Virology in horses encompasses the study of viruses that affect equine species, including their biology, transmission, and impact on horse health. This field investigates viral pathogens that can lead to a range of diseases, from respiratory infections to neurological disorders. Common viruses affecting horses include equine influenza virus, equine herpesvirus, and West Nile virus. Understanding these viruses involves examining their genetic makeup, modes of transmission, and interactions with the equine immune system. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, and control measures of viral infections in horses.
Studdert MJ, Fitzpatrick DR, Horner GW, Westbury HA, Gleeson LJ.Representative strains of EHV isolated from an aborted foetus and from a horse with rhinopneumonitis in New Zealand had restriction endonuclease DNA fingerprints typical of those usually associated with these syndromes elsewhere and now designated EHV1 and 4 respectively. EHV1 was isolated from the brain and spinal cord of a 4-year-old gelding that died of myeloencephalitis. A mare on the same farm, at about the same time as the gelding developed myeloencephalitis, aborted and EHV1 was isolated from the tissues of the aborted foetus. Restriction endonuclease DNA fingerprints of the viruses iso...
O'Niell FD, Issel CJ, Henk WG.Organ cultures of equine fetal tracheal and nasal turbinate epithelium were inoculated with equine influenza virus-A1 (EIV-A1), equine herpesvirus-1 (EHV-1), or equine rhinovirus-1 (ERV-1). Infected organ cultures were processed for scanning and transmission electron microscopy at various intervals and were compared with noninfected controls. Organ cultures inoculated with ERV-1 appeared normal with the exception of rare island-like lesions in infected nasal turbinate. Virus particles were not seen in thin sections of organ cultures infected with ERV-1. The EHV-1 caused extensive loss of the e...
O'Niell FD, Issel CJ.Growth kinetics of equine influenza virus-A1, equine herpesvirus-1, and equine rhinovirus-1 were determined in susceptible cell monolayers and in organ cultures of equine fetal tracheal and nasal turbinate epithelium. Equine influenza virus-A1 was replicated in cell and organ cultures and was released more readily and for longer periods from nasal turbinate epithelium than from tracheal epithelium. Equine herpesvirus-1 was also replicated in cell and organ cultures. During the first 24 hours after inoculation, equine herpesvirus-1 was released more readily from tracheal epithelium than from na...
Edington N, Wright JA, Patel JR, Edwards GB, Griffiths L.Equine adenovirus 1 was recovered after four to six passages from two out of three cases of cauda equina neuritis (CEN) using kidney monolayers. Similar treatment of lumbo-sacral spinal cord from six normal horses did not yield adenovirus. All three cases of CEN had antibodies to the neuritogenic myelin protein P2 while immunofluorescence demonstrated that autologous IgG bound to the myelin of affected nerves. Adenovirus was not detected in neural tissue by immunofluorescence.
Hildreth SW, Beaty BJ, Maxfield HK, Gilfillan RF, Rosenau BJ.Enzyme immunoassays (EIAs) for eastern equine encephalomyelitis (EEE) and Highlands J (HJ) virus antigens were compared in a retrospective study with standard virus isolation procedures (VIP) for detection of alpha virus-infected mosquito pools. The original VIP was a plaque assay in chick embryo cell culture, and was performed in the years from 1979 to 1981. Using the original VIP as the reference standard, the sensitivity rate of the EIA was 0.7674 and the false negative rate was 0.2326. However, when the storage age and the initial virus titer of the sample were considered, the sensitivity ...
Montelaro RC, Parekh B, Orrego A, Issel CJ.The recurrent nature of equine infectious anemia has been attributed to relatively rapid antigenic variations in equine infectious anemia virus (EIAV) during persistent infection under selective immune pressures. This model was tested by serological and biochemical analysis of virus isolates recovered from separate febrile episodes in two experimentally infected ponies. Neutralization assays employing immune sera from the experimentally infected ponies demonstrated that distinct antigenic strains of virus predominate during sequential febrile episodes in a single pony. Analysis of the test str...
Payne S, Parekh B, Montelaro RC, Issel CJ.The unique periodic nature of equine infectious anaemia (EIA) is believed to result from the ability of the infecting virus. EIAV, to undergo relatively rapid antigenic variations which circumvent host immune responses resulting in distinct virus populations in sequential clinical episodes in the persistently infected horse. This model was examined by oligonucleotide mapping comparisons of the RNA genomes of selected isolates of EIAV. Variations in oligonucleotide maps could be reproducibly demonstrated (i) after adaptation of the laboratory strain of EIAV to replication in a pony, (ii) after ...
Montelaro RC, West M, Issel CJ.The immunogenic contributions of the carbohydrate and peptide portions of the major envelope glycoprotein of equine infections anemia virus, EIAV gp90, were analyzed by measuring the effects of specific glycosidase and protease digestions on the reactivity of the glycoprotein with immune sera from infected horses. The results of both direct and competitive radioimmunoassay demonstrated that immune sera contained antibodies reactive with both the carbohydrate and protein moieties of EIAV gp90, with the predominant reactivity apparently against the gp90 peptide epitopes. These results contrast w...
Timoney PJ, Geraghty VP, Harrington AM, Dillon PB.A microneutralization test in PK(15) cells was developed to measure the neutralizing antibody response of a group of ponies experimentally challenged with louping ill virus. Viral cytopathic effect was maximal after 6 days of incubation, at which point titration endpoints were clear-cut and readily determinable. The assay compared favorably with the mouse neutralization test for accuracy and ease of performance.
Bouillant AM, Becker SA.The successive steps of maturation of seven retroviruses from five species of farm animals and one retrovirus from a mouse were compared in cell cultures. The viruses included three type C oncoviruses, one spumavirus, and three lentiviruses. Although members of the 3 subfamilies shared some gross morphologic features such as budding on plasma membranes, core, and surface projections, differences were noted in the ultrastructural detail of these features. Type C oncoviruses did not show any structural differentiation in identifiable form in the cytoplasm as opposed to characteristic features ob...
Caughman GB, Staczek J, O'Callaghan DJ.Enveloped virions and nucleocapsids of equine cytomegalovirus (ECMV; equine herpesvirus type 2) have been purified from the supernatants and the nuclear extracts of infected rabbit kidney (RK) cells, respectively, and their structural protein compositions have been analyzed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that ECMV nucleocapsids were composed of nine proteins (average molecular weights = 148K, 52K, 49.5K, 46K, 43.5K, 38.5K, 27K, 20K, and 18K), which together constituted 89% of the total nucleocapsid protein on the basis of incorporated 3H-labeled am...
Yamagishi H, Ide S, Eiki T, Eiguchi Y, Nagamine T, Igarashi Y, Yoshioka I, Matumoto M.ESK cells, a stable cell line derived from a swine embryo kidney, were found to be a good medium for plaque formation of the Prague and Miami strains of equine influenza virus. Factors influencing the plaque formation were investigated and a plaque assay for these viruses was worked out. The method is not only simple enough for routine use, but also is as sensitive as the egg inoculation method. The method was readily adapted for a neutralization test.
Bean WJ.The RNAs coding for the nucleoproteins of a panel of influenza isolates from human and nonhuman hosts were compared by RNA-RNA hybridization to determine the extent of genetic diversity of this protein and to determine if related nucleoproteins (NP) are consistently found in viruses from certain hosts. Five nucleoprotein groups were defined. Group 1 contains nearly all of the avian influenza viruses, group 2 includes only certain viruses isolated from gulls, group 3 includes all recent equine influenza strains, group 4 contains only equine/Prague/1/56, and group 5 contains all human and swine ...
Gillespie J, Kalica A, Conner M, Schiff E, Barr M, Holmes D, Frey M.From 105 field cases of diarrhea in neonatal or young foals, rotavirus was detected by electron microscopy (EM) and/or by enzyme-linked immunosorbent assay (ELISA) in the feces of 65 foals on 16 different premises. ELISA was performed with Rotazyme test kits developed by Abbot and Company for the detection of rotaviruses. Twenty-four field isolates from the feces of diarrheic foals with equine rotavirus infection as ascertained by EM were placed in MA-104 cell cultures after pretreatment of the viral suspension with 10 micrograms ml-1 of trypsin and incorporation of 0.5 micrograms ml-1 or 1 mi...
Conner M, Kalica A, Kita J, Quick S, Schiff E, Joubert J, Gillespie J.Reoviruses have been isolated from a number of species including human, bovine, feline, canine and equine. In most species they seem to produce mild to inapparent disease. We have isolated a reovirus type 3 from a foal with diarrhea. The virus designated the Ralph strain has been propagated in both the MA-104 and A-72 cell lines. The strain produced cytoplasmic inclusion bodies in these cell cultures. Tissue-cultured virus fixed complement in the presence of reovirus antibodies, but failed to do so in the presence of rotavirus antiserum. By electron microscopy the viral particle measured +/- 6...
Staczek J, Wharton JH, Dauenhauer SA, O'Callaghan DJ.Semipermissive, primary hamster embryo (HE) cells were morphologically transformed in vitro by infection with UV-irradiated equine cytomegalovirus (equine herpesvirus type 2; ECMV). Cell lines (designated EC-1-3) were established independently from foci and were shown to exhibit growth and biological properties typically associated with transformed cells: altered morphology, loss of contact inhibition, increased saturation density, decreased generation time, immortality in culture, normal growth in low concentrations of serum, colony formation in soft agar, and resistance to ECMV superinfectio...
Mayr A, Thein P.At the moment, horse praxis is confronted by two disease complexes which are difficult to fight against as well in prophylaxis as in therapy, but which get an increasing importance. First they concern virus infections of the foals and second primary virus-caused respiratory diseases. Foals get infected during the embryonal/fetal development, in the perinatal or postnatal period. Normally the infection is caused by latent infected, clinical healthy mares, or in the postnatal period by ubiquitous, normally opportunistic socalled problem-viruses, i.e. equine herpes-viruses 1 and 2, rota-, corona-...
Gosztonyi G, Ludwig H.The brains of eight horses that had suffered from natural Borna disease were examined with virologic, immunohistological, and electron-microscopic methods. All brains harbored infectious virus as shown by inoculation of experimental animals. Regional assessment of the infectivity exhibited the highest titers in the hippocampus and piriform cortex and the lowest in the cerebellum. Conventional histology yielded pathologic alterations very similar to those of the classical description of the disease. Immunohistology demonstrated the highest amounts of Borna disease virus-specific antigen in the ...
Evans KS, Carpenter SL, Sevoian M.The enzyme-linked immunosorbent assay (ELISA) antigen-positive and agar-gel immunodiffusion test (AGID)-negative horses do not have infective equine infectious anemia (EIA) virus. The ELISA testing of horse leukocyte culture (HLC) supernatants did detect EIA virus in a HLC that was infected with the Wyoming strain of EIA virus and in HLC derived from horses in febrile, acute, or subacute stages of EIA infection. In supernatants of HLC derived from chronic and inapparent carrier horses, EIA virus was not detected with ELISA. Direct fluorescent antibody tests detected EIA virus in HLC infected w...
Rogers GN, Pritchett TJ, Lane JL, Paulson JC.Human and animal (avian and equine) influenza A virus isolates of the H3 serotype exhibit marked differences in their ability to bind specific sialyloligosaccharide sequences that serve as cell surface receptor determinants (G. Rogers and J. Paulson, 1983, Virology 127, 361-373). Whereas human isolates of this subtype strongly agglutinate enzymatically modified human erythrocytes containing the terminal SA alpha 2,6Gal sequence, avian and equine isolates preferentially agglutinate erythrocytes bearing the SA alpha 2, 3Gal sequence. As shown in this report, a glycoprotein found in horse serum, ...
Collins P.In vitro sensitivity data suggest that acyclovir should be effective against clinical manifestations of herpes simplex virus types 1 and 2, varicella-zoster virus and possibly Epstein-Barr virus. The clinical potential against herpes simplex virus types 1 and 2 is further supported by results in animal models. Human cytomegalovirus and the veterinary herpes viruses, with the possible exception of equine herpes virus type 1, may be insufficiently sensitive to be amenable to treatment.
Hoshino Y, Wyatt RG, Greenberg HB, Kalica AR, Flores J, Kapikian AZ.A rotavirus, designated as the H-1 strain, was isolated from a diarrheic foal in primary African green monkey kidney cells and MA104 cells. This cell culture-adapted strain hemagglutinated erythrocytes of human group O, rhesus monkeys, guinea pigs, and sheep. It was found to be similar, if not identical, to porcine rotaviruses (strains OSU, EE, and A-580) by plaque reduction neutralization and hemagglutination inhibition tests, and, in addition, it was found to belong to subgroup 1. This equine rotavirus has an RNA electrophoretic migration pattern which was distinct from those of the three st...
Rebollo B, Sarraseca J, Lecollinet S, Abouchoaib N, Alonso J, García-Bocanegra I, Sanz AJ, Venteo Á, Jiménez-Clavero MA.West Nile virus (WNV) is a zoonotic arboviral pathogen affecting humans, birds, and horses. Vaccines are available for veterinary use, which efficiently prevent the infection in horses. Most common diagnostic tools rely on the identification of the agent (RT-PCR, virus isolation), or on the detection of antibodies (IgM and IgG) recognizing structural proteins of the virus or neutralizing virus infection in cell cultures (virus-neutralization tests). The recent emergence of WNV in different parts of the world has resulted in an increase in the vaccination of horses in many countries. Methods fo...
Mizukoshi N, Sakamoto K, Iwata A, Ueda S, Kamada M, Fukusho A.The reverse transcription followed by the polymerase chain reaction (RT-PCR) technique was applied to the detection of African horsesickness virus (AHSV) using primers specific for attenuated AHSV serotype 4 segment 5 (NS1 gene). Total RNA which contains both messenger RNA and genomic dsRNA was extracted by the acid guanidinium-phenol-chloroform method from the AHSV infected Vero cells and was used as templates to optimize the RT-PCR. A pair of primer (NP2-NP32) amplified the product of the expected size from all serotypes of attenuated AHSV when four pairs of primers were tested. Using this p...
Baker EF, Sasso DR, Maness K, Prichard WD, Parker RL.In 1971, more than 370 horses in south Texas were studied with respect to their clinical, virologic, and neutralizing antibody responses to vaccination with Venezuelan equine encephalomyelitis (VEE) strain TC-83. This study confirms reported findings that the vaccine used in the 1971 epizootic in the lower Rio Grande Valley of Texas was safe and efficacious. Vaccinal virus viremia titers were generally below the postulated infection threshold of epizootic vectors. In general, reactions to the vaccine were minimal and transient, with no observed abortions or deaths attributable to use of the va...
The goal of this work was the development of suitable (real-time) RT-PCR techniques for fast and sensitive diagnosis of EAV and for molecular-epidemiological characterisation of viral strains, as an alternative to virus isolation. To this purpose two conventional RT-PCR methods and one real-time RT-PCR were adapted to detect the broadest possible spectrum of viral strains. Several dilutions with Bucyrus strain showed a 100-fold higher sensitivity of real-time RT-PCR and heminested RT-PCR compared to simple RT-PCR. Making use of 11 cell culture supernatants of different EAV isolates and 7 semen...
Sullivan E, Lecollinet S, Kerviel A, Hue E, Pronost S, Beck C, Dumarest M, Zientara S, Roy P.African horse sickness virus (AHSV) is an Orbivirus within the Reoviridae family, spread by Culicoides species of midges, which infects equids with high mortality, particularly in horses and has a considerable impact on the equine industry. In order to control the disease, we previously described Entry Competent Replication Abortive (ECRA) virus strains for each of the nine distinct AHSV serotypes and demonstrated their potential as vaccines, first in type I interferon receptor (IFNAR-/-) knockout mice, and then in ponies. In this report we have investigated whether or not a combination ECRA v...
Kirisawa R, Hosoi Y, Yamaya R, Taniyama H, Okamoto M, Tsunoda N, Hagiwara K, Iwai H.We isolated a variant equine herpesvirus-1 (EHV-1), strain 5089, from the lung of a dead neonatal foal in Japan and characterized the biological nature of the virus. The virus spread in cultured cells mainly by cell-to-cell infection, unlike wild-type EHV-1, which spreads efficiently as a cell-free virus. The virus titer in cultured supernatant and the intracellular virus titer were low compared to those of wild-type EHV-1. Heparin treatment of the virus had no effect on viral infectivity in cell culture. Glycoprotein C (gC) was not detected by Western blotting and fluorescent antibody tests i...
Mittelholzer C, Johansson I, Olsson AK, Ronéus M, Klingeborn B, Belák S.Recovery of infectious Equine arteritis virus (EAV) from the semen of persistently infected Swedish stallions was attempted by classical cell culture isolation and by transfection of extracted total RNA. Whereas virus from semen samples stored for several months at -20 degrees C or from extended semen could only be recovered by transfection of extracted RNA, isolation in cell culture was achieved readily with fresh, unextended semen stored at -70 degrees C or directly used after sampling. In parallel, the viruses were examined in the variable region of the large glycoprotein GP5 by nested RT-P...
Spyrou V, Papanastassopoulou M, Psychas V, Billinis Ch, Koumbati M, Vlemmas J, Koptopoulos G.There appears to be a lack of information concerning responses of mules to natural infection or experimental inoculation with equine infectious anemia virus (EIAV). In the present study EIAV was isolated from mules, for the first time, and its pathogenicity in naturally infected and experimentally inoculated animals was investigated. Two naturally infected (A and B) and three EIAV free mules (C, D and E) were used for this purpose. Mule A developed clinical signs, whereas mule B remained asymptomatic until the end of the study. Mules C and D were each inoculated with 10ml of blood from mule A ...
Oxburgh L, Berg M, Klingeborn B, Emmoth E, Linné T.The antigenic properties of H3N8 equine influenza virus from the Swedish epizootic of 1991 differ from those of A/eq 2/Fontainebleau/79 (representative of the Swedish vaccine strain) in hemagglutination inhibition tests. The amino acid sequence of the hemagglutinin (HA) of an isolate from the 1991 outbreak was deduced from the nucleotide sequence and comparison was made to the A/eq 2/Fontainebleau/79 strain. Twenty-three amino acid substitutions were found, 10 mapping onto areas of the HA known to bind antibodies in human H3 influenza viruses. The amino acid changes together with the serologic...
Morier L, Cantelar N, Soler M.Eastern Equine Encephalitis (EEE) was in Cuba before the 1940s; the virus has been isolated from horses, birds, and rodents during epizootic as well as interepizootic periods. The only isolation of Western Equine Encephalitis (WEE) virus was from a sick pigeon found in the vicinity of Havana University. Both viruses can cause human disease; the isolation of WEE virus from the centre of an urban area emphasises the need for the prompt isolation and rapid identification of these agents. The object of this work was to compare the sensitivity of a continuous cell line (XL-2) from the toad, Xenopus...
Birch-Machin I, Ryder S, Taylor L, Iniguez P, Marault M, Ceglie L, Zientara S, Cruciere C, Cancellotti F, Koptopoulos G, Mumford J, Binns M....Three filamentous phage random peptide display libraries were used in biopanning experiments with purified IgG from the serum of a gnotobiotic foal infected with equine herpesvirus-1 (EHV-1) to enrich for epitopes binding to anti-EHV-1 antibodies. The sequences of the amino acids displayed were aligned with protein sequences of EHV-1, thereby identifying a number of potential antibody binding regions. Presumptive epitopes were identified within the proteins encoded by genes 7 (DNA helicase/primase complex protein), 11 (tegument protein), 16 (glycoprotein C), 41 (integral membrane protein), 70 ...
Paweska JT, Gerdes T, Van Heerden J.Rabbit hyperimmune serum prepared against a donkey alphaherpesvirus isolate (M7/91), and against EHV-1 and EHV-4 was used to characterise the antigenic relationship between these 3 viruses. Serum from immunised rabbits was always more specific for homologous virus and showed different cross reactivity for heterologous virus. It was concluded that the immunologic relationship between the M7/91 isolate and EHV-1, was closer than that between this isolate and EHV-4. A serological survey of donkeys (n = 116) and horses (n = 57) revealed evidence of the presence of neutralising antibody to M7/91 in...
O'Niell FD, Issel CJ.Growth kinetics of equine influenza virus-A1, equine herpesvirus-1, and equine rhinovirus-1 were determined in susceptible cell monolayers and in organ cultures of equine fetal tracheal and nasal turbinate epithelium. Equine influenza virus-A1 was replicated in cell and organ cultures and was released more readily and for longer periods from nasal turbinate epithelium than from tracheal epithelium. Equine herpesvirus-1 was also replicated in cell and organ cultures. During the first 24 hours after inoculation, equine herpesvirus-1 was released more readily from tracheal epithelium than from na...
Lee HS, Heo EJ, Jeoung HY, Ko HR, Kweon CH, Youn HJ, Ko YJ.In this study, an enzyme-linked immunosorbent assay (ELISA) using glycoprotein and a monoclonal antibody (MAb) was developed for the detection of antibodies to vesicular stomatitis virus (VSV) serotype New Jersey (NJ). The glycoprotein to be used as a diagnostic antigen was extracted from partially purified VSV-NJ, and a neutralizing MAb specific to VSV-NJ was incorporated to compete with antibodies in a blocking ELISA using glycoprotein (GP ELISA). The cutoff of the GP ELISA was set at 40% inhibition, which corresponded to a virus neutralization test (VNT) titer of 32. With this threshold, th...
Faber E, Tshilwane SI, Van Kleef M, Pretorius A.Expanding on our previous work, this study used transcriptome analysis of RNA sequences to investigate the various factors that contributed to either inducing apoptosis that resulted in cell death or promoting the survival of African horse sickness virus serotype 4 (AHSV4)-infected horse peripheral blood mononuclear cells (PBMC) after 24 h. Apoptosis is a host defense mechanism that prevents virus replication, accumulation and spread of progeny viruses. AHSV4-infected PBMC were killed via the intrinsic and the perforin/granzyme pathways of apoptosis during the attenuated AHSV4 (attAHSV4) in v...
Matczuk AK, Chodaczek G, Ugorski M.Equine arteritis virus (EAV) is a prototype member of the Arterivirus family, comprising important pathogens of domestic animals. Minor glycoproteins of Arteriviruses are responsible for virus entry and cellular tropism. The experimental methods for studying minor Arterivirus proteins are limited because of the lack of antibodies and nested open reading frames (ORFs). In this study, we generated recombinant EAV with separated ORFs 3 and 4, and Gp3 carrying HA-tag (Gp3-HA). The recombinant viruses were stable on passaging and replicated in titers similar to the wild-type EAV. Gp3-HA was incorpo...
Justines G, Oro G, Alvarez O.The P-676 and MF-8 epizootic strains of Venezuelan equine encephalitis (VEE) virus were found to contain a minute plaque (MP), different from the predominant small plaque (SP) present in these virus strains. The MP and SP were stable after passages in Vero cells, mice, or horses. Equines were inoculated with the SP or MP of the P-676 and MF-8 strains. Inoculation of either P-676 SP or MP into horses induced high fever and viremia but no signs of encephalitis or death. Four horses infected with MF-8 SP became very ill, with high fever and viremia; three of the inoculated animals died. Four hors...
Lu G, Huang J, Li S.Theiler's disease-associated virus (TDAV) could be the aetiological agent of Theiler's disease. Horses experimentally inoculated with equine plasma containing TDAV develop acute and chronic infections with viraemia. Since its first identification in 2013, TDAV has not been detected in equines in the epidemiological studies that have been conducted. Until now, only one genome sequence of TDAV (HorseA1_serum) had been obtained. In this study, we sequenced the genome of four TDAV strains (A/China, F/China, H/USA and I/USA) in commercial equine sera used for cell culture propagation in China using...
Fukunaga Y, Wada R, Imagawa H, Kanemaru T.Venereal infection with equine arteritis virus (EAV) was established in each of seven mares by inoculation via the cervix with 20 ml of viral suspension (> or = 8 x 10(6) plaque-forming units; PFU), following treatment with prostaglandin and oestradiol. A dose of < or = 8 x 10(5) PFU produced infection in only five of eight mares. Serum neutralizing antibody developed in mares manifesting clinical signs of equine viral arteritis (EVA), and a weak antibody was detectable in one apparently healthy mare inoculated with 8 x 10(5) PFU. Virus isolation was demonstrated not only in the buffy coat but...
Stasiak K, Rola J, Zmudzinski JF.A highly sensitive and specific real-time PCR assay was used for detection and quantitation of equine herpesvirus type 1 (EHV-1) in the different internal organs of aborted fetuses. Tissue samples from 23 aborted fetuses submitted to the Department of Virology of the National Veterinary Research Institute in Pulawy between 2012 and 2013 were used for testing. Total DNA was extracted using a phenol-chloroform-isoamyl alcohol standard protocol. A real-time PCR with forward and reverse primers encompassing a highly conserved region encoding viral glycoprotein B was adapted for diagnosis of EHV-1 ...
Chambers TM, Reedy SE.In horses, presumptive diagnosis of equine influenza is commonly made on the basis of clinical signs. This alone is insufficient for confirmation of equine influenza, because other equine infectious respiratory diseases can in some degree have similar clinical presentations. Surveillance and control of equine influenza also necessitate detection of subclinical cases. Effective diagnosis of equine influenza virus infection is critically dependent on obtaining adequate specimens of virus-containing respiratory secretions for testing. These specimens are also valuable as sources for isolation of ...
Weerasinghe CU, Learmonth GS, Gilkerson JR, Foote CE, Wellington JE, Whalley JM.The envelope glycoprotein D of EHV-1 (EHV-1 gD) is essential for virus infectivity and entry of virus into cells and is a potent inducer of virus-neutralizing antibody. In this study, truncated EHV-1 gD (gDt) was expressed with a C-terminal hexahistidine tag in E. coli using a pET vector. Western blot analysis using an anti-gD monoclonal antibody demonstrated the presence of gDt bands at 37.5, 36, 29.5 and 28 kDa. The immunogenicity and protective efficacy of partially purified gDt was compared with gD expressed in insect cells by a recombinant baculovirus (Bac gD) using a BALB/c mouse model o...
Han X, Zhang P, Yu W, Xiang W, Li X.The Chinese EIAV vaccine is an attenuated live virus vaccine obtained by serial passage of a virulent horse isolate (EIAV) in donkeys (EIAV) and, subsequently, in donkey cells in vitro. In this study, we compare the env gene of the original horse virulent virus (EIAV) with attenuated strains serially passaged in donkey MDM (EIAV) and donkey dermal cells (EIAV). Genetic comparisons among parental and attenuated strains found that vaccine strains contained amino acid substitutions/deletions in gp90 that resulted in a loss of three potential N-linked glycosylation sites, designated g5, g9, and g1...
Scott GR.Twelve DNA viruses and forty‐three RNA viruses are known to infect horses. In addition, there are three unclassified viruses and, at least, three alleged viruses infecting horses. Differential diagnosis is difficult. At least twenty‐eight of the fifty‐eight viruses induce clinical disease but the range of syndromes is limited; eleven provoke respiratory symptoms and eleven cause encephalitis. Thirty‐four equine viruses with a limited geographical distribution are transmitted by arthropod vectors. Twenty viruses are spread by contact and their distribution, in general, is global. The ve...
Ellenberger C, Schüppel KF, Möhring M, Reischauer A, Alex M, Czerny CP, Fercho A, Schoon HA.Cowpox virus infection associated with a streptococcal septicaemia was diagnosed in a weak German Warmblood filly, born 29 days prematurely, and humanely destroyed on the sixth day of life. At necropsy, ulcerative lesions in the alimentary tract, colitis, polyarthritis and nephritis were observed. Transmission electron microscopical examination of specimens from ulcerative lesions revealed typical orthopox virions. Cowpox virus was unequivocally identified by virological and molecular-biological methods.
Yamanaka T, Tsujimura K, Kondo T, Matsumura T.To investigate the possibilities of two NA inhibitors [oseltamivir carboxylate (OC) and zanamivir (ZA)] as the clinical agents for equine influenza A virus (EIV) infection, we examined the efficacies of these inhibitors against twelve EIVs in vitro. OC and ZA inhibited NA activities of all EIVs with 50% inhibitory concentrations with ranging from 0.017 to 0.130 and from 0.010 to 0.074 microM, respectively. OC and ZA inhibited plaque-forming of all EIVs in MDCK cells with 50% effective concentrations with ranging from 0.015 to 0.097 and from 0.016 to 0.089 microM, respectively, except for one s...
Siedek EM, Whelan M, Edington N, Hamblin A.Equine herpesvirus type 1 (EHV-1) causes respiratory disease, abortion and myeloencephalopathy in horses. As with other herpesviruses, cell-mediated immunity is considered important for both recovery and protection. Although virus-specific T-cell proliferation and cytotoxicity can be detected following in vivo infection, little is known about the role of antigen presenting cells such as dendritic cells (DCs) in these processes. Peripheral blood DCs were shown to express the viral glycoprotein gB perinuclearly following exposure to EHV-1 in vitro, demonstrating EHV-1 replication within them. Co...
Anderson C, Baha H, Boghdeh N, Barrera M, Alem F, Narayanan A.Zoonotic pathogens that are vector-transmitted have and continue to contribute to several emerging infections globally. In recent years, spillover events of such zoonotic pathogens have increased in frequency as a result of direct contact with livestock, wildlife, and urbanization, forcing animals from their natural habitats. Equines serve as reservoir hosts for vector-transmitted zoonotic viruses that are also capable of infecting humans and causing disease. From a One Health perspective, equine viruses, therefore, pose major concerns for periodic outbreaks globally. Several equine viruses ha...
Tortschanoff M, Aurich C, Rosengarten R, Spergser J.Mycoplasma equigenitalium and Mycoplasma subdolum have been associated with infertility, endometritis, vulvitis and abortions in mares, and with reduced fertility and balanoposthitis in stallions. Despite their role in equine genital disorder, determinants of virulence and pathogenesis as well as factors provoking specific host immune responses have not been identified, so far. To establish the major immunogenic components of Mycoplasma (M.) equigenitalium and M. subdolum, antigen profiles of their type strains as well as 30 clinical isolates were compared by SDS-PAGE and immunoblot analysis u...
Han X, Zou J, Wang X, Guo W, Huo G, Shen R, Xiang W.The Chinese EIAV vaccine is an attenuated live-virus vaccine obtained by serial passage of a virulent horse isolate (EIAV(L)) in donkeys (EIAV(D)), and subsequently in donkey cells in vitro. In this study, we compare the env gene of the original horse virulent virus (EIAV(L)) with attenuated strains serially passaged in donkey MDM (EIAV(DLV)), and donkey dermal cells (EIAV(FDDV)). Genetic comparisons among parental and attenuated strains found that vaccine strains contained amino acid substitutions/deletions in gp90 that resulted in a loss of three potential N-linked glycosylation sites, desig...
