Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| the prevalence of different african horsesickness virus serotypes in the onderstepoort area near pretoria, during an outbreak of african horsesickness in south africa in 1995/1996. | during 1995/1996 parts of south africa experienced exceptionally high rainfall. large numbers of culicoides midges were seen and an outbreak of african horsesickness (ahs) followed. in the onderstepoort area, near pretoria in gauteng, a number of horses died of suspected ahs. virus isolation and typing was done from blood and/or organ samples of 21 suspected cases as well as from five zebra which were kept in the area. virus was isolated from 14 of the 21 suspected cases but not from the zebra. ... | 2000 | 10843324 |
| cloning and expression of the m5 rna segment encoding outer capsid vp5 of epizootic hemorrhagic disease virus japan serotype 2, ibaraki virus. | the complete nucleotide sequence of a cdna clone representing the m5 rna segment of epizootic hemorrhagic disease virus japan serotype 2 (ehdv-2), ibaraki virus, was determined. the m5 segment is 1641 base pairs long with the single open reading frame which predicts a polypeptide of 527 amino acids. the comparison of the amino acid sequence of the vp5 with those of ehdv-1, bluetongue virus serotype 10, and african horse sickness virus serotype 4 revealed that the protein shared 67%, 57% and 42% ... | 2000 | 10770603 |
| identification of antigenic regions on vp2 of african horsesickness virus serotype 3 by using phage-displayed epitope libraries. | vp2 is an outer capsid protein of african horsesickness virus (ahsv) and is recognized by serotype-discriminatory neutralizing antibodies. with the objective of locating its antigenic regions, a filamentous phage library was constructed that displayed peptides derived from the fragmentation of a cdna copy of the gene encoding vp2. peptides ranging in size from approximately 30 to 100 amino acids were fused with piii, the attachment protein of the display vector, fuse2. to ensure maximum diversit ... | 2000 | 10725425 |
| cloning, sequencing and expression of the gene that encodes the major neutralisation-specific antigen of african horsesickness virus serotype 9. | a marked improvement in the efficiency of cloning the large double stranded rna (dsrna) genome segments of african horsesickness virus (ahsv) was achieved when the dsrna polyadenylation step was carried out with undenatured rather than strand-separated dsrna. it is a prerequisite to use dsrna of very high purity because in the presence of even trace amounts of single stranded rna, the dsrna appears to be poorly polyadenylated as judged by its effectiveness as a template for oligo-dt-primed cdna ... | 2000 | 10713375 |
| african horse sickness in senegal: serotype identification and nucleotide sequence determination of segment s10 by rt-pcr. | 2000 | 10682696 | |
| effects of chlorine, iodine, and quaternary ammonium compound disinfectants on several exotic disease viruses. | the effects of three representative disinfectants, chlorine (sodium hypochlorite), iodine (potassium tetraglicine triiodide), and quaternary ammonium compound (didecyldimethylammonium chloride), on several exotic disease viruses were examined. the viruses used were four enveloped viruses (vesicular stomatitis virus, african swine fever virus, equine viral arteritis virus, and porcine reproductive and respiratory syndrome virus) and two non-enveloped viruses (swine vesicular disease virus (svdv) ... | 2000 | 10676896 |
| identification and differentiation of the nine african horse sickness virus serotypes by rt-pcr amplification of the serotype-specific genome segment 2. | this paper describes the first rt-pcr for discrimination of the nine african horse sickness virus (ahsv) serotypes. nine pairs of primers were designed, each being specific for one ahsv serotype. the rt-pcr was sensitive and specific, providing serotyping within 24 h. perfect agreement was recorded between the rt-pcr and virus neutralization for a coded panel of 56 ahsv reference strains and field isolates. serotyping was achieved successfully with live and formalin-inactivated ahsvs, with isola ... | 2000 | 10675421 |
| vector competence of selected south african culicoides species for the bryanston serotype of equine encephalosis virus. | equine encephalosis virus (eev) was recognized and described in the republic of south africa in 1967 and subsequent serological studies have shown this orbivirus to be both widespread and prevalent in southern africa. in the present study it was shown that wild-caught culicoides (avaritia) imicola kieffer (diptera: ceratopogonidae) can become infected with and permit the replication of the bryanston serotype of eev following membrane-feeding on infective blood containing 5.0 log10 plaque-forming ... | 1999 | 10608228 |
| [use of the immunoenzyme test elisa-ns3 to distinguish horses infected by african horsesickness virus from vaccinated horses]. | a vaccination protocol involving three horses, with five repeated injections of inactivated serotype 4 african horse sickness virus, was undertaken to determine a possible threshold for the appearance of antibodies against the non-structural protein ns3. using an indirect enzyme-linked immunosorbent assay, with the recombinant ns3 protein as an antigen, the authors detected a response to ns3 as of the second injection for the first horse and after four injections for the second horse. no respons ... | 1999 | 10588005 |
| african horse sickness in portugal: a successful eradication programme. | african horse sickness (ahs) was diagnosed for the first time in southern portugal in autumn 1989, following outbreaks in spain. ahs virus presence was confirmed by virus isolation and serotyping. an eradication campaign with four sanitary zones was set up by central veterinary services in close collaboration with private organizations. vaccination began on 6 october. in february 1990, vaccination was extended to all portuguese equines (170000 animals). there were 137 outbreaks on 104 farms: 206 ... | 1999 | 10579455 |
| immune responses in a horse inoculated with the vp2 gene of african horsesickness virus. | the ability of a dna vaccine to elicit an immune response in a horse was evaluated. the outer capsid protein vp2 of african horsesickness virus is known to elicit protective immunity in horses. reverse transcribed dna of the gene encoding vp2 was placed under the transcriptional control of the cytomegalovirus immediate-early enhancer/promoter and was injected on several occasions intramuscularly into a horse. low antibody levels could be detected by elisa. antibodies directed against vp2 alone w ... | 1999 | 10486832 |
| the use of chicken igy in a double antibody sandwich elisa for detecting african horsesickness virus. | an indirect sandwich elisa that can detect as little as 8 ng of african horsesickness virus (ahsv) was developed. viral antigen was captured from suspension using an immobilized monoclonal antibody specific for an epitope on vp7, a protein that is a major constituent of the virus core. egg-yolk derived chicken igy directed against ahsv (serotype 3) was used as the secondary antibody. since igy and mouse igg do not cross-react serologically, the secondary antibody was not labelled, but was instea ... | 1999 | 10396758 |
| antigenic profile of african horse sickness virus serotype 4 vp5 and identification of a neutralizing epitope shared with bluetongue virus and epizootic hemorrhagic disease virus. | african horse sickness virus (ahsv) causes a fatal disease in horses. the virus capsid is composed of a double protein layer, the outermost of which is formed by two proteins: vp2 and vp5. vp2 is known to determine the serotype of the virus and to contain the neutralizing epitopes. the biological function of vp5, the other component of the capsid, is unknown. in this report, ahsv vp5, expressed in insect cells alone or together with vp2, was able to induce ahsv-specific neutralizing antibodies. ... | 1999 | 10329555 |
| molecular analysis of the genome of chuzan virus, a member of the palyam serogroup viruses, and its phylogenetic relationships to other orbiviruses. | the nucleotide sequence of the entire genome of chuzan virus, which belongs to the palyam serogroup orbiviruses and causes congenital abnormalities of cattle, has been completed by analysis of the genes encoding minor core proteins (vp1, vp4 and vp6) and non-structural proteins (ns1, ns2 and ns3). the genome of chuzan virus is 18,915 bp in length and the coding capacity of its open reading frames is 6071 aa. comparative sequence analysis with other serogroups of the genus orbivirus indicated tha ... | 1999 | 10211963 |
| protein aggregation complicates the development of baculovirus-expressed african horsesickness virus serotype 5 vp2 subunit vaccines. | this paper describes the expression of a cloned african horsesickness virus (ahsv) serotype 5 vp2-gene by a baculovirus recombinant that was generated by the bac-to-bac system. immunization of horses with crude cell lysates containing recombinant baculovirus-expressed ahsv5 vp2 did induce neutralizing antibodies, but afforded only partial protection against virulent virus challenge. further analysis of partially protective crude cell lysates revealed that baculovirus-expressed ahsv5 vp2 was pred ... | 1998 | 10192846 |
| molecular characterization of double-stranded rna segments encoding the major capsid proteins of a palyam serogroup orbivirus that caused an epizootic of congenital abnormalities in cattle. | cdna cloning of the double-stranded rna genome of chuzan virus, a member of the palyam serogroup orbiviruses, was carried out and the complete nucleotide sequences of rna segments 2, 3, 6 and 7, encoding the major capsid proteins vp2, vp3, vp5 and vp7, respectively, were determined. the individual segments had single open reading frames and short inverted repeats adjacent to the conserved terminal sequences. comparative sequence analysis with other serogroups of the genus orbivirus suggested tha ... | 1999 | 9934703 |
| observations on african horse sickness in saudi arabia. | the present epidemiological status of african horse sickness in saudi arabia, as shown by seroconversion, virus isolation and clinical observation of sentinel horses is described. no african horse sickness virus activity was detected throughout the duration of the study (from november 1992 to march 1995). these findings support previous reports that african horse sickness is not endemic in saudi arabia. | 1998 | 9850549 |
| western immunoblotting as a method for the detection of african horse sickness virus protein-specific antibodies: differentiation between infected and vaccinated horses. | a western immunoblotting procedure has been developed for the detection of african horse sickness virus (ahsv) protein-specific antibody responses. this assay readily identifies antibodies specific for at least 4 distinct, ahsv proteins, including vp5, ns1, ns2 and ns3/ns3a. by using the ahsv non-structural proteins as 'markers', the western blotting procedure could be employed to provide a reliable means of discriminating between animals vaccinated with a purified, inactivated ahsv vaccine and ... | 1998 | 9785518 |
| use of reverse transcriptase-polymerase chain reaction (rt-pcr) and dot-blot hybridisation for the detection and identification of african horse sickness virus nucleic acids. | a coupled reverse transcriptase-polymerase chain reaction assay (rt-pcr) for the detection of african horse sickness virus (ahsv) dsrna, has been developed using genome segment 7 as the target template for primers. rna from isolates of all nine ahsv serotypes were readily detected. the potential inhibitory effects of either ethylene diamine tetra acetic acid (edta) or heparin on the rt-pcr were eliminated by washing blood samples before lysis of the red blood cells and storage. there was a close ... | 1998 | 9785517 |
| validation of elisa for the detection of african horse sickness virus antigens and antibodies. | the mortality rate in susceptible populations of horses during an epizootic of african horse sickness (ahs) may be in excess of 90%. rapid and reliable assays are therefore essential for the confirmation of clinical diagnoses and to enable control strategies to be implemented without undue delay. one of the major objectives of a recent european union funded project was the validation of newly developed diagnostic assays which are rapid, sensitive, highly reproducible and inexpensive, for the det ... | 1998 | 9785516 |
| application of an indirect fluorescent antibody assay for the detection of african horse sickness virus antibodies. | an indirect fluorescent antibody (ifa) technique was used to screen and quantify antibodies against african horse sickness virus (ahsv) in equine sera. results obtained with the ifa assay were compared directly with those obtained with standard complement fixation (cf) and virus neutralisation (vn) tests using horse sera from experimental studies and samples from the field. positive fluorescent antibody titres were detected from as early as 7 days after primary vaccination and persisted for at l ... | 1998 | 9785515 |
| future international management of african horse sickness vaccines. | three types of african horse sickness (ahs) vaccine, namely adult mouse brain, modified live vaccine and inactivated viral vaccine (ivv) are reviewed. the results of efficacy trials carried out with each vaccine type highlight the advantages of the ivv. vaccination with african horse sickness virus serotype 4 ivv, given as 2 separate doses, provided full protection against subsequent, homologous challenge. the absence of any detectable viraemia after challenge would also prevent infection of ins ... | 1998 | 9785514 |
| phylogenetic analysis of african horse sickness virus segment 10: sequence variation, virulence characteristics and cell exit. | african horse sickness virus (ahsv) genome segment 10 encodes the non-structural proteins ns3/ns3a, which is involved in release of virus from cells. full length segment 10 cdnas were amplified by reverse transcription-polymerase chain reaction, from isolates of ahsv serotypes 2, 3, 4, 5, 7, 8 and 9. these cdnas were cloned, sequenced and their phylogenetic relationships analysed. high levels of sequence homology were detected in segment 10 from some isolates of different serotypes, confirming t ... | 1998 | 9785513 |
| development of a mouse model system, coding assignments and identification of the genome segments controlling virulence of african horse sickness virus serotypes 3 and 8. | attenuated (att) and wild type (wt) strains of the nine ahsv serotypes were evaluated for virulence in adult balb c mice. although most were avirulent in this system, isolates of ahsv 1att, 3wt, 3att, 4wt, 5att, 7att and 8att caused some mortality when administered via an intranasal route. after plaque cloning, only the attenuated vaccine strain of ahsv 7att caused any mortality via an intravenous route. ahsv 3att and ahsv 8wt were virulent (v) and avirulent (av) (respectively) in the mouse mode ... | 1998 | 9785512 |
| characterization of two african horse sickness virus nonstructural proteins, ns1 and ns3. | each of the ten segments of the african horse sickness virus (ahsv) genome encodes at least one viral polypeptide. this report focuses on the nonstructural proteins ns1 and ns3, which are encoded by genome segments 5 and 10 respectively. the ns1 protein assembles into tubular structures, which are characteristically produced during orbivirus replication in infected cells. ns1 expressed by a recombinant baculovirus in sf9 cells also forms tubules, which were analysed electron microscopically. the ... | 1998 | 9785511 |
| structural studies of orbivirus particles. | we are using crystallographic methods to investigate the structure of ahsv and btv. our initial approach was to investigate the structure of the major protein component of the viral core, vp7(t13). this trimeric protein has been studied in several crystal forms from both orbiviruses and reveals a structure made up of conserved domains, capable of conformational changes and possessing a cleavage site. further crystallographic analyses of native particles have provided a picture of the vp7(t13) an ... | 1998 | 9785510 |
| molecular epidemiology of african horse sickness virus based on analyses and comparisons of genome segments 7 and 10. | this paper describes a method to rapidly identify african horse sickness virus (ahsv), using a single tube reverse transcription polymerase chain reaction (pcr). this method was used to amplify cdna copies of genome segments 7 and 10 from several different ahsv strains, of different serotypes, which were then analysed by sequencing and/or endonuclease digestion. ahsv vp7 (encoded by genome segment 7) is one of the two major capsid proteins of the inner capsid layer, forming the outer surface of ... | 1998 | 9785509 |
| vp7 from african horse sickness virus serotype 9 protects mice against a lethal, heterologous serotype challenge. | an established mouse model system was used to evaluate the effectiveness of the major outer core protein vp7 of african horse sickness virus (ahsv) serotype 9 as a subunit vaccine. balb c mice were immunised with vp7 crystals purified from ahsv infected bhk cells. in groups of mice, each of which was immunised with > or = 1.5 micrograms of the protein in freund's adjuvant, > or = 80% of mice survived challenge with a virulent strain of a heterologous ahsv serotype (ahsv 7), that killed > or = 80 ... | 1998 | 9785508 |
| expression of the major core structural proteins vp3 and vp7 of african horse sickness virus, and production of core-like particles. | the genome segments encoding the seven structural proteins of african horse sickness virus (ahsv), including the largest coding for vp1, were cloned and sequenced. analysis of the vp1 sequence supports the putative identity of this protein as an rna polymerase. the genes encoding the two major core proteins, vp3 and vp7, were also cloned and expressed by both in vitro translation and by means of recombinant baculoviruses. co-infection of insect cells with vp3 and vp7 recombinant baculoviruses re ... | 1998 | 9785507 |
| new generation of african horse sickness virus vaccines based on structural and molecular studies of the virus particles. | african horse sickness virus (ahsv) is a member of the genus orbivirus, which also includes bluetongue virus (btv) and epizootic haemorrhagic disease (ehdv) virus. these orbiviruses have similar morphological and biochemical properties, with distinctive pathobiological properties and host ranges. sequencing studies of the capsid proteins have revealed evolutionary relationships between these viruses. biochemical studies of the viruses together with the expression of individual proteins and prote ... | 1998 | 9785506 |
| duration of repellency of various synthetic and plant-derived preparations for culicoides imicola, the vector of african horse sickness virus. | objectives of the study were threefold: to find a safer and longer lasting repellent of the biting midge culicoides imicola than di-ethyl toluamide (deet), to examine whether the current recommendations in israel for application of repellents during an outbreak of c. imicola-borne pathogens are justified; and to examine whether plant-derived preparations that have no known detrimental side effects are potential replacements of synthetic repellents. of the seven repellents tested, those inferior ... | 1998 | 9785505 |
| effect of temperature on african horse sickness virus infection in culicoides. | this paper shows that both the infection rate and the rate of virogenesis of african horse sickness virus (ahsv) within vector culicoides are temperature dependent. as temperature is reduced from permissive levels the lifespan of the vector itself is extended but the rate of virogenesis decreases and infection rate falls dramatically so that at 10 degrees c virtually all midges are free from virus by 13 days post infection (dpi). when vectors that had been kept at this temperature for 35 days we ... | 1998 | 9785504 |
| studies of the mortality rate of culicoides imicola in morocco. | daily mortality rates of female culicoides imicola were found for eight sites in morocco in 1994 and for six sites in 1995. the mortality rates were found by operating pirbright-type light traps for a number of consecutive nights in late summer or autumn and finding the parous rate assuming a feeding interval of 3 to 5 days. the mortality rates were calculated according to established methods. in morocco the daily mortality rates were found to vary from about 5% per day (arbaoua, 1994, 1995 and ... | 1998 | 9785502 |
| the culicoides vectors of african horse sickness virus in morocco: distribution and epidemiological implications. | african horse sickness (ahs) is a vector-borne, infectious disease of equids caused by african horse sickness virus. the only proven field vector of the virus is the biting midge culicoides imicola, although c. obsoletus and c. pulicaris are suspected vectors. in 1994-5 a total of 3887 light trap samples were collected from 22 sites distributed over most of morocco. culicoides imicola was found to be very widely distributed with the greatest catches in the low-lying north-western areas (between ... | 1998 | 9785501 |
| immunohistochemical demonstration of african horse sickness viral antigen in tissues of experimentally infected equines. | african horse sickness virus (ahsv) antigen was demonstrated immunohistochemically in formalin-fixed, paraffin-embedded sections of tissues collected from three ponies suffering from the peracute form of the disease and from one pony affected by the fever form. the pattern of the antigen distribution indicated a particular organ tropism characterised by an accumulation of ahsv antigen in cardio-pulmonary tissues of the animals with the peracute disease and in the spleen of the pony with the feve ... | 1998 | 9785496 |
| clinical, virological and immune responses of normal and immunosuppressed donkeys (equus asinus africanus) after inoculation with african horse sickness virus. | to elucidate the role that donkeys may play in african horse sickness virus (ahsv) persistence during inter-epizootic periods we looked for clinical signs of infection and studied the viraemia and neutralising antibody kinetics in 3 immunocompetent and 3 immunosuppressed donkeys inoculated with ahsv-4. none of the donkeys developed signs of ahs. however infectious ahsv was isolated from the blood of the immunocompetent donkeys for up to 17 days post infection (dpi) and viral antigens were detect ... | 1998 | 9785495 |
| donkeys as reservoirs of african horse sickness virus. | investigations have been carried out to elucidate the possible role of the donkey in the epidemiology of african horse sickness (ahs). these studies have shown that despite the absence of pyrexia or other observable clinical signs, donkeys become infected with virulent ahs virus serotype 4 (ahsv 4) and that they develop a viraemia which can persist for at least 12 days, albeit at a comparatively lower titre than that recorded for similarly infected ponies. ahsv 4 showed a similar tissue tropism ... | 1998 | 9785494 |
| serological and virological responses in mules and donkeys following inoculation with african horse sickness virus serotype 4. | two groups, comprising 4 donkeys and 4 mules (group 1) and 4 donkeys and 3 mules (group 2), were used to determine the duration of viraemia and to monitor the development of antibodies following inoculation with african horse sickness virus (ahsv). one group of animals was given a single dose of attenuated ahsv serotype 4 (ahsv 4) vaccine. the second group was inoculated with a virulent field strain of ahsv 4. both groups were subsequently challenged with the virulent field strain of ahsv 4, 51 ... | 1998 | 9785493 |
| transmission and distribution of african horse sickness virus serotypes in south african zebra. | the prevalences of african horse sickness (ahs) virus serotypes in zebra foals from the kruger national park, south africa were examined for possible associations between serotypes. serotypes known to cross-react were combined for analysis. the distributions of serotypes between zebra were not always independent; in 7-8 month old zebra positive pairwise associations were observed between 3 serotypes. this could be generated by biological interactions between serotypes or heterogeneity in host-ve ... | 1998 | 9785492 |
| epidemiology of african horse sickness and the role of the zebra in south africa. | zebra are the only equine species native to south africa. these animals roamed over much of the country in the 17th century when horses and donkeys were first imported. the first cases of african horse sickness (ahs) then occurred in the horses of hunters who entered zebra territory. ahs continued to occur on a country-wide basis until the beginning of the 20th century, though the number of outbreaks decreased as the populations of zebra collapsed through overhunting. for most of the 20th centur ... | 1998 | 9785491 |
| taxonomy of african horse sickness viruses. | nine distinct genera are currently recognised within the virus family reoviridae, which include a total of 63 virus groups or species (species = virus group = electropherotype or serogroup), comprising 214 virus serotypes or subtypes, as well as 20 provisional types or subtypes, most of which (149 + 9 tentative) are assigned to the genus orbivirus [5, 9, 16]. the 19 species of orbiviruses (serogroups), were established principally on antigenic (serologic) grounds but many of these placements hav ... | 1998 | 9785490 |
| use of climatic data and satellite imagery to model the abundance of culicoides imicola, the vector of african horse sickness virus, in morocco. | african horse sickness (ahs) is a vector-borne, infectious disease of equids caused by african horse sickness virus (ahsv). the only proven field vector of the virus is the biting midge culicoides imicola. following a recent epizootic (1989-91) of ahs in morocco, light traps and automatic weather stations were operated for 2 years at twenty-two sites distributed over much of the country. the annually-averaged mean daily trap catch of c. imicola at these sites was negatively correlated with wind ... | 1998 | 9737597 |
| sequence-independent amplification and cloning of large dsrna virus genome segments by poly(da)-oligonucleotide ligation. | a strategy was developed for sequence-independent synthesis and amplification of full-length cdna of 3-4 kb genes of dsrna viruses. the method of single primer amplification (lambden et al., 1992) was adapted by the inclusion of a 3' poly(a) tail to an oligonucleotide ligated to dsrna genome segments as a template for oligo(dt)-primed cdna synthesis. full-length copies of the largest genome segments, 1 (4 kb) and 2 (3 kb), of african horse sickness virus (ahsv) have been cloned, terminally seque ... | 1998 | 9694332 |
| detection of african horsesickness virus and discrimination between two equine orbivirus serogroups by reverse transcription polymerase chain reaction. | a reverse transcription polymerase chain reaction (rt-pcr), based on the gene encoding the ns2 protein of african horsesickness virus (ahsv), was developed for rapid serogroup-specific detection of ahsv. the specificity of rt-pcr products was confirmed by southern blot hybridization using a radioactively labelled cdna probe specific for the ns2 gene. this rt-pcr could discriminate between all known members of the ahsv and equine encephalosis virus serogroups. ahsv rna was detected in a sample re ... | 1998 | 9629584 |
| culicoides in relation to transmission of african horse sickness virus in the gambia. | twelve light trap collections made near overnight shelters of horses and donkeys in four villages in the central river division of the gambia captured fourteen species of biting midge of the genus culicoides. five species new to the gambia were identified. this brought the number of recognized species of culicoides (after a revision of c. schultzei) to twenty-nine in the gambia. species known or suspected as vectors of african horse sickness virus (ahsv) and bluetongue virus (btv) comprised 83% ... | 1998 | 9622369 |
| the complete sequence of four major structural proteins of african horse sickness virus serotype 6: evolutionary relationships within and between the orbiviruses. | the amino acid sequences of four major capsid proteins of african horse sickness virus (serotype 6, ahsv-6) have been determined from analyses of cdna clones representing the l2, l3, m6 and s7 rna segments. the ahsv-6 l3 rna segment has an open reading frame of 2715 base pairs and encodes the inner capsid protein vp3 which comprises 905 amino acids. the vp3 layer forms the subcore of the virion and is surrounded by the vp7 protein which is encoded by the s7 gene. the ahsv-6 s7 gene was found to ... | 1998 | 9617769 |
| sequence analysis of the rna polymerase gene of african horse sickness virus. | the gene encoding the inner core protein vp1 of african horse sickness virus (ahsv) serotype 9 has been cloned, expressed in vitro and entirely sequenced, completing molecular characterization of the ahsv genome. an analysis of the sequence supporting the identity of ahsv vp1 as the putative viral rna polymerase is presented. | 1998 | 9541625 |
| intracellular production of african horsesickness virus core-like particles by expression of the two major core proteins, vp3 and vp7, in insect cells. | to gain more insight into the structure of the african horsesickness virus (ahsv) core particle, we have cloned, partially characterized and expressed the two major core proteins, vp3 and vp7, of ahsv-9. vp7 was found to be highly conserved amongst different serotypes. the vp3 and vp7 genes were subsequently expressed in insect cells by means of recombinant baculoviruses. vp7 was synthesized to very high levels and aggregated into distinctive crystals. co-expression of vp3 and vp7 resulted in th ... | 1998 | 9472617 |
| immunohistochemical demonstration of african horse sickness viral antigen in formalin-fixed equine tissues. | the distribution of viral antigen was studied in various tissues of three ponies, aged 3-4 years, infected experimentally with a virulent strain of african horse sickness virus (ahsv) serotype 4. tissues were collected from the animals in the terminal stage of the peracute form of the disease and from one noninfected horse, included as a control. a polyclonal antibody with specificity for ahsv, plus the nonstructural protein ns2, was used in a sensitive avidin-biotin-peroxidase-complex (abc) met ... | 1997 | 9396137 |
| effects of domain-switching and site-directed mutagenesis on the properties and functions of the vp7 proteins of two orbiviruses. | based on the crystal structure of the vp7 major core protein of bluetongue virus serotype 10 (btv-10) and that of the top domain of the vp7 protein of african horsesickness virus serotype 4 (ahsv-4), chimeras and site-directed mutants of the proteins were constructed and the products analyzed with respect to their properties and functions. chimeras with the central upper domain of btv-10 vp7 replaced by that of ahsv-4 vp7 (construct bab) formed trimers, as did the converse construct (aba). furth ... | 1997 | 9356334 |
| the spatial and seasonal distribution of african horse sickness and its potential culicoides vectors in morocco. | african horse sickness (ahs) is a vector-borne, infectious disease of equines that is caused by african horse sickness virus (ahsv). the only proven field vector is the biting midge culicoides imicola, although c. obsoletus and c. pulicaris are suspected vectors. there was a recent epizootic of ahs in iberia (1987-90) and morocco (1989-91). in 1994-45 a total of 3887 light trap samples were taken from twenty-two sites distributed over most of morocco. culicoides imicola was found to be very wide ... | 1997 | 9330250 |
| detection of african horse sickness virus in the blood of experimentally infected horses: comparison of virus isolation and a pcr assay. | a reverse transcription-polymerase chain reaction (rt-pcr) assay followed by dot-blot hybridisation was used to detect african horse sickness virus (ahsv); the primers employed amplified the s7 gene that encodes the vp7 protein. the rt-pcr assay was compared with virus isolation for detecting ahsv in blood samples form horses experimentally infected with ahsv-4 and ahsv-9. the influence of sample storage and transportation and the effects of two anticoagulants (edta and heparin) were also studie ... | 1997 | 9300539 |
| african horsesickness virus vp7 sub-unit vaccine protects mice against a lethal, heterologous serotype challenge. | an established mouse model was used to evaluate the effectiveness of the major outer core protein of african horsesickness virus (ahsv), vp7, as a subunit vaccine. adult female balb/c mice were immunized with vp7 crystals purified from bhk cells infected with ahsv serotype 9 (ahsv-9), using three inoculations in freund's adjuvant. eighty to one hundred per cent of the immunized mice were protected against a heterologous challenge with a known lethal dose of ahsv-7. the protected immunized mice d ... | 1997 | 9225037 |
| nucleotide sequence comparison of the segments s10 of the nine african horsesickness virus serotypes. | segments 10 (s10) of the double-stranded rna (ds rna) genomes from african horsesickness virus (ahsv) serotypes 2, 4, 5, 6 and 7 were cloned and sequenced. direct sequencing of previously reverse transcribed amplified (rt)-pcr segments s10 was also performed. nucleotide sequences of two strains (the virulent moroccan strain and a vaccine strain) of the same serotype (4) were determined. sequences of the viral serotypes were analysed and compared to each other. two in-phase atg codons were conser ... | 1997 | 9191861 |
| characterization of tubular structures composed of nonstructural protein ns1 of african horsesickness virus expressed in insect cells. | the characteristic tubules that are produced during the orbivirus infection cycle are composed of a major viral nonstructural protein, ns1. to characterize the ns1 gene and gene product of african horsesickness virus (ahsv), a full-length cdna copy of the ns1 gene of ahsv-6 was cloned and the nucleotide sequence determined. ns1 was highly conserved within the ahsv serogroup with between 95-98% conservation of amino acids among ns1 of ahsv-6, ahsv-4 and ahsv-9. the structure of ahsv ns1 tubules w ... | 1997 | 9152425 |
| spatial and seasonal distribution of culicoides imicola in iberia in relation to the transmission of african horse sickness virus. | collections of biting midges were made over 24 months from sixty sites spread across iberia. information on the distribution of the vector of african horse sickness virus, culicoides imicola, from these 3119 samples showed that this species was annually present across south-western spain as far as 3 degrees 53'w and throughout most of portugal, up to 41 degrees 5'n. c. imicola was found in all areas where african horse sickness epizootics had occurred in 1987-90 and also in areas outside the epi ... | 1997 | 9061677 |
| transmission and distribution of virus serotypes: african horse sickness in zebra. | the prevalence of african horse sickness (ahs) serotypes in zebra foals from the kruger national park, south africa was examined for possible associations between serotypes and to estimate the basic reproduction number, r0. the distributions of serotypes between zebra were not independent in the 6- and 7-8-month-old age classes (p < 0.005). this does not necessarily imply biological interactions between serotypes, as heterogeneity in host-vector transmission rates can generate non-independent di ... | 1997 | 9042034 |
| comparative sequence analysis and expression of the m6 gene, encoding the outer capsid protein vp5, of african horsesickness virus serotype nine. | the entire nucleotide and deduced amino acid sequence of the m6 gene of african horsesickness virus (ahsv) serotype nine has been determined from four overlapping cdna clones. the gene was found to be 1566 bp long, encoding a protein of 505 amino acids with a molecular weight of 56 737 da and a nett charge of - 1 at neutral ph comparative sequence analysis of the deduced amino acid sequence with the vp5 protein of ahsv-4, showed that only 81% of amino acids were conserved in type and position, a ... | 1997 | 9037735 |
| serologic markers in early stages of african horse sickness virus infection. | fifteen horses were experimentally infected with african horse sickness virus (ahsv) serotype 4. to learn more about the time course of production and specificity of ahsv-specific antibodies, sera were analyzed by immunoblot analysis. only animals that survived for more than 9 days were able to develop a humoral immune response detectable by immunoblotting. the earliest serological markers corresponded mainly to vp5, vp6, and ns2 and to a lesser extent to vp3, ns1, and ns3. neutralizing antibodi ... | 1997 | 9003637 |
| a novel cellular site-specific dna-binding protein cooperates with the viral ns1 polypeptide to initiate parvovirus dna replication. | replication of linear single-stranded parvovirus dna proceeds by a rolling-hairpin mechanism which generates long, palindromic, duplex concatamers. processing to monomer length requires initiation from origins of dna replication located at the 3' and 5' ends of each embedded monomer, reactions which can be recapitulated in vitro for minute virus of mice (mvm). to determine which cellular proteins were essential for replication from these origins, s100 extracts from 293s cells were fractionated o ... | 1997 | 8995666 |
| characterisation of wongorr virus, an australian orbivirus. | sequence analyses of vp3 gene segments of wongorr virus isolates from the northern territory of australia were compared with the cognate gene segments from picola and paroo river viruses. previous serological investigations had demonstrated some relationships between these viruses, however vp3 gene sequence and phylogenetic analyses placed these viruses within the same serogroup which was distinct from other described orbivirus serogroups. a polymerase chain reaction (pcr) was developed for the ... | 1996 | 8879140 |
| subcellular localization of the nonstructural protein ns3 of african horsesickness virus. | the subcellular localization of the minor nonstructural protein ns3 of african horsesickness virus (ahsv) has been investigated by means of immunogold electron-microscopical analysis. ns3 was observed in perturbed regions of the plasma membrane of ahsv-infected vero cells, and its presence appears to be associated with events of viral release. these events are budding, whereby released viruses acquire fragments from the host-cell membrane, as well as by the extrusion of nonenveloped particles th ... | 1996 | 8848304 |
| role of dogs (canis domesticus) as hosts for african horse sickness virus. | at bet dagan culicoides imicola kieffer, c. schultzei gp. (a mammal feeder), culex pipiens l. (a laboratory vector) and culex univittatus theobald were found in significantly (p < 0.05) smaller numbers near dogs than near other hosts, while phlebotomus spp. were found in significantly (p < 0.05) higher numbers in dog kennels than in other animal houses. some 400 blood meals of culicoides spp. from israel and zimbabwe were negative for canine blood. only 1 of 16 blood meals of culex pipiens caugh ... | 1996 | 8828119 |
| recombinant baculovirus-synthesized african horsesickness virus (ahsv) outer-capsid protein vp2 provides protection against virulent ahsv challenge. | african horsesickness virus serotype 4 (ahsv-4) outer-capsid proteins vp2 or vp2 and vp5, prepared from single or dual recombinant baculovirus expression vectors grown in sf9 insect cells, were administered in different amounts to horses and the neutralizing antibody responses were measured. control and vaccinated horses were challenged with virulent ahsv-4 6 months later and monitored post challenge. the results indicated that two inoculations of extracts containing vp2 and vp5, or vp2 alone, i ... | 1996 | 8811002 |
| a blocking elisa for detection of antibody to a subgroup-reactive epitope of african horsesickness viral protein 7 (vp7) using a novel gamma-irradiated antigen. | a novel gamma irradiated inactivated cell culture derived african horsesickness viral (ahsv) antigen was used in a blocking elisa (b-elisa) for detecting antibody to a subgroup-reactive epitope of ahsv. a monoclonal antibody (mab), class igm, against an epitope on african horsesickness (ahs) viral protein 7 (vp7) was developed in balbc mice and used in the b-elisa. the mab, designated f9h, was blocked by 69 serums from equidae with antibody to ahs, but its binding activity was not appreciably af ... | 1996 | 8784514 |
| workshop on the geographic spread of aedes albopictus in europe and the concern among public health authorities. proceedings of a workshop held at the istituto superiore di sanità, rome, italy, 19-20 december 1994. | 1995 | 8778669 | |
| characterization of the gene encoding core protein vp6 of two african horsesickness virus serotypes. | the genes encoding the inner core protein vp6 of african horsesickness virus (ahsv) serotypes 3 and 6 have been cloned and sequenced. the genes are 1169 nucleotides in length and both encode a largely hydrophilic protein of 369 amino acids. the vp6 amino acid sequence is highly conserved between the two serotypes with an overall similarity of 95 percent. comparison of the ahsv vp6 amino acid sequences with those of bluetongue virus serotype 10 vp6 revealed that it is 41 amino acids longer with a ... | 1996 | 8757982 |
| differentiation of african horse sickness viruses by polymerase chain reaction and segments 10 restriction patterns. | this paper describes a single tube reverse transcription-polymerase chain reaction (rt-pcr) method for detection of african horse sickness virus (ahsv). the genomic segments 10 of viruses of the 9 ahsv serotypes were amplified. the 758bp products were digested to completion by restriction enzymes. the restriction fragment length polymorphisms of segments 7 and 10 cdna allowed the differentiation of the nine serotypes. | 1995 | 8748551 |
| detection and differentiation of epizootic haemorrhagic disease of deer and bluetongue viruses by serogroup-specific sandwich elisa. | a serogroup specific sandwich elisa was developed for the detection of epizootic haemorrhagic disease of deer viruses (ehdv) in infected insects and tissue culture preparations. polyclonal rabbit antiserum against purified ehdv core particles was used to capture viral antigen and specific binding detected using guinea pig antisera against ehdv core particles followed by anti-guinea pig immunoglobulin enzyme-labelled conjugate. the assay is ehdv specific and detects all 8 serotypes. no cross-reac ... | 1996 | 8690767 |
| full protection against african horsesickness (ahs) in horses induced by baculovirus-derived ahs virus serotype 4 vp2, vp5 and vp7. | african horsesickness virus serotype 4 (ahsv-4) outer capsid protein vp2, or vp2 and vp5 plus inner capsid protein vp7, derived from single or dual recombinant baculovirus expression vectors were used in different combinations to immunize horses. when the proteins were purified by affinity chromatography, the combination of all three proteins induced low levels of neutralizing antibodies and conferred protection against virulent virus challenge. however, purified vp2 or vp2 and vp5 in the absenc ... | 1996 | 8683209 |
| epidemiology of african horsesickness: antibodies in free-living elephants (loxodonta africans) and their response to experimental infection. | the presence of low levels of group- and type-specific antibodies against african horsesickness virus in the serum of some free-living elephants was reconfirmed. experimental infection resulted in conflicting results. no detectable viraemia nor virus could be demonstrated in the organs of the six elephant calves and none of them mounted significant levels of neutralizing antibodies against the virus. on the other hand, all calves showed a slight rise in elisa titres. this rise, however, was mode ... | 1995 | 8668325 |
| detection of bluetongue virus and african horsesickness virus in co-infected cell cultures with ns1 gene probes. | the serogroup specificity of the bluetongue virus (btv) ns1 and vp3 gene probes was confirmed by means of northern blot hybridization. under high-stringency conditions both probes hybridized to 22 btv serotypes (18 south african serotypes, btv3 from cyprus and btv16 from pakistan) but not to serotypes that originate from australia and india. furthermore, ns1 gene probes of btv and african horsesickness virus (ahsv) were used in a dot-spot in situ hybridization procedure to differentiate between ... | 1995 | 8668318 |
| a potential proline-rich motif upstream of the immunoreceptor tyrosine-based activation motif in bovine leukemia virus gp30, epstein-barr virus lmp2a, herpesvirus papio lmp2a, and african horsesickness virus vp7. | 1996 | 8661376 | |
| immunization with vp2 is sufficient for protection against lethal challenge with african horsesickness virus type 4. | horses were immunized by inoculation with a vaccinia construct containing a full-length cdna corresponding to the l2 gene segment of african horsesickness virus type 4(ahsv-4). all immunized horses developed serum neutralizing antibodies prior to challenge with virulent ahsv-4. no elisa-reactive antibodies were present prior to challenge. a group of four seronegative control horses died after developing clinical signs and lesions typical of the pulmonary form of african horsesickness while the i ... | 1996 | 8659117 |
| crystal structure of the top domain of african horse sickness virus vp7: comparisons with bluetongue virus vp7. | the baculovirus-expressed core protein vp7 of african horse sickness virus serotype 4 (ahsv-4) has been purified to homogeneity and crystallized in the presence of 2.8 m urea. the x-ray structure has been solved to a 2.3-angstroms (1 angstrom = 0.1 nm) resolution with an rfactor of 19.8%. the structure of ahsv vp7 reveals that during crystallization, the two-domain protein is cleaved and only the top domain remains. a similar problem was encountered previously with bluetongue virus (btv) vp7 (wh ... | 1996 | 8648715 |
| african horse sickness and african carnivores. | african horse sickness (ahs) is a disease that affects equids, and is principally transmitted by culicoides spp. that are biological vectors of ahs viruses (ahsv). the repeated spread of ahsv from sub-saharan africa to the middle east, northern africa and the iberian peninsula indicate that a better understanding of ahs epizootiology is needed. african horse sickness has long been known to infect and cause mortality among domestic dogs that ingest virus contaminated meat, but it is uncertain wha ... | 1995 | 8604545 |
| african horse sickness surveillance systems and regionalisation/zoning: the case of south africa. | central and southern africa are generally regarded as being endemic areas for african horse sickness (ahs). with the advent of the concepts of risk analysis and regionalisation/zoning, however, the possibility has now arisen of establishing 'zones' within south africa for ahs surveillance purposes. in 1993, a protocol was submitted to the european community (now european union: eu), proposing the establishment of an ahs-free zone in the cape peninsula. the proposal is based on historical evidenc ... | 1995 | 8593398 |
| the use of african horse sickness virus ns3 protein, expressed in bacteria, as a marker to differentiate infected from vaccinated horses. | segment 10 of the double-stranded rna (dsrna) genome from african horse sickness virus serotype 4 (ahsv-4) was cloned and sequenced. the sequence of the coding region showed a total length of 667 bp. nucleotide comparisons showed a 95% sequence similarity between serotypes 4 and 9, and 76% between serotypes 4 and 3. cdna clones containing the coding region were cloned in the vector pet3xb and expressed in escherichia coli. the ns3 gene product was synthesised at very high level as an insoluble f ... | 1995 | 8578859 |
| an amino-terminal polypeptide fragment of the influenza virus ns1 protein possesses specific rna-binding activity and largely helical backbone structure. | the ns1 protein of influenza a virus has the unique property of binding to three apparently different rnas: poly a; a stem-bulge in u6 small nuclear rna; and double-stranded rna. one of our major goals is to determine how the ns1 protein recognizes and binds to its several rna targets. as the first step for conducting structural studies, we have succeeded in identifying a fragment of the ns1 protein that possesses all the rna-binding activities of the full-length protein. the rna-binding fragmen ... | 1995 | 8548659 |
| rapid generation of monoclonal antibody-secreting hybridomas against african horse sickness virus by in vitro immunization and the fusion/cloning technique. | splenocytes from non-immune mice were stimulated in vitro using an equimolar mixture of factors from mixed lymphocyte reaction (mlr) and from phorbol-12-myristate 13-acetate (pma) stimulated el-4 cells, and concomitantly immunized with inactivated african horse sickness virus (ahsv) antigen serotype 4 or viral proteins 2 and 5 from ahsv serotype 9. fusion with nso myeloma cells was performed five days after primary or secondary stimulation/immunization. the record of hybridoma growth after a sta ... | 1993 | 8505546 |
| african horse sickness viruses isolated in kenya. | 1993 | 8498004 | |
| characterization of african horsesickness virus serotype 4-induced polypeptides in vero cells and their reactivity in western immunoblotting. | the structural and non-structural proteins induced by african horsesickness virus serotype 4 (ahsv-4) in infected vero cells were analysed by sds-page. twenty-two virus-induced polypeptides were detected in infected cells by comparison with the polypeptides of mock-infected cells, of which four major (vp2, vp3, vp5 and vp7) and three minor (vp1, vp4 and vp6) structural proteins and four non-structural proteins (p58, p48, p21 and p20) were shown to be virus-coded, as deduced from electrophoretic ... | 1993 | 8423451 |
| separation of small infective components of mef1 poliomyelitis and horsesickness viruses by migration into agar gels. 1955. | 1993 | 8396246 | |
| a rapid method for the purification of the mef1 strain of poliomyelitis virus. 1954. | 1993 | 8396245 | |
| use of a digoxigenin-labeled rna probe to detect all 24 serotypes of bluetongue virus in cell culture. | a digoxigenin-labeled rna probe, corresponding to the section of the bluetongue virus (btv) serotype 17 genome coding for nonstructural protein-1 (ns1), was applied to noninfected cell cultures and cell cultures infected with 24 different serotypes of btv, 2 serotypes of epizootic hemorrhagic disease virus, and african horse sickness virus type 4. the probe hybridized to all cell cultures infected with the various btv serotypes but did not hybridize to noninfected cell cultures or cell cultures ... | 1993 | 8389596 |
| group-reactive elisas for detecting antibodies to african horsesickness and equine encephalosis viruses in horse, donkey, and zebra sera. | group-reactive enzyme-linked immunosorbent assays (elisas) were developed to selectively detect antibodies to african horsesickness virus (ahsv) and equine encephalosis virus (eev), 2 orbiviruses that infect equids. in indirect elisa, guinea pig antisera to all known ahsv or eev serotypes recognized immobilized ahsv serotype 3 or eev cascara, respectively. antisera from naturally infected animals did not cross-react with their respective heterologous viruses. the elisa was used in parallel with ... | 1993 | 8385502 |
| seroepidemiological study of african horse sickness virus in the gambia. | an indirect enzyme-linked immunosorbent assay was used for the screening of horse sera from the gambia for antibodies against african horse sickness virus (ahsv). the ahsv antigen used for coating was semipurified according to the method of manning and chen (curr. microbiol. 4:381, 1980); control mock-infected vero cell antigen was treated in the same manner. a total of 459 horse serum samples were assayed at a single dilution (1:10), and their reactivities were compared with those of reference ... | 1993 | 8370760 |
| purification of viruses by electrophoresis in sucrose concentration gradients. 1972. | zone electrophoresis (ze) in concentration gradients of sucrose proved to be a powerful technique in the purification of viruses although it is seldomly used as a single step for the separation of the infective agent from extraneous matter but usually as a final procedure. no difficulties were experienced in the purification of plant viruses with ze possibly because of the resistance of the agents to the chloroform butanol treatment which the impure plant viruses received prior to the ze. likewi ... | 1993 | 8367394 |
| african horse sickness. | ahs is a noncontagious vector-borne disease of equidae caused by orbiviruses. species susceptibility in decreasing order is horses, mules, donkeys, and zebras. the main vectors of ahs are culicoides. the disease is endemic in sub-saharan africa, but epizootics have occurred outside of this area on several occasions. the most recent outbreaks outside of the endemic area were in spain, morocco, and portugal between 1987 and 1990. ahs causes mortality up to 95% and is classically divided into four ... | 1993 | 8358648 |
| the complete nucleotide sequence of african horsesickness virus serotype 4 (vaccine strain) segment 4, which encodes the minor core protein vp4. | the complete sequence of rna segment 4 of african horsesickness virus serotype 4 (ahsv-4) vaccine strain was determined from the full-length cdna clone inserted into pbr322. the rna is 1978 bp long (m(r) 1.27 x 10(6)) and contains an open reading frame encoding a protein of 642 amino acids (m(r) 75826) with a net charge of +10 at neutral ph. the 5' and 3' termini of ahsv-4 segment 4,5'gtttat... and ...ccttac3', were different from orbivirus characteristic terminal sequences, being 5'gttaaa... an ... | 1993 | 8346671 |
| current status of the diagnosis and control of african horse sickness. | african horse sickness (ahs) is an infectious, non-contagious, highly fatal viral disease of equidae, transmitted by arthropod vectors of the genus culicoides, and endemic in africa south and east of the sahara. the disease is caused by a virus of the reoviridae family, genus orbivirus, and 9 serotypes have been recognized. recent outbreaks of ahs in the iberian peninsula and northern africa emphasize the need for accurate diagnosis and rapid implementation of control measures. in this paper, th ... | 1993 | 8343805 |
| characterization of virulence variants of african horsesickness virus. | there are three clinicopathologic syndromes associated with african horsesickness (ahs) virus infection in horses. these different forms of ahs (pulmonary, cardiac, and fever forms) vary in the organs affected, the severity of lesions, time of onset of clinical signs and mortality rates. we have studied the effects of infection with three cell culture passaged variants of ahs virus in naive north american horses. one of these viruses, ahs/4sp, consistently caused the pulmonary form of ahs with r ... | 1993 | 8337849 |
| circulation of african horsesickness virus in zebra (equus burchelli) in the kruger national park, south africa, as measured by the prevalence of type specific antibodies. | in the kruger national park 75% of zebra foals are born in october-march and they lose their passive immunity against african horsesickness virus (ahsv) when they are 5-6 months old. one month later infection with different serotypes of ahsv amounts to 31% and thereafter infections increase rapidly to almost 100% before the foals are 12 months old. the capability of zebra to maintain ahsv is clearly illustrated by the continuing infections during every month of the year with a peak period in win ... | 1993 | 8332321 |
| diagnosis and molecular epidemiology of the african horse sickness virus by the polymerase chain reaction and restriction patterns. | african horse sickness is a viral disease caused by an orbivirus belonging to the reoviridae family. this paper describes a polymerase chain reaction (pcr) for amplifying segments 7, which encode for vp 7, a protein common to the 9 known serotypes of this virus. a reverse transcription step is necessary before amplification. no amplified product could be observed in cell cultures infected with other equine viruses. the amplified dnas were digested to completion by 8 different restriction enzymes ... | 1993 | 8260960 |
| isolation and identification of african horse sickness virus during an outbreak in lagos, nigeria. | an outbreak of african horse sickness involving two horse stables in lagos, nigeria, was investigated. inoculation of blood from infected horses into suckling albino mice resulted in isolation of a virus which was identified as african horse sickness virus by the complement fixation test. the clinical, pathological and epizootiological findings (reported elsewhere) were consistent with african horse sickness. potential threats of the epidemic to international horse trade are briefly highlighted. | 1993 | 8219337 |
| detection of african horse sickness virus by reverse transcription-pcr. | reverse transcription-pcr (rt-pcr) was used to detect african horse sickness virus (ahsv). a single primer pair which amplified a 423-bp fragment of the s8 gene which encodes the ns2 protein of ahsv was identified. amplification of this fragment from all nine serotypes of ahsv was achieved with these primers. between 10(1) and 10(2) copies of ahsv genomic double-stranded rna could be detected by rt-pcr followed by agarose gel electrophoresis and ethidium bromide staining. application of rt-pcr t ... | 1994 | 8195381 |
| development of a nested-pcr test based on sequence analysis of epizootic hemorrhagic disease viruses non-structural protein 1 (ns1). | two orbiviruses, epizootic hemorrhagic disease (ehd) and bluetongue (btv) viruses, cause disease in domestic and wild ruminant species. the gene that encodes non-structural protein 1 (ns1) of ehd virus, serotype 1, was sequenced and compared to ehd and btv ns1 sequences. the ns1 gene was found to be more conserved than the vp3 gene, and was selected as a target for polymerase chain reaction (pcr) amplification. the ns1 genes of several btv viruses and another orbivirus, african horse sickness (a ... | 1994 | 8191788 |
| diagnosis of the african horse sickness virus serotype 4 by a one-tube, one manipulation rt-pcr reaction from infected organs. | a single tube reverse transcription-polymerase chain reaction (rt-pcr) method for detection of african horse sickness virus (ahsv) in splenic tissues from infected horses is described. double stranded rna was extracted from infected organs of horses and used to produce complementary dna (cdna) with the two primers selected for the pcr. the 1179 bp amplified product (the segment 7 which encodes for vp 7), detected by electrophoresis on agarose gel and ethidium bromide staining, was hydrolysed wit ... | 1994 | 8188813 |
| identification of domains in bluetongue virus vp3 molecules essential for the assembly of virus cores. | bluetongue virus (btv) cores consist of the viral genome and five proteins, including two major components (vp3 and vp7) and three minor components (vp1, vp4, and vp6). vp3 proteins form an inner scaffold for the deposition on the core of the surface layer of vp7. vp3 also encapsidates and interacts with the three minor proteins. the btv vp3 protein consists of 901 amino acids and has a sequence that is a highly conserved among btv serotypes and other orbiviruses (e.g., epizootic hemorrhagic dis ... | 1994 | 8151751 |
| further studies on the efficacy of an inactivated african horse sickness serotype 4 vaccine. | the immunity induced by two inoculations of a commercial inactivated african horse sickness (ahs) serotype 4 (ahsv-4) vaccine was studied. no adverse reaction was observed in five horses following vaccination. following challenge-inoculation, no clinical signs attributable to ahs, no viraemia indicating infection, and no anamnestic response was observed in the vaccinated ponies. two control ponies developed clinical signs typical of ahs, high levels of viraemia, and died 7 and 8 days postchallen ... | 1994 | 8147096 |