| an analysis of co-circulating serotypes for bluetongue-17 virulence markers. | we have recently identified two markers associated with virulent strains of bluetongue virus serotype 17. these differences are an altered antigenic structure of the outer capsid protein vp2 and an increased electrophoretic mobility of the rna segment 3 that codes for an inner core protein. we did not observe these markers in confirmed avirulent strains of bluetongue virus serotype 17. we hypothesized that these virulence-associated markers may have been acquired by bluetongue-17 through genetic ... | 1995 | 7476098 |
| identification of the major north american bluetongue viruses using nucleic acid amplification techniques. | a set of primers (btv-pr1/2) were selected that hybridized to the vp3 gene of the major north american serotypes of bluetongue virus (btv). polymerase chain reaction (pcr) testing yielded positive results from specimens of major north american btv isolates (serotypes 10, 11, 13 and 17) propagated in vero cells. in addition, pcr assays were positive from samples of all other btv serotypes, except btv-16; however, an alternative primer pair (btv-prn1/n2) was devised for amplification of this serot ... | 1995 | 7477017 |
| the virtual absence of culicoides imicola (diptera: ceratopogonidae) in a light-trap survey of the colder, high-lying area of the eastern orange free state, south africa, and implications for the transmission of arboviruses. | altogether 52 078 culicoides biting midges of 35 species were collected during february 1990 and 1993 in 40 light-trap collections made on 17 cattle and/or sheep farms in the bethlehem and fouriesburg districts of the colder, high-lying eastern orange free state. culicoides (avaritia) bolitinos was by far the most abundant species, representing 50.9% of all specimens collected. culicoides (a.) imicola, considered to be the most common stock-associated species in the summer rainfall areas of sout ... | 1994 | 7501364 |
| fine mapping of a continuous epitope on vp7 of bluetongue virus using overlapping synthetic peptides and a random epitope library. | two complementary techniques have been used to delineate an epitope on vp7 of bluetongue virus. two mabs (f10 and d11), both of which bound within a region spanning amino acids 255 to 274 in the 349 amino acid protein, were used to probe overlapping synthetic peptides covering this region. a pentapeptide, qypal, and a hexapeptide, qy-palt (amino acids 259-264), preferentially bound both mabs. mab f10 also reacted with a heptapeptide (taeifnv) immediately adjacent to qypalt. the mabs were also us ... | 1994 | 7505073 |
| bluetongue virus: production and study of viral antigen for serological diagnosis. | a soluble antigen, produced from the culture supernatant of vero cells infected with bluetongue virus serotype 4 (btv-s4) and concentrated by sequential ultrafiltration with membranes with cut-off values 10(3) and 25 x 10(3) nmwp, showed complete identity to standard antigens when compared by agar gel immunodiffusion (agid) and sds-page profiles, revealing that the main protein component responsible for the agid reaction has a molecular weight of about 60 kda corresponding probably to the ns1 pr ... | 1993 | 7505285 |
| mapping and characterization of antigenic epitopes and the nucleic acid-binding domains of the vp6 protein of bluetongue viruses. | heterologously expressed vp6 and truncated vp6 proteins of bluetongue virus (btv) serotype 11 purified to near homogeneity were used for structure and function analyses. the yield of the expressed vp6 was host cell dependent. six antigenic epitopes of vp6 of btv were identified and mapped by immunoblot analyses and enzyme-linked immunosorbent assay with oligoclonal antibodies. these determinants were surface accessible and conserved among the cognate vp6 proteins of five u.s. btv serotypes. the ... | 1994 | 7514678 |
| expression of the non-structural protein ns1 of bluetongue virus in bacteria and yeast: identification of two antigenic sites at the amino terminus. | cdna transcribed from bluetongue virus serotype 1 (australia) dsrna 5 coding for non-structural protein ns1 was amplified in a polymerase chain reaction and ligated downstream of the t7 rna polymerase promoter in the bacterial expression plasmid pet-5b, as a fusion protein with glutathione s-transferase using the pgex bacterial expression system or the metallothionein promoter in the yeast expression plasmid pyelc5. the linear epitopes bound by six monoclonal antibodies to ns1 were localised to ... | 1994 | 7514825 |
| use of a gene-targeted phage display random epitope library to map an antigenic determinant on the bluetongue virus outer capsid protein vp5. | we describe the use of a gene-targeted random epitope library for the mapping of antigenic determinants. a dna clone encoding the target antigen was digested randomly with dnase i to generate a population of dna fragments of different sizes and sequences. after size fractionation, small dna fragments (100-200 bp) were isolated and cloned into the phage expression vector fuse2 to form an expression library displaying random polypeptide sequences as fusion proteins at the n terminus of the phage g ... | 1995 | 7530266 |
| characterization and modification of the carboxy-terminal sequences of bluetongue virus type 10 ns1 protein in relation to tubule formation and location of an antigenic epitope in the vicinity of the carboxy terminus of the protein. | bluetongue virus produces large numbers of tubules during infection. the tubules are formed from a 552-amino-acid, 64-kda ns1 protein encoded by the viral double-stranded rna segment m6. a series of deletion and extension mutants of bluetongue virus serotype 10 ns1 has been generated and expressed in insect cells in order to identify the carboxy-terminal components of the protein which are important for tubule formation. the mutants acct5 and acct10, lacking 5 and 10 of the carboxy-terminal resi ... | 1995 | 7535866 |
| homotypic and heterotypic neutralization determinants of bluetongue virus serotype 17. | homotypic and heterotypic neutralization determinants of bluetongue virus serotype 17 (btv-17) were investigated with a panel of five neutralizing monoclonal antibodies (mabs). one mab (mab 034) was originally raised to btv serotype 10 (btv-10) but also neutralizes btv-17 (p. v. rossitto, and n. j. maclachlan, 1992, j. gen. virol. 73, 1947-1952). competitive binding studies indicate that the mabs recognize at least two epitopes on the neutralizing outer capsid protein vp2 of btv-17. the mabs wer ... | 1995 | 7538255 |
| the multimeric nonstructural ns2 proteins of bluetongue virus, african horsesickness virus, and epizootic hemorrhagic disease virus differ in their single-stranded rna-binding ability. | the structure and single-stranded (ss) rna-binding by the nonstructural protein ns2 of three different orbiviruses were studied and compared. african horsesickness virus (ahsv), bluetongue virus (btv), and epizootic hemorrhagic disease virus (ehdv) were analyzed in recombinant baculovirus-infected cells and in cells infected with btv and ahsv. sedimentation analysis and nonreducing sds-page revealed that ns2 of all three orbiviruses is a 7s multimer with both inter- and intramolecular disulfide ... | 1995 | 7539971 |
| action of quail and chicken interferons on a quail cell line, qt35. | production of interferon (ifn) in quail cells (qt35) and the activity of quail ifn and heterologous avian ifn (chicken) on qt35 cells were examined. quail cells produced ifn after induction by bluetongue virus serotype 10; chicken and quail ifn conferred antiviral resistance on the quail cells. both chicken and quail ifn induced increased levels of 2',5'-oligoadenylate synthetase (2',5'-oas) in qt35 cells and reduced levels of intracellular salmonella typhimurium postchallenge. these results ind ... | 1995 | 7543005 |
| investigation of sheep-associated malignant catarrhal fever virus infection in ruminants by pcr and competitive inhibition enzyme-linked immunosorbent assay. | development of control measures for the gammaherpesviral disease of cattle known as sheep-associated malignant catarrhal fever (sa-mcf) has been hampered by a lack of accurate diagnostic tests either for the causative virus or for antibody against that virus. a recently developed competitive-inhibition enzyme-linked immunosorbent assay (ci-elisa) for the detection of antibody to malignant catarrhal fever (mcf) virus (mcfv) in ruminants based on a monoclonal antibody to a widely conserved epitope ... | 1995 | 7559946 |
| development of a two-site immuno-pcr assay for hepatitis b surface antigen. | hepatitis b virus (hbv) gene transcription may occur at very low levels resulting in hbsag concentrations in serum and liver below the limit of detection by currently available immunoassays. an assay has been developed that combines the specificity of two high affinity anti-hbs monoclonal antibodies (mab) directed against distinct and separate determinants in the 'a' domain of hbsag with the highly sensitive polymerase chain reaction (pcr) detection method. following capture of hbsag present in ... | 1995 | 7601903 |
| response of the regional lymph node to bluetongue virus infection in calves. | bluetongue virus (btv) infection of cattle is characterized by prolonged cell-associated viremia. in an effort to further evaluate the antiviral response of btv-infected cattle, the role of the regional lymph node (ln) in the immune response of calves to btv was characterized. calves were inoculated with btv in the skin of the neck in an area drained by the superficial cervical ln. calves were euthanized at regular intervals after inoculation and both btv-challenged and contralateral (control) s ... | 1995 | 7604539 |
| growth of a neuroinvasive strain of bluetongue virus in suckling mice. | some strains of bluetongue virus cause congenital brain damage in bovine and ovine fetuses, as well as in neonatal mice. two strains of bluetongue virus serotype 11 (uc-2 and uc-8) which differ in neuroinvasiveness were used to determine the biological basis for this difference. uc-2 and uc-8 were inoculated subcutaneously into newborn mice and virus was titrated from blood, plasma and brain tissues over 14 days. for the invasive uc-8 strain, 50-175 plaque forming units of virus per ml was found ... | 1995 | 7605202 |
| adaptation of bluetongue virus in mosquito cells results in overexpression of ns3 proteins and release of virus particles. | adaptation of bluetongue virus (btv) to grow in mosquito cells (c6/36) resulted in overexpression of two non-structural proteins (ns3 and ns3a) in infected cells. these proteins also co-purified with btv particles and were dissociated from the virions upon treatment with an anionic detergent. the expression was not host dependent, since back inoculation of the adapted virus into mammalian cell cultures also resulted in a significant overexpression of these proteins. the btv-c6/36 produced smalle ... | 1995 | 7605208 |
| prevalence of five serotypes of bluetongue virus in a rambouillet sheep flock in pakistan. | | 1995 | 7645187 |
| evaluation of an agar gel immunodiffusion test to detect infection of cattle with bluetongue viruses in queensland, australia. | an agar gel immunodiffusion (agid) test to detect group-specific antibodies to infection of cattle by bluetongue viruses was evaluated using field collected sera in queensland, australia. the agid test was compared to the serum neutralisation (sn) test used to detect serotype-specific bluetongue virus antibodies. the agid test was found to be highly sensitive (95% confidence interval, 80.7-100%) but to have moderate specificity (95% confidence interval, 59.3-79.6%), relative to the sn test. the ... | 1995 | 7653026 |
| infection of cattle with bluetongue viruses in queensland, australia: results of a sentinel herd study, 1990-1992. | between 1990 and 1992, 47 sentinel herds of 10-20 cattle each were established throughout queensland, australia to monitor bluetongue virus infection. sixteen herds at 12 locations seroconverted to bluetongue viruses during the study. herd incidence rates ranged from 0.0 to 3.45 seroconversions per cattle-year at risk. the mean incidence rate was 0.29 seroconversions per cattle-year at risk (95% confidence interval 0.23-0.36), and the median incidence rate was 0.32 seroconversions per cattle-yea ... | 1995 | 7653027 |
| comparison of the non-structural protein, ns1, of tick-borne and insect-borne orbiviruses. | the nucleotide sequence of rna segment 6 of broadhaven virus (brdv), a tick-borne orbivirus, was determined principally from two overlapping cdna clones and rna end sequence analysis. the genome segment is 1714 base pairs in length and has a coding capacity for a protein of 537 amino acids, having a net charge of +4.0 at neutral ph. comparison of the predicted amino acid sequence of brdv rna segment 6 with the ns1 sequence of insect-borne orbiviruses, bluetongue virus (btv), african horse sickne ... | 1995 | 7653106 |
| infection of cattle in queensland with bluetongue viruses: 1. prevalence of antibodies. | a survey of nearly 20,000 cattle in queensland was conducted to describe the prevalence and distribution of infection by serotypes of bluetongue virus. the overall prevalence of serum antibodies to one or more bluetongue viruses was 8.7% (95% confidence interval 8.3 to 9.1). sera from cattle contained neutralising activity against 2 serotypes, 1 and 21. no evidence was found of infection with other serotypes previously isolated in australia. the overall prevalence of serotype 1 antibodies was 7. ... | 1995 | 7661819 |
| bluetongue and douglas virus activity in new south wales in 1989: further evidence for long-distance dispersal of the biting midge culicoides brevitarsis. | | 1995 | 7661825 |
| glycosylation of the major outer capsid protein of bluetongue viruses. | the major outer capsid protein, vp5, of five us bluetongue viruses, was found to be glycosylated. enzymatic removal of the carbohydrate moiety did not affect the electrophoretic mobility of vp5 in sds-page, indicating the presence of only short and possibly unbranched oligosaccharide chains. the surface accessibilities and immunogenic specificities of two conformational-dependent antigenic epitopes on vp5 of btv were not affected by deglycosylation. selective binding of those lectins which have ... | 1993 | 7683160 |
| neutralization determinants of united states bluetongue virus serotype ten. | a panel of five neutralization-resistant escape mutant (em) viruses was used to investigate the neutralization determinants of the u.s. prototype strain of bluetongue virus serotype 10 (btv-10). the phenotypic properties of each em virus were characterized by neutralization and immuneprecipitation assays with a panel of four monoclonal antibodies (mabs). these mabs were used to select the various em viruses and together the mabs define four distinct neutralizing epitopes on the prototype strain ... | 1993 | 7686312 |
| identification and localization of a serotypic neutralization determinant on the vp2 protein of bluetongue virus 13. | we have used a serotype-specific monoclonal antibody to locate a neutralization epitope on the outer capsid protein, vp2, of the bluetongue virus 13. this surface-accessible region of the virion was recognized by a monoclonal antibody, d24.15, which exhibited serotype-specific neutralizing activity as determined by plaque reduction assay. in western blots, this monoclonal antibody reacted only with the vp2 of bluetongue virus 13, but not with any of the other us btv serotypes. competition with s ... | 1993 | 7687805 |
| effects of temperature on virogenesis of bluetongue virus serotype 11 in culicoides variipennis sonorensis. | culicoides variipennis sonorensis females were fed bluetongue virus serotype 11 mixed in sheep blood and were held at constant temperatures of 32, 27, 21 and 15 degrees c. virogenesis, as measured by enzyme-linked immunosorbent assay (elisa), proceeded significantly faster at higher temperatures. based on elisa absorbance > or = 0.2, some flies first were categorized as infected after 1 day, 2 days and 4 days at 32, 27 and 21 degrees c, respectively. peak levels of virus antigen were seen after ... | 1995 | 7696691 |
| expression of nonstructural protein ns3 of african horsesickness virus (ahsv): evidence for a cytotoxic effect of ns3 in insect cells, and characterization of the gene products in ahsv infected vero cells. | the smallest genome segment of african horsesickness virus (ahsv), segment 10 (s10), encodes two minor nonstructural proteins, ns3 and ns3a. while the cognate bluetongue virus (btv) proteins have been suggested to play a role in the release of virus particles from infected cells, no function has yet been ascribed to ahsv ns3/ns3a. when the ahsv-3 s10 gene was expressed in a baculovirus system only a single ns3 protein (24 k) was synthesized, at lower levels than expected. it was shown that this ... | 1995 | 7710356 |
| nematocera (ceratopogonidae, psychodidae, simuliidae and culicidae) and control methods. | the biology, veterinary importance and control of certain nematocera are described and discussed. culicoides spp. (family ceratopogonidae) transmit the arboviruses of bluetongue (bt), african horse sickness (ahs), bovine ephemeral fever (bef) and akabane. some other arboviruses have been isolated from these species, while fowl pox has been transmitted experimentally by culicoides. these insects are vectors of the parasitic protozoans leucocytozoon caulleryi and haemoproteus nettionis, and the pa ... | 1994 | 7711309 |
| bluetongue virus. | bluetongue (blu) is a noncontagious viral disease. the virus is a member of the orbivirus genus and serves as the prototype virus of the genus. blu is primarily a disease of domestic ruminants, some wild ruminants, and, recently, domestic dogs. the disease is caused by 1 of 24 different serotypes of virus that are distributed worldwide. this article reviews the viruses, their distribution, clinical signs, pathogenesis, and the roles they play in reproductive failure. | 1994 | 7728636 |
| differentiation of cognate dsrna genome segments of bluetongue virus reassortants by temperature gradient gel electrophoresis. | the analysis of reassortant viruses has been a valuable tool in the investigation of protein interaction and function in double-stranded (ds) rna virus research. the differentiation of cognate dsrna genome segments of reassortants is conventionally achieved by sds-polyacrylamide gel electrophoresis (sds-page). however, due to a high degree of sequence homology among different bluetongue virus (btv) serotypes, it is not uncommon to find that certain cognate dsrna segments cannot be differentiated ... | 1995 | 7738141 |
| the transmission and geographical spread of african horse sickness and bluetongue viruses. | african horse sickness virus (ahsv) and bluetongue virus (btv) are dsrna viruses within the genus orbivirus. both are able to cause non-contagious, infectious arthropod-borne diseases in their respective vertebrate hosts. ahsv infects equines and occasionally dogs, whereas btv replicates in ruminants. the disease caused by ahsv is usually at its most severe in horses, whereas certain breeds of sheep are particularly sensitive to btv infection. ahsv is endemic in sub-saharan africa but periodical ... | 1995 | 7741589 |
| picture story. bluetongue's sticky bristle. | | 1995 | 7749915 |
| high-level expression of five foreign genes by a single recombinant baculovirus. | co-infection with several viruses is often used to achieve simultaneous expression of several proteins. from co-infections involving several viruses, the ratio of proteins synthesized in individual cells can be very variable. this is disadvantageous where proteins are needed to interact to provide a maximum yield of a complex product. multiple-gene-expression vectors offer an alternative to co-infections. they enable reproducible ratios of products to be provided in each infected cell. until rec ... | 1995 | 7758961 |
| isolation of multiple serotypes of bluetongue virus from sentinel livestock in malaysia. | sixteen isolations of bluetongue virus (btv) were made from the heparinised bloods of 4 groups of cattle and sheep in peninsular malaysia. these viruses were typed as btv serotypes 1, 2, 3, 9, 16 and 23. multiple serotypes of btv are apparently endemic in malaysia and in other countries in the region. | 1995 | 7770950 |
| pathogenesis of bluetongue virus infection of cattle. | | 1995 | 7775242 |
| bluetongue and douglas virus activity in new south wales in 1989: further evidence for long-distance dispersal of the biting midge culicoides brevitarsis. | infection of cattle with bluetongue and douglas viruses was detected on the central and southern coast of new south wales from january to april 1989. bluetongue virus infection was found well south of areas of expected occurrence. evidence is presented to support wind-borne dispersal of infected vectors, culicoides brevitarsis, southwards from the hunter valley. | 1995 | 7779035 |
| complete nucleotide sequence of rna segment 3 of bluetongue virus serotype 2 (ona-a). phylogenetic analyses reveal the probable origin and relationship with other orbiviruses. | the nucleotide sequence of the rna segment 3 of bluetongue virus (btv) serotype 2 (ona-a) from north america was determined to be 2772 nucleotides containing a single large open reading frame of 2703 nucleotides (901 amino acid). the predicted vp3 protein exhibited general physiochemical properties (including hydropathy profiles) which were very similar to those previously deduced for other btv vp3 proteins. partial genome segment 3 sequences, obtained by polymerase chain reaction (pcr) sequenci ... | 1995 | 7785314 |
| anti-idiotypic antibody as potential serodiagnostic reagent for detection of bluetongue virus infection. | polyclonal anti-idiotypic antibodies (anti-ids) were generated by the sequential immunization of rabbits with three mouse monoclonal antibodies (mab1s) specific for a major bluetongue virus (btv) protein, vp7. the anti-ids, designated rab2s, recognized idiotopes which were located within or near the antigen-combining sites of the mab1s and were associated with both heavy and light chains of mab1s. rab2s inhibited the mab1s from binding to btv antigens, and their interaction with mab1s was inhibi ... | 1995 | 7790450 |
| crystallization and preliminary x-ray analysis of the core particle of bluetongue virus. | core particles of bluetongue virus serotype 1 (south africa) have been crystallized. the crystals, which grow up to 0.8 mm in diameter, belong to a primitive orthorhombic space group and have point group symmetry 222. the unit cell dimensions are 754 x 796 x 823 a3 and the crystallographic asymmetric unit contains one-half of a core particle. the best crystals diffract strongly to 4.8 a bragg spacings, which is the maximum resolution to which we can measure data with the detectors available, sug ... | 1995 | 7793074 |
| fecundity and proportions of gravid females in populations of the bluetongue vector culicoides imicola (diptera: ceratopogonidae) and several other species in israel. | the gravid proportions of five culicoides spp. in israel were determined based on a suction light trap placed above calves in a cowshed and on two similar traps hung in a eucalyptus tree at elevations of 1.4 and 26 m. in the cowshed, the proportion of gravid culicoides distinctipennis austen showed no significant variation between seasons; c. imicola kieffer (the dominant species) was caught in significantly smaller proportions in winter; c. schultzei gp (second most dominant) showed no signific ... | 1994 | 7815395 |
| complex interactions between vectors and pathogens: culicoides variipennis sonorensis (diptera: ceratopogonidae) infection rates with bluetongue viruses. | two laboratory colonies of culicoides variipennis sonorensis wirth & jones were allowed to take blood meals containing the five u.s. serotypes (2, 10, 11, 13, and 17) of bluetongue (blu) virus. after 14 d of extrinsic incubation, the flies were assayed for the presence of virus using an antigen capture enzyme-linked immunosorbent assay (elisa). there was a significant effect of the serotype on infection of c. v. sonorensis with blu virus. there was no significant difference in infection of the t ... | 1994 | 7815405 |
| the crystal structure of bluetongue virus vp7. | bluetongue virus (btv), a representative of the orbivirus genus of the reoviridae, is considerably larger (at 80 nm across), and structurally more complex, than any virus for which we have comprehensive structural information. orbiviruses infect mammalian hosts through insect vectors and cause economically important diseases of domesticated animals. they possess a segmented double-stranded rna genome within a capsid composed of four major types of polypeptide chains. an outer layer of vp2 and vp ... | 1995 | 7816101 |
| validation of a quantitative elisa for comparison of monoclonal antibody affinities for isolates of bluetongue virus. | the ability of an elisa-based system to reliably assess the relative affinities of separate monoclonal antibodies (mabs) for heterologous isolates of bluetongue virus (btv) was tested. the demonstration that a btv serogroup-specific mab (20e9b7g2) possessed equivalent binding properties with the majority of virus isolates tested, permitted a reliable estimation of the relative amount of individual test viruses present in the assay. subsequent correction for the relative amounts of test viruses a ... | 1994 | 7822840 |
| a rapid indirect elisa for the serogrouping of australian orbiviruses. | this communication describes the development and evaluation of a simple and rapid method for the classification of australian orbiviruses into one of seven established serogroups (i.e. bluetongue, epizootic haemorrhagic disease of deer, palyam, eubenangee, corriparta, wallal, warrego) or an 'ungrouped' category. the australian orbivirus serogrouping elisa (sg-elisa) utilised a sodium deoxycholate-treated cell lysate preparation from infected bhk cells which was subsequently probed in an indirect ... | 1994 | 7829593 |
| sequence analysis of the non-structural protein 2 from epizootic hemorrhagic disease viruses. | the non-structural protein 2 (ns2) of epizootic hemorrhagic disease virus serotype 1 (ehd-1) was cloned and sequenced. the ns2 gene was found to be 1185 bp containing a single open reading frame that encodes a 376 amino acid protein. a 97% nucleic acid identity was found between ehd-1 and a previously published ns2 sequence of ehd-2. only a 60% nucleic acid identity was found between ehd and the bluetongue virus (btv) serogroup. comparison of the deduced amino acid sequences revealed 97% identit ... | 1994 | 7831965 |
| phylogenetic relationships of the vp2 protein of a virulent isolate of bluetongue virus (btv-23) compared to those of 6 other btv serotypes. | to determine the genetic relationship of the virulent australian bluetongue virus serotype 23 with that of other serotypes and to identify the extent and nature of the antigenic variation among seven serotypes of bluetongue virus (btv), the complete nucleotide sequence was determined for cdna clones representing the l2 dsrna of btv-23, the gene that codes for the outer capsid neutralization antigen (vp2). the predicted amino acid sequence of the protein was compared with the vp2 sequences of the ... | 1994 | 7831967 |
| experimentally induced infection with bluetongue virus serotype 11 in cows. | the consequences of inoculation of bluetongue virus (btv) serotype 11 into 16 susceptible cows either at the time of breeding or at specified stages of pregnancy were studied. the cows were free of btv or epizootic hemorrhagic disease virus, and none had antibodies to btv before virus inoculation. a group of 4 cows was mated naturally to a bull reported to shed btv-11 (co75b300 strain) in the semen. the bull was suspected of infecting cows at mating with btv-11, which subsequently transplacental ... | 1994 | 7879975 |
| comparison of immunogold methodologies for the detection of low copy number viral antigens in bluetongue virus (btv)-infected cells. | cells infected with bluetongue virus (btv) were prepared for immunocytochemistry by freeze substitution, the progressive lowering of temperature technique and the tokuyasu method. sections containing virus-infected cells were incubated with specific monoclonal antibodies and colloidal gold probes to detect virus antigens of varying copy number; these btv proteins were structural proteins vp2 and vp7 and the non-structural protein ns2. protocols compared in this study represented those used in la ... | 1994 | 7881897 |
| a congenital abnormality of calves, suggestive of a new type of arthropod-borne virus infection. | about 1000 calves with a congenital disease were born in kagoshima prefecture, japan, between october 1990 and october 1991, the peaks of the epidemic being in march and july 1991. of 85 abnormal calves examined pathologically and serologically, 70 appeared to have been suffering from a viral disease. of these 70 animals, 17 had lesions bearing some resemblance to those of the diseases produced by akabane, chuzan, aino, bluetongue and bovine viral diarrhoea-mucosal disease viruses-diseases known ... | 1994 | 7884059 |
| dynamics of viral spread in bluetongue virus infected calves. | the kinetics of viremia and sites of viral replication in bluetongue virus (btv) infected calves were characterized by virus isolation, serology and immunofluorescence staining procedures. in addition, the role of the regional lymph node and lymphatics draining inoculated skin in the pathogenesis of btv infection was determined by analyzing efferent lymph collected from indwelling cannulas. viremia persisted for 35 to 42 days after inoculation (dai) and virus co-circulated with neutralizing anti ... | 1994 | 7941299 |
| fine mapping of a surface-accessible, immunodominant site on the bluetongue virus major core protein vp7. | the 349-amino-acid major core protein vp7 of bluetongue virus (btv) is both the most abundant viral structural protein and the major immunogenic serogroup-reactive viral antigen. previous studies indicated that a conformation-dependent antigenic site, defined by the vp7-specific monoclonal antibody 20e9/b7/g2(20e9), was accessible from the virus surface and that the binding of the monoclonal antibody to this epitope could be blocked specifically by antisera raised against different serotypes of ... | 1994 | 7941351 |
| expression of the outer capsid proteins vp2 and vp5 of bluetongue virus in saccharomyces cerevisiae. | cdnas transcribed from bluetongue virus serotype 1 (australia) ds rna 2 and ds rna 6 coding for the major neutralising antigen vp2 and the outer capsid protein vp5, respectively, were amplified in polymerase chain reactions and ligated downstream of the copper-inducible metallothionein promoter in the yeast expression plasmid pyelc5. saccharomyces cerevisiae transformed with the recombinant plasmid pyelc5-vp2 expressed full-length vp2 only following induction with 1 mm cuso4 and reached the maxi ... | 1994 | 7941697 |
| canine fatalities associated with the use of a modified live vaccine administered during late stages of pregnancy. | | 1994 | 7948206 |
| [epidemiologic study of bluetongue in sheep, cattle and different species of wild animals in the ivory coast]. | between 1992 and 1993, a serological survey was conducted in côte d'ivoire on 623 sera from sheep, 215 sera from cattle and 211 sera from wild herbivores. these sera were tested for bluetongue virus (btv) antibodies using an agar gel immunodiffusion test. the purpose of this survey was twofold: to establish the incidence of bluetongue in the country, and to analyse the putative role of btv in the reproductive pathology of sheep. seroprevalence was 52 +/- 4% in sheep, 95 +/- 3% in cattle, and 56 ... | 1994 | 7949349 |
| isolation of bluetongue virus from sheep in rajasthan state, india. | a cytopathic agent was isolated in a baby hamster kidney (bhk)-21 cell-line from blood samples of cross-bred sheep showing typical bluetongue symptoms at avikanagar in rajasthan state, india. the cytopathic agent was identified as a bluetongue virus (btv) by immunofluorescence, the immunoperoxidase test and electron microscopy of bhk-21 cells infected with the new isolate. the new isolate was typed as btv serotype 1. | 1994 | 7949364 |
| bluetongue virus: contamination of vaccine. | | 1994 | 7961063 |
| the use of an indirect elisa with protein g-peroxidase conjugate and a blocking elisa to demonstrate recent bluetongue infection in sheep. | the humoral immune response of sheep infected with bluetongue virus serotypes 3, 9 and 16 was monitored by plaque inhibition (pi), blocking elisa (belisa) and indirect elisa over a period of 63 days post-infection. results indicated that testing of a single plasma or serum sample by both a belisa and an indirect elisa using a recombinant streptococcal protein g (prg) peroxidase conjugate enabled an assessment of the proximity of a recent infection based on the failure of prg to bind ovine igm cl ... | 1994 | 7962260 |
| long-lasting protection of sheep against bluetongue challenge after vaccination with virus-like particles: evidence for homologous and partial heterologous protection. | insect cells co-infected with appropriate recombinant baculoviruses synthesize double-shelled, virus-like particles (vlps) with bluetongue virus (btv) vp2 proteins representing serotype 1 (btv-1), 2 (btv-2), 10 (btv-10), 13 (btv-13) or 17 (btv-17) as previously reported for btv-10 (french, t.j., marshall, j.j.a. and roy, p. j. virol. 1990, 64, 5696-5700). the derived particles were purified and used to vaccine sheep, either as single vlp types (btv-10, btv-17) or as a combination of all five ser ... | 1994 | 7975859 |
| identification of an amino acid on vp2 that affects neutralization of bluetongue virus serotype 10. | genome segment 2, coding for the vp2 protein, of a neutralization resistant variant was compared to segment 2 of the bluetongue virus (btv) serotype 10 parent from which the variant was derived. full-length double-stranded cdna of btv segment 2 rna, which was prepared by reverse transcription, was used as template to prepare overlapping subgenomic cdna products by pcr. purified pcr cdna fragments were sequenced by the dideoxy chain termination reaction. each base was determined an average of 3.7 ... | 1994 | 7975878 |
| host factors affecting seroprevalence of bluetongue virus infections of cattle. | results of testing of 19,731 samples from a serologic survey of cattle with bluetongue virus (btv) infections in australia were analyzed for association between age, species, or sex and test result. bivariate analysis indicated that all 3 host factors were associated with test result. after adjusting for confounding caused by the location of each animal in the study (high, moderate, and low btv prevalence regions), cattle > or = 4 years old had an odds ratio of 4.33 (95% confidence interval, 3.9 ... | 1994 | 7978629 |
| vaccinia virus expression of the vp7 protein of south african bluetongue virus serotype 4 and its use as an antigen in a capture elisa. | recombinant vaccinia viruses expressing the vp7 core protein of south african bluetongue virus serotype 4 (sa-btv4) were identified by polymerase chain reaction amplification. expression of vp7 was verified by radio-immunoprecipitation and a f(ab')2-based elisa. antibodies to vp7 were detected in sera from sheep that had been infected with 20 different virulent btv serotypes by using the vaccinia virus (vv) expressed vp7 as antigen in a capture elisa. f(ab')2-immobilised vv-expressed sa-btv4 vp7 ... | 1994 | 7979976 |
| evidence of natural bluetongue virus infection among african carnivores. | bluetongue is an international office of epizootics list a disease described as the century's most economically devastating affliction of sheep. bluetongue (blu) viruses were thought to infect only ruminants, shrews, and some rodents, but recently, inadvertent administration of blu virus-contaminated vaccine resulted in mortality and abortion among domestic dogs. we present evidence of natural blu virus infection among african carnivores that dramatically widens the spectrum of susceptible hosts ... | 1994 | 7985748 |
| structure of correctly self-assembled bluetongue virus-like particles. | bluetongue virus-like particles (vlps), synthesized by coexpression of vp2, vp3, vp5, and vp7 using recombinant baculoviruses, have been examined by cryoelectron microscopy and image analysis. the 3-d reconstruction of these vlps reveals an icosahedral structure 86 nm in diameter with essentially the same features as for the native bluetongue virus (btv) particle. the vlp is thus shown to contain the four constituent proteins as the native virus particle, with each of the protein positions highl ... | 1994 | 7986645 |
| the impact of bluetongue virus on reproduction. | bluetongue virus has been recognized as an important noncontagious, arthropodborne infectious viral disease of ruminants. 24 different serotypes of virus have been recognized worldwide. the most severe clinical disease has been associated with severe clinical disease in sheep and some free ranging wild ruminants. a number of reports have implicated the viruses as causing reproductive disorders in both males and females. the bluetongue related reproductive disorders include early embryonic deaths ... | 1994 | 8001344 |
| the pathogenesis and immunology of bluetongue virus infection of ruminants. | bluetongue (blu) virus is transmitted from infected to susceptible ruminants by hematophagous vector midges (culicoides species). cattle are important reservoir hosts of the virus because infection typically is asymptomatic and characterized by prolonged cell associated viremia, and because at least some species of insect vector preferentially feed on cattle. interaction of blu virus with the cell membrane of erythrocytes in infected cattle likely facilitates both prolonged viremia as well as in ... | 1994 | 8001345 |
| the epidemiology of bluetongue. | the perception that bluetongue virus (btv), once introduced to a country, would decimate its sheep industry, grew from the acceptance in the late 1950s that it was an emerging virus with africa as its source. epidemiological studies in the 1960s and early 1970s confirmed that the geographic distribution of btv infections included regions of the world, outside the traditionally defined areas where bt was observed. this was interpreted at the time as representing serious and rapid spread of the vi ... | 1994 | 8001346 |
| bluetongue: laboratory diagnosis. | definitive diagnosis of bluetongue virus (btv) infection, often subclinical in domestic and wild ruminant relies heavily on laboratory techniques for btv isolation and demonstration of btv antigens, viral nucleic acids and antibodies. the virus can be isolated from blood components, mainly the erythrocyte fraction, collected from affected animals during the period of febrile response. semen collected from male animals at the peak of viremia and tissues from affected animals and fetuses may also ... | 1994 | 8001347 |
| african horse sickness virus structure. | african horse sickness virus (ahsv), of which there are nine serotypes (ahsv-1, -2, etc.), is a member of orbivirus genus within the reoviridae family. both in morphology and molecular constituents ahsv particles are comparable to those of bluetongue virus (btv), the prototype virus of the genus. the two viruses have seven structural proteins (vp1-7) organized in two layered capsid. the outer capsid is composed of vp2 and vp5. the inner capsid, or core, is composed of two major proteins, vp3 and ... | 1994 | 8001348 |
| detection of bluetongue virus in the blood of inoculated calves: comparison of virus isolation, pcr assay, and in vitro feeding of culicoides variipennis. | the interval after infection when bluetongue virus (btv) was present in the blood of calves inoculated with btv serotype 10 (btv 10) was evaluated by virus isolation (vi) in embryonated chicken eggs (ece), btv-specific polymerase chain reaction (pcr), and in vitro blood feeding of vector culicoides variipennis (c.v.) sonorensis. btv nucleic acid was detected by pcr in blood cells for 16 to 20 weeks after infection whereas infectious virus was detected by vi in ece for 2 to 8 weeks. btv was detec ... | 1994 | 8002778 |
| rapid detection of african horsesickness virus by the reverse transcriptase polymerase chain reaction (rt-pcr) using the amplimer for segment 3 (vp3 gene). | the complete sequence of the major core protein (vp3) gene of african horsesickness virus serotype 4 (ahsv-4; vaccine strain) was determined by analysis of a complete cdna clone representing segment 3. the rna was 2,789 bp long and a comparison of its sequence with that of bluetongue virus serotype 10 (btv-10) revealed 58% nucleotide similarity. based on these data, the reverse transcriptase-polymerase chain reaction (rt-pcr) technique was applied to the specific detection of ahsv using a pair o ... | 1994 | 8002793 |
| distribution of bluetongue virus in turkey, 1978-81. | information about the distribution of bluetongue in turkey during 1978-81 has been obtained by serological surveys in cattle, sheep and goats. the group-specific immunodiffusion test was used to identify the presence of bluetongue virus (btv) in a given province and the type-specific microneutralization test to decide which virus types had been in circulation. by drawing sera from accurately aged donor animals in may and august 1980, it was possible to draw up a general outline of the distributi ... | 1994 | 8005228 |
| the pathogenesis of bluetongue virus infection of bovine blood cells in vitro: ultrastructural characterization. | cattle are proposed to be reservoir hosts of bluetongue virus (btv) because infected animals typically have a prolonged cell-associated viremia. enriched populations of bovine monocytes, erythrocytes and lymphocytes were inoculated with btv serotype 10 (btv 10) and the infected cells then were examined by transmission electron microscopy to characterize the interaction of btv with bovine blood cells. replication of btv 10 in monocytes and stimulated (replicating) lymphocytes was morphologically ... | 1994 | 8031234 |
| climatic factors associated with the prevalence of bluetongue virus infection of cattle herds in queensland, australia. | the prevalence of bluetongue virus in 410 cattle herds in queensland, australia, was estimated by using the bluetongue virus agar gel immunodiffusion test, and 18 climatic variables were estimated for the location of each herd. temperature and rainfall were the factors most closely associated with the prevalence of bluetongue virus in the herds, and the simplest relationship which explained the most variability in the prevalence included the average daily maximum temperature and the average annu ... | 1994 | 8036770 |
| purification and properties of virus particles, infectious subviral particles, cores and vp7 crystals of african horsesickness virus serotype 9. | methods were developed for the purification, at high yield, of four different particle types of african horsesickness virus serotype 9 (ahsv-9). these products included virus particles purified on cscl gradients which contain proteins apparently directly comparable to those of bluetongue virus (vp1 to vp7); virus particles purified on sucrose gradients which also contain, as a variable component, protein ns2; infectious subviral particles (isvps), containing chymotrypsin cleavage products of vp2 ... | 1994 | 8046387 |
| phylogenetic characterisation of bluetongue viruses from naturally-infected insects, cattle and sheep in australia. | the polymerase chain reaction was used to detect the presence of bluetongue virus (btv) in a number of clinical and insect samples collected in the northern territory of australia. sequence analyses of the amplified btv genes differentiated endemic australian and exotic viruses. two potential exotic btv were detected as a result of pcr analyses of blood from sentinel animals and of the insect vector, culicoides wadai. the detection of btv in c wadai was the first direct demonstration of the pres ... | 1994 | 8048903 |
| bluetongue virus infection in sheep: haematological changes and detection by polymerase chain reaction. | eight sheep vaccinated with 10(6) pfu of attenuated australian bluetongue virus serotype 23 (btv 23a) and eight btv-free sheep were challenged with virulent btv 23. there was little subsequent variation in the mean clinical score, or in the mean lymphocyte and platelet concentrations in the peripheral blood of the eight vaccinated sheep. there was a marked thrombocytopenia and lymphopenia in the naive sheep as the mean lymphocyte and platelet concentrations fell to a minimum at days 8 and 11 aft ... | 1994 | 8048910 |
| infection of culicoides brevitarsis and c. wadai (diptera: ceratopogonidae) with four australian serotypes of bluetongue virus. | field collected culicoides brevitarsis kieffer and c. wadai kitaoka were fed on sheep that had been artificially infected with a field-isolate of either bluetongue virus serotype 3 (blu3), blu9, blu16, or blu23. feeding rates averaged 11.9% but were variable. survival of midges during incubation tended to be enhanced by the addition of antibiotics and fungicide to the diet. attempts to transmit virus to sheep by the bite of these two species were unsuccessful. both c. brevitarsis and c. wadai ha ... | 1994 | 8057311 |
| abortion and death in pregnant bitches associated with a canine vaccine contaminated with bluetongue virus. | | 1994 | 8063596 |
| bluetongue virus infection in pregnant ewes. | inoculation of 53 ewes after 35, 45, 60, or 80 days of gestation with bluetongue virus serotypes 10, 11, 13, or 17, or with epizootic hemorrhagic disease virus serotypes 1 or 2, resulted in overt clinical disease in the 47 ewes inoculated with bluetongue virus but not in the 6 ewes inoculated with epizootic hemorrhagic disease virus. none of the lambs produced by these ewes had developmental defects or any evidence of persistence of viremia. | 1994 | 8067615 |
| diagnostic analysis of the prolonged bluetongue virus rna presence found in the blood of naturally infected cattle and experimentally infected sheep. | bluetongue virus (btv) rna was detected by the polymerase chain reaction (pcr) in the blood of 24 naturally infected cattle as long as 160 days after the estimated date of infection. blood samples from these animals and from 10 experimentally btv-infected sheep, which also exhibited a prolonged hematologic btv rna presence, were concurrently evaluated for viral infectivity. infectivity analyses were conducted using the sentinel sheep inoculation and embryonated chicken egg inoculation procedures ... | 1994 | 8068742 |
| detection of epizootic hemorrhagic disease virus serotypes 1 and 2 in cell culture and clinical samples using polymerase chain reaction. | the potential for the use of the polymerase chain reaction (pcr) in detecting epizootic hemorrhagic disease virus (ehdv) ribonucleic acid in cell cultures and clinical samples was studied. using oligoribonucleotide primers selected from genome segment 6 of ehdv-2 (alberta strain), the pcr-based assay resulted in a 387-base pair (bp) pcr product. ehdv rna from us prototype serotypes 1 and 2 and a number of ehdv field isolates, propagated in cell cultures, were detected by this ehdv pcr-based assa ... | 1994 | 8068743 |
| identification of african horse sickness virus in cell culture using a digoxigenin-labeled rna probe. | a digoxigenin-labeled rna probe was synthesized from a plasmid containing a portion of the african horse sickness virus (ahsv) serotype 4 genome segment coding for nonstructural protein 1. in an in situ hybridization procedure, this probe hybridized successfully to vero cells infected with each of the 9 serotypes of ahsv. there was no hybridization with noninfected cell cultures or cell cultures infected with bluetongue virus. | 1994 | 8068745 |
| the complete sequences of african horsesickness virus serotype 4 (vaccine strain) rna segment 2 and 6 which encode outer capsid protein. | the complete sequences of rna segment 2 and segment 6 of african horsesickness virus serotype 4 (ahsv-4) vaccine strain were determined from cdna clones inserted into pbr 322. the rnas of segment 2 and 6 are 3229, 1566 bp long respectively and both contain an open reading frame encoding proteins vp2 and vp5 of 1060, 505 amino acid residues. the estimated molecular weight of vp2 was 124,178 dalton and that of vp5 was 56,793 dalton. their noncoding end sequences were 5'gtttaa . . . and . . . acata ... | 1994 | 8075221 |
| major core protein vp7 of australian bluetongue virus serotype 15: sequence and antigenicity divergence from other btv serotypes. | full-length cdna of the rna genome segment coding for the major core protein vp7 of australian bluetongue virus serotype 15 (btv-15) has been isolated by reverse transcription-pcr cloning. comparative analysis indicated that the btv-15 vp7 sequence had diverged significantly from that of other members of the btv serogroup. at the amino acid level, btv-15 vp7 exhibited sequence identities of 80 to 84% with vp7 molecules of other serotypes, significantly lower than the sequence identities of betwe ... | 1994 | 8077943 |
| the smallest gene of the orbivirus, epizootic hemorrhagic disease, is expressed in virus-infected cells as two proteins and the expression differs from that of the cognate gene of bluetongue virus. | the smallest gene (s10) of the virus of epizootic hemorrhagic disease of deer (ehd, serotype 2) is expressed as two proteins in virus-infected cells. by contrast, the non-structural proteins (ns3 and ns3a) encoded in the smallest gene of bluetongue (bt) viruses are difficult to detect in virus-infected cells. the nucleotide sequence of s10 of ehdv-2 contains two in-frame initiation codons which allow for translation of proteins of mol. wt. 25503 and 23921 analogous to ns3 and ns3a of bt viruses. ... | 1994 | 8079516 |
| analyses and conservation of sequences among the cognate l3 segments of the five united states bluetongue viruses. | we determined the complete nucleotide sequences of the cognate l3 double-stranded rna (ds-rna) segments of bluetongue virus (btv) serotypes 2, 11, and 13 encoding the major viral inner capsid protein, vp3. each cognate l3 segment was 2772 nucleotides long and contained a single open reading frame (orf) with an initiation codon at nucleotides #18-20 and a termination codon at nucleotides #2721-2723. this orf can encode the 901-amino acid vp3 protein (103 kda) with a calculated isoelectric point o ... | 1994 | 8079518 |
| subcore- and core-like particles of broadhaven virus (brdv), a tick-borne orbivirus, synthesized from baculovirus expressed vp2 and vp7, the major core proteins of brdv. | the genes encoding the two major core proteins (vp2 and vp7) of broadhaven (brd) virus, a tick-borne orbivirus, were inserted into the genome of autographa californica nuclear polyhedrosis virus (acnpv) under the control of copies of the acnpv polyhedrin promoter to produce two recombinant baculoviruses. infection of spodoptera frugiperda (sf) cells with a recombinant acnpv that synthesized brdv vp2 produced large numbers of brdv subcore-like particles. co-infection of cells with the two recombi ... | 1994 | 8079519 |
| bluetongue research in australia--1993. | | 1994 | 8080408 |
| cryoelectron microscopy of macromolecular complexes. | although there are many macromolecular complexes which play extremely important roles in biology, and despite continued progress in x-ray crystallographic and nmr methods, it is still very difficult to obtain atomic level structural information about such large assemblies. it is now clear that a powerful approach is to combine structural information obtained at different levels. cryoelectron microscopy of frozen-hydrated samples together with computer based 3-d reconstruction can give structural ... | 1994 | 8087070 |
| the use of discriminant analysis in predicting the distribution of bluetongue virus in queensland, australia. | the climatic variables that were most useful in classifying the infection status of queensland cattle herds with bluetongue virus were assessed using stepwise linear discriminant analysis. a discriminant function that included average annual rainfall and average daily maximum temperature was found to correctly classify 82.6% of uninfected herds and 72.4% of infected herds. overall, the infection status of 74.1% of herds was correctly classified. the spatial distribution of infected herds was fou ... | 1994 | 8091641 |
| colorimetric diagnosis of prolonged bluetongue viremia in sheep, using an enzyme-linked oligonucleotide sorbent assay of amplified viral nucleic acids. | each of 5 us-origin serotypes of bluetongue virus (btv) was inoculated into a separate pair of sheep. the duration of each animal's ensuing viremia was monitored, using a btv serogroup-specific nested polymerase chain reaction (pcr) method and an embryonating chicken egg (ece) inoculation procedure. mean duration of viremia was 100 and 38 days for the pcr and ece methods, respectively. this difference was significant (p < 0.001) and documents a more prolonged viremia in virus-exposed sheep than ... | 1993 | 8116932 |
| mutation of either of two cysteine residues or deletion of the amino or carboxy terminus of nonstructural protein ns1 of bluetongue virus abrogates virus-specified tubule formation in insect cells. | virus-specific tubules are characteristic of orbivirus infections and are likely to play an important role in virus morphogenesis. it has been shown that for bluetongue virus (btv), the prototype orbivirus in the family reoviridae, the virus-encoded ns1 protein forms tubules in insect cells when the btv segment m6 gene is expressed by using a baculovirus vector. to understand the function of ns1 tubules and to identify the sequences involved in their polymerization, a series of mutant ns1 genes ... | 1994 | 8139001 |
| deletion and mutational analyses of bluetongue virus ns2 protein indicate that the amino but not the carboxy terminus of the protein is critical for rna-protein interactions. | genome segment 8 (s8) of bluetongue virus serotype 10 (btv-10) encodes the nonstructural protein ns2. this protein, which has single-stranded rna (ssrna) binding capacity, is found in btv-infected cells in the form of virus inclusion bodies (vibs). to identify the domain(s) important for rna binding and oligomerization of the protein, a number of deletions were made in regions of the gene that code for either the amino or carboxy terminus of the protein. the modified genes were cloned into and e ... | 1994 | 8139002 |
| 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 |
| antibody prevalence of eight ruminant infectious diseases in california mule and black-tailed deer (odocoileus hemionus). | we tested 276 sera from 18 free-ranging black-tailed and mule deer (odocoileus hemionus) herds in california (usa) collected from 1987 to 1991 in five biogeographical habitat types, for antibodies against eight infectious disease agents. overall antibody prevalence was 56% for anaplasma marginale, 31% for borrelia burgdorferi, 16% for bluetongue virus serotype 17, 15% for epizootic hemorrhagic disease virus, 7% for coxiella burnetii and toxoplasma gondii, respectively, and 0% for bovine leukosis ... | 1994 | 8151824 |
| serologic detection of bluetongue virus infection of black-tailed deer: comparison of serum neutralization, agar gel immunodiffusion, and competitive elisa assays. | three adult black-tailed deer (odocoileus hemionus columbianus) and four fawns were inoculated with bluetongue virus (btv) serotype 10 or 17, or epizootic hemorrhagic disease virus (ehdv) serotype 1. animals were bled at irregular intervals thereafter and the presence of virus-specific antibodies in serum determined by agar gel immunodiffusion (agid), serum neutralization (sn) and competitive enzyme-linked immunosorbent assay (c-elisa) tests. serum antibodies to btv were detected in all three te ... | 1994 | 8151833 |
| dissecting the assembly of orbiviruses. | virus assembly within infected cells involves a precise sequence of macromolecular interactions. to unravel the individual steps involved in the assembly of a complete virion of bluetongue virus, we have engineered a series of recombinant baculoviruses to make multicomponent structures resembling virus structures. when combined with cryoelectron microscopy and image processing techniques the data reveal the organization and assembly of the various components of this virus. | 1993 | 8162414 |
| heterogeneity of the l2 gene of field isolates of bluetongue virus serotype 17 from the san joaquin valley of california. | genome segment 2 (l2) from six field isolates of bluetongue virus (btv) serotype 17 was sequenced by cycling sequencing after the amplification of the viral cdna by the polymerase chain reaction. the viruses were isolated from sheep, cattle and a goat in the san joaquin valley of california during the years 1981 and 1990. these viruses exhibit divergent patterns of neutralization with btv 17-specific monoclonal antibodies. the six l2 genes of the btv 17 field isolates all encode a protein of 955 ... | 1994 | 8165870 |
| bluetongue virus isolations from vectors and ruminants in central america and the caribbean. interamerican bluetongue team. | a regional prospective study of the epidemiology of bluetongue virus (btv) serotypes covering 11 countries in central america and the caribbean took place between 1987 and 1992. active surveillance revealed btv infection to be endemic in the absence of confirmed indigenous cases of bluetongue. during the 6-year span of the study, over 300 btv isolations were obtained from cattle and sheep. results of the earlier years of the study were summarized, and surveillance activities in the concluding mo ... | 1994 | 8172409 |