windhoek. six farms - khomas ...201525842209
virus uncoating is required for apoptosis induction in cultured mammalian cells infected with african horse sickness virus.infection of cultured mammalian cells with african horse sickness virus (ahsv) is known to induce cell death. to date, the trigger(s) of this response, the apoptotic pathways activated during ahsv infection and the functional consequences of apoptosis on the virus replication cycle have yet to be characterized. this study demonstrated that extracellular treatment of bhk-21 cells with both of the ahsv4 outer capsid proteins, vp2 and vp5, was sufficient to trigger apoptosis. whether steps in ahsv4 ...201525783475
consensus sequence of 27 african horse sickness virus genomes from viruses collected over a 76-year period (1933 to 2009).we announce the complete consensus genome sequence of 27 african horse sickness viruses, representing all nine african horse sickness virus (ahsv) serotypes from historical and recent isolates collected over a 76-year period (1933 to 2009). the data set includes the sequence of the virulent office international des epizooties ahsv reference strains which are not adapted to cell culture.201526358586
identification of cd8 t cell epitopes in vp2 and ns1 proteins of african horse sickness virus in ifnar(-/-) mice.african horse sickness virus (ahsv) is an orbivirus of the family reoviridae that causes severe pathology in equids. previous work in our laboratory showed the presence of ahsv-specific cd8(+) t cells in mice immunized with recombinant modified vaccinia ankara (rmva) expressing vp2 and ns1 proteins. in the present work, we selected potential cd8 t cell epitopes (mhc-class i binding peptides) for the 129 mouse strain from the vp2 and ns1 proteins of ahsv-4, using a combination of four epitope pre ...201526272673
development of three triplex real-time reverse transcription pcr assays for the qualitative molecular typing of the nine serotypes of african horse sickness virus.blood samples collected as part of routine diagnostic investigations from south african horses with clinical signs suggestive of african horse sickness (ahs) were subjected to analysis with an ahs virus (ahsv) group specific reverse transcription quantitative polymerase chain reaction (ahsv rt-qpcr) assay and virus isolation (vi) with subsequent serotyping by plaque inhibition (pi) assays using ahsv serotype-specific antisera. blood samples that tested positive by ahsv rt-qpcr were then selected ...201526232526
complete genome sequences of four african horse sickness virus strains from a commercial tetravalent live attenuated vaccine.this is a report of the complete genome sequences of plaque-selected isolates of each of the four virus strains included in a south african commercial tetravalent african horse sickness attenuated live virus vaccine.201526607890
zoonotic and emerging orbivirus infections.many novel emerging orbiviruses have been isolated in the past 15 years. important viruses include peruvian horse sickness virus (phsv) and yunnan orbivirus (yuov), pathogens of equids which were originally isolated almost simultaneously from 1997 to 1999 in the people's republic of china, australia and peru. yuov has also been isolated from cattle, sheep and a dog. the isolation of yuovfrom a dog is not the first case of an orbivirus being isolated from a carnivore. bluetongue virus and african ...201526601440
african horse sickness.african horse sickness (ahs) is a devastating disease of equids caused by an arthropod-borne virus belonging to the reoviridae family, genus orbivirus. it is considered a major health threat for horses in endemic areas in sub-saharan africa. african horse sickness virus (ahsv) repeatedly caused large epizootics in the mediterranean region (north africa and southern europe in particular) as a result of trade in infected equids. the unexpected emergence of a closely related virus, the bluetongue v ...201526601437
characterising non-structural protein ns4 of african horse sickness virus.african horse sickness is a serious equid disease caused by the orbivirus african horse sickness virus (ahsv). the virus has ten double-stranded rna genome segments encoding seven structural and three non-structural proteins. recently, an additional protein was predicted to be encoded by genome segment 9 (seg-9), which also encodes vp6, of most orbiviruses. this has since been confirmed in bluetongue virus and great island virus, and the non-structural protein was named ns4. in this study, in si ...201525915516
vector competence of culicoides for arboviruses: three major periods of research, their influence on current studies and future directions.the spectacular and unprecedented outbreaks of bluetongue virus (btv) that have occurred in europe since 1998 have led to increased interest in those factors that determine competence of culicoides biting midges (diptera: ceratopogonidae) for arboviruses. in this review the authors critically examine three major periods of research into the biological transmission by culicoides of two economically important arboviruses ofthefamily reoviridae: african horse sicknessvirus (ahsv) and btv. first the ...201526470451
complete genome sequences of the three african horse sickness virus strains from a commercial trivalent live attenuated vaccine.this is a report of the complete genome sequences of plaque-selected isolates of each of the three virus strains included in a south african commercial trivalent african horse sickness attenuated live virus vaccine.201526294618
characterization of a second open reading frame in genome segment 10 of bluetongue virus.viruses have often evolved overlapping reading frames in order to maximize their coding capacity. until recently, the segmented dsrna genome of viruses of the orbivirus genus was thought to be monocistronic, but the identification of the bluetongue virus (btv) ns4 protein changed this assumption. a small orf in segment 10, overlapping the ns3 orf in the +1 position, is maintained in more than 300 strains of the 27 different btv serotypes and in more than 200 strains of the phylogenetically relat ...201526290332
vp2 exchange and ns3/ns3a deletion in african horse sickness virus (ahsv) in development of disabled infectious single animal vaccine candidates for ahsv.african horse sickness virus (ahsv) is a virus species in the genus orbivirus of the family reoviridae. there are nine serotypes of ahsv showing different levels of cross neutralization. ahsv is transmitted by species of culicoides biting midges and causes african horse sickness (ahs) in equids, with a mortality rate of up to 95% in naive horses. ahs has become a serious threat for countries outside africa, since endemic culicoides species in moderate climates appear to be competent vectors for ...201526063433
circadian activity of culicoides oxystoma (diptera: ceratopogonidae), potential vector of bluetongue and african horse sickness viruses in the niayes area, senegal.culicoides biting midges (diptera: ceratopogonidae) are important vectors of arboviruses in africa. culicoides oxystoma has been recently recorded in the niayes region of senegal (west africa) and its high abundance on horses suggests a potential implication in the transmission of the african horse sickness virus in this region. this species is also suspected to transmit bluetongue virus to imported breeds of sheep. little information is available on the biology and ecology of culicoides in afri ...201526002826
culicoides (diptera: ceratopogonidae) midges, the vectors of african horse sickness virus--a host/vector contact study in the niayes area of senegal.african horse sickness (ahs) is an equine disease endemic to senegal. the african horse sickness virus (ahsv) is transmitted to the mammalian hosts by midges of the culicoides latreille genus. during the last epizootic outbreak of ahs in senegal in 2007, 1,169 horses died from this disease entailing an estimated cost of 1.4 million euros. in spite of the serious animal health and economic implications of ahs, very little is known about determinants involved in transmission such as contact betwee ...201525604465
can insecticide-treated netting provide protection for equids from culicoides biting midges in the united kingdom?biting midges of the genus culicoides latreille, 1809 (diptera: ceratopogonidae) cause a significant biting nuisance to equines and are responsible for the biological transmission of african horse sickness virus (ahsv). while currently restricted in distribution to sub-saharan africa, ahsv has a history of emergence into southern europe and causes one of the most lethal diseases of horses and other species of equidae. in the event of an outbreak of ahsv, the use of insecticide treated nets (itns ...201526607993
a spatiotemporal model to assess the introduction risk of african horse sickness by import of animals and vectors in france.african horse sickness (ahs) is a major, culicoides-borne viral disease in equines whose introduction into europe could have dramatic consequences. the disease is considered to be endemic in sub-saharan africa. recent introductions of other culicoides-borne viruses (bluetongue and schmallenberg) into northern europe have highlighted the risk that ahs may arrive in europe as well. the aim of our study was to provide a spatiotemporal quantitative risk model of ahs introduction into france. the stu ...201526040321
delineation of the population genetic structure of culicoides imicola in east and south africa.culicoides imicola kieffer, 1913 is the main vector of bluetongue virus (btv) and african horse sickness virus (ahsv) in sub-saharan africa. understanding the population genetic structure of this midge and the nature of barriers to gene flow will lead to a deeper understanding of bluetongue epidemiology and more effective vector control in this region.201526704134
insight on the larval habitat of afrotropical culicoides latreille (diptera: ceratopogonidae) in the niayes area of senegal, west africa.certain biting midges species of the genus culicoides (diptera: ceratopogonidae) are vectors of virus to livestock worldwide. culicoides larval ecology has remained overlooked because of difficulties to identify breeding sites, methodological constraints to collect samples and lack of morphological tools to identify field-collected individuals to the species level. after the 2007 unforeseen outbreaks of african horse sickness virus (ahsv) in senegal (west africa), there is a need to identify sui ...201627549191
immune gene expression profiling of pbmc isolated from horses vaccinated with attenuated african horsesickness virus serotype 4.development of african horsesickness (ahs) subunit vaccines will have to include a rational approach that uses knowledge of how the virus interacts with the host immune system. the global in vivo immune response induced by attenuated ahsv serotype 4 in horses was characterised using transcriptome sequencing. pbmc were collected with 24h intervals for four days after inoculation and four days after a second boost, 21 days later. transcriptome data were normalised to the day 0 naïve transcriptome ...201626382058
culicoides species composition and environmental factors influencing african horse sickness distribution at three sites in namibia.african horse sickness (ahs) is one of the most lethal infectious, non-contagious, vector-borne disease of equids. the causative agent, african horse sickness virus (ahsv) is transmitted via culicoides midges (diptera: ceratopogonidae). ahs is endemic to namibia but detailed studies of culicoides communities and influencing environmental parameters are limited. this study aims to determine the culicoides species composition at three different sites and to assess environmental parameters influenc ...201627491343
identification of suitable areas for african horse sickness virus infections in spanish equine populations.african horse sickness (ahs) is one of the most important vector-borne viral infectious diseases of equines, transmitted mainly by culicoides spp. the re-emergence of culicoides-borne diseases in europe, such as the recent bluetongue (bt) or schmallenberg outbreaks, has raised concern about the potential re-introduction and further spread of ahs virus (ahsv) in europe. spain has one of the largest european equine populations. in addition, its geographical, environmental and entomological conditi ...201625476549
development of a microsphere-based immunoassay for serological detection of african horse sickness virus and comparison with other diagnostic techniques.african horse sickness (ahs) is a viral disease that causes high morbidity and mortality rates in susceptible equidae and therefore significant economic losses. more rapid, sensitive and specific assays are required by diagnostic laboratories to support effective surveillance programmes. a novel microsphere-based immunoassay (luminex assay) in which beads are coated with recombinant ahs virus (ahsv) structural protein 7 (vp7) has been developed for serological detection of antibodies against vp7 ...201625693720
establishment of different plasmid only-based reverse genetics systems for the recovery of african horse sickness virus.in an effort to simplify and expand the utility of african horse sickness virus (ahsv) reverse genetics, different plasmid-based reverse genetics systems were developed. plasmids containing cdnas corresponding to each of the full-length double-stranded rna genome segments of ahsv-4 under control of a t7 rna polymerase promoter were co-transfected in cells expressing t7 rna polymerase, and infectious ahsv-4 was recovered. this reverse genetics system was improved by reducing the required plasmids ...201627657835
quantitative analysis of the probability of introducing equine encephalosis virus (eev) into the netherlands.equine encephalosis is a midge-borne viral disease of equines caused by equine encephalosis virus (eev, orbivirus, reoviridae), and closely related to african horse sickness virus (ahsv). eev and ahsv share common vectors and show similar transmission patterns. until now eev has caused outbreaks in africa and israel. this study aimed to provide insight in the probability of an eev outbreak in the netherlands caused by infected vectors or hosts, the contribution of potential source areas (risk re ...201627544251
african horse sickness virus infects bsr cells through macropinocytosis.cellular pathways involved in cell entry by african horse sickness virus (ahsv), a member of the orbivirus genus within the reoviridae family, have not yet been determined. here, we show that acidic ph is required for productive infection of bsr cells by ahsv-4, suggesting that the virus is likely internalized by an endocytic pathway. we subsequently analyzed the major endocytic routes using specific inhibitors and determined the consequences for ahsv-4 entry into bsr cells. the results indicate ...201627497184
development of a novel reverse transcription loop-mediated isothermal amplification assay for the rapid detection of african horse sickness virus.african horse sickness (ahs) is a disease of equids caused by african horse sickness virus (ahsv) and is transmitted by culicoides midges. ahs is endemic in sub-saharan africa, but during the past century, outbreaks of significant economic importance and elevated mortality have been recorded in northern african countries, the iberian and arabian peninsula, the middle east and the indian subcontinent. effective control combines the application of early warning systems, accurate laboratory diagnos ...201627484889
requirements and comparative analysis of reverse genetics for bluetongue virus (btv) and african horse sickness virus (ahsv).bluetongue virus (btv) and african horse sickness virus (ahsv) are distinct arthropod borne virus species in the genus orbivirus (reoviridae family), causing the notifiable diseases bluetongue and african horse sickness of ruminants and equids, respectively. reverse genetics systems for these orbiviruses with their ten-segmented genome of double stranded rna have been developed. initially, two subsequent transfections of in vitro synthesized capped run-off rna transcripts resulted in the recover ...201627368544
assembly of replication-incompetent african horse sickness virus particles: rational design of vaccines for all serotypes.african horse sickness virus (ahsv), an orbivirus in the reoviridae family with nine different serotypes, causes devastating disease in equids. the virion particle is composed of seven proteins organized in three concentric layers, an outer layer made of vp2 and vp5, a middle layer made of vp7, and inner layer made of vp3 that encloses a replicase complex of vp1, vp4, and vp6 and a genome of 10 double-stranded rna segments. in this study, we sought to develop highly efficacious candidate vaccine ...201627279609
detection of african horse sickness virus in culicoides imicola pools using rt-qpcr.african horse sickness (ahs) is an infectious, non-contagious arthropod-borne disease of equids, caused by the african horse sickness virus (ahsv), an orbivirus of the reoviridae family. it is endemic in sub-saharan africa and thought to be the most lethal viral disease of horses. this study focused on detection of ahsv in culicoides imicola (diptera: ceratopogonidae) pools by the application of a rt-qpcr. midges were fed on ahsv-infected blood. a single blood-engorged female was allocated to po ...201627232141
evaluation of a transcription mediated amplification assay for detection of herpes simplex virus types 1 and 2 mrna in clinical specimens.herpes simplex viruses (hsv) are double-stranded dna human herpesviruses (hhvs) that have the capacity to cause significant morbidity and mortality in humans. like hhv5 (cytomegalovirus) and hhv8 (kaposi's sarcoma virus), hsv type 1 (hsv-1), and hsv type 2 (hsv-2) (hhv1, hhv2) selectively package certain viral messenger rnas inside mature virions, as well as expressing those mrnas in infected cells.201627175478
development of a luminex-based diva assay for serological detection of african horse sickness virus in horses.african horse sickness (ahs) is considered a fatal re-emergent vector-borne disease of horses. in the absence of any effective treatment for ahs, vaccination remains the most effective form of disease control. the new generation of vaccines, such as one based on purified, inactivated ahs virus (ahsv, serotype 4), which does not induce antibodies against non-structural protein 3 (ns3), enables the development of diagnostic methods that differentiate infected from vaccinated animals (diva assays). ...201627090377
african horse sickness virus serotype 4 antigens, vp1-1, vp2-2, vp4, vp7 and ns3, induce cytotoxic t cell responses in vitro.it was shown in a previous study that proliferating cd8+ t cells could be detected in immune horse peripheral blood mononuclear cells (pbmc) when stimulated with african horse sickness virus serotype 4 (ahsv4). in this study the cytotoxicity of cd8+ t cells were tested by using the fluorescent antigen-transfected target cells-cytotoxic t lymphocytes (fatt-ctl) assay, for both the virus and its individual proteins expressed in escherichia coli. this ctl assay measures the killing of viral protein ...201627063332
evaluation of in vitro methods for assessment of infection of australian culicoides spp. with bluetongue viruses.biting midges from the genus culicoides (diptera: ceratopogonidae) are the vectors of several globally important arboviruses that affect livestock. these include orbiviruses from the bluetongue virus (btv) and african horse sickness virus (ahsv) groups and members of the simbu serogroup of orthobunyaviruses, such as the recently emerged schmallenberg virus. in this article, the authors evaluate several methods for feeding wild‑caught australian culicoides on btv infected preparations of blood an ...201626741248
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