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.
Siger L, Bowen RA, Karaca K, Murray MJ, Gordy PW, Loosmore SM, Audonnet JC, Nordgren RM, Minke JM.To determine the onset of immunity after IM administration of a single dose of a recombinant canarypox virus vaccine against West Nile virus (WNV) in horses in a blind challenge trial. Methods: 20 mixed-breed horses. Methods: Horses with no prior exposure to WNV were randomly assigned to 1 of 2 groups (10 horses/group). In 1 group, a recombinant canarypox virus vaccine against WNV was administered to each horse once (day 0). The other 10 control horses were untreated. On day 26, 9 treated and 10 control horses were challenged via the bites of mosquitoes (Aedes albopictus) infected with WNV. Cl...
Zevenhoven-Dobbe JC, Greve S, van Tol H, Spaan WJM, Snijder EJ.Equine arteritis virus (EAV) contains seven structural proteins that are all required to produce infectious progeny. Alphavirus-based expression vectors have been generated for each of these proteins to explore the possibilities for their constitutive expression in cell lines. This approach was successful for minor glycoproteins GP(2b), GP(3) and GP(4) and for the E protein. Subsequently, it was demonstrated that cell lines expressing these proteins could rescue EAV mutants that were disabled in the expression of the corresponding gene, resulting in the production of virus particles carrying t...
Ibrahim el SM, Pagmajav O, Yamaguchi T, Matsumura T, Fukushi H.Nucleotide sequences of the intergenic region between ORF 62 and ORF 63 of equine herpesvirus 1 (EHV-1) isolates were analyzed. The sequences of this region consisted of variable and conserved domains among EHV-1 isolates. An EHV-1 mutant, Ab4-GFP, was constructed by inserting a green fluorescent protein (GFP) expression cassette flanked by lox P at both ends into the intergenic region between ORF 62 and ORF 63. Another mutant, Ab4-loxP, which contains one lox P site, was constructed by excision of the GFP cassette from the Ab4-GFP virus genome by cre enzyme. The recombinant Ab4-GFP formed sma...
Jin S, Issel CJ, Montelaro RC.We recently reported a highly protective attenuated live virus vaccine for equine infectious anemia virus (EIAV) based on a proviral construct (EIAVUKDeltaS2) with a genetically engineered mutation in the viral S2 gene that eliminates expression of this accessory protein. While the EIAVUKDeltaS2 vaccine provides protection from detectable infection by experimental challenge with highly virulent virus, the potential for commercial application of this vaccine is complicated by the fact that horses inoculated with the EIAVUKDeltaS2 vaccine strain become seropositive in various reference diagnosti...
Konishi E, Shoda M, Ajiro N, Kondo T.Antibodies to Japanese encephalitis virus (JEV) nonstructural 1 (NS1) protein constitute a marker of natural JEV infection among populations vaccinated with inactivated JE vaccine. In Japan, with few recent human JE cases, the natural infection rate is critical to evaluate the necessity of continuing JE vaccination. A sensitive immunochemical staining method for detecting NS1 antibodies in individuals naturally and subclinically infected with JEV was previously established. Here, an enzyme-linked immunosorbent assay (ELISA) to detect NS1 antibodies in equine sera was developed and evaluated as...
Reed SM, Toribio RE.Equine herpesvirus infections in horses remain a significant cause of abortion and neurologic disease. These viruses are also responsible for mild signs of respiratory disease. The ability to establish latent infections with periodic reactivation or transmission to other horses is an important feature of these herpesviruses. One of the most unique aspects of this report is the description of horses demonstrating neurologic signs serving as the source of infection for other horses. Accurate diagnosis and better means of protection for horses remain problems facing veterinarians and horse owners...
Balasuriya UB, MacLachlan NJ.The members of the family Arteriviridae, genus Arterivirus, include equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), lactate dehydrogenase-elevating virus (LDV) of mice, and simian hemorrhagic fever virus (SHFV). PRRSV is the newest member of the family (first isolated in North America and Europe in the early 1990s), whereas the other three viruses were recognized earlier (EAV in 1953, LDV in 1960, and SHFV in 1964). Although arterivirus infections are strictly species-specific, the causative agents share many biological and molecular properties, inclu...
Koekemoer JJ, Dijk AA.Since protection against African horsesickness (AHS) is serotype-specific, rapid serotyping of AHSV is crucial to identify the correct vaccine serotype for efficient control of the spread of AHS outbreaks, especially when they occur in non-endemic regions. This paper describes the first one-day serotyping procedure that requires only a single RT-PCR and hybridization and which can identify multiple serotypes in mixed infections in one assay. The same region of genome segment 2 of all nine AHSV serotypes is amplified in a single RT-PCR. A universal primer set, designed to amplify the 5'-termina...
Ghim SJ, Rector A, Delius H, Sundberg JP, Jenson AB, Van Ranst M.Equus caballus papillomavirus type 1 (EcPV-1) was isolated from a cutaneous papilloma, the most common neoplasm in horses. The complete EcPV-1 nucleotide sequence and genomic organization were determined. Phylogenetic analysis showed that EcPV-1 is a close-to-root papillomavirus, with only distant relationships to the fibropapillomaviruses and the benign cutaneous papillomaviruses. To produce EcPV-1 virus-like particles (VLPs), the EcPV-1 L1 major capsid protein was expressed in insect cells using a recombinant baculovirus vector. The self-assembled EcPV-1 VLPs were morphologically indistingui...
Singh BK, Ahuja S, Gulati BR.A single-dilution, sensitive and specific monoclonal antibody-based blocking enzyme-linked immunosorbent assay (B-ELISA) was developed as an alternative to the cumbersome virus neutralization test (VNT) for detection of equine herpesvirus-1 (EHV-1) antibodies. Neutralizing monoclonal antibodies (1H6 and 9C6) raised against EHV-1 (Hisar-90-7 strain) and sera from 70 horses (30 known negative and 40 known positive for EHV-1 antibodies by VNT) were used for standardization of the B-ELISA. Using a single serum dilution of 1:250 in B-ELISA, 100% specificity was obtained with both monoclonal antibod...
Shirato K, Kimura T, Mizutani T, Kariwa H, Takashima I.West Nile (WN) virus is a mosquito-borne flavivirus that can cause lethal encephalitis in humans and horses. The WN virus endemic in New York City (NY) in 1999 caused large-scale mortality of wild birds that was not evident in endemic areas in other parts of the world, and the pathogenesis of the WN virus strain isolated in NY (NY strain) appears to differ from that of previously isolated strains. However, the pathogenesis of NY strain infection remains unclear. This study examined CC (RANTES/CCL5, MIP-1 alpha/CCL3, MIP-1 beta/CCL4) and CXC (IP-10/CXCL10, B lymphocyte chemoattractant (BLC/CXCL...
Martinez I, Barrera JC, Rodriguez LL, Wertz GW.Vesicular stomatitis virus (VSV) is the most common cause of vesicular disease outbreaks in livestock throughout the Western Hemisphere. Two major serotypes, Indiana and New Jersey, cause epidemic disease in pigs, cattle, and horses. We generated recombinant viruses derived from the Indiana serotype genome that were engineered to contain and express: (1) a single copy of the glycoprotein gene from the Indiana serotype (VSIV-GI); (2) a single copy of the glycoprotein gene from the New Jersey serotype (VSIV-GNJ); or (3) two copies of the glycoprotein gene, one from each of the two major VSV sero...
Newton JR, Geraghty RJ, Castillo-Olivares J, Cardwell JM, Mumford JA.Several laboratories worldwide have recently experienced problems related to serum cytotoxicity with the equine arteritis virus (EAV) neutralisation test (VN) when using Office International des Epizooties (OIE) reference laboratory prescribed rabbit kidney (RK-13) indicator cells. Cytotoxicity can be mistaken for viral cytopathic effect and has led to increasing difficulties in test interpretation, consequently causing disruption to both equine breeding and disease surveillance. Results from experimental and field-derived data suggest that this serum cytotoxicity is associated with use of a t...
Rosati S, Profiti M, Lorenzetti R, Bandecchi P, Mannelli A, Ortoffi M, Tolari F, Ciabatti IM.Among animal lentiviruses, Feline immunodeficiency virus (FIV), Equine infectious anaemia virus (EIAV) and Small ruminant lentiviruses (SRLV) are important pathogens associated with a variety of clinical pictures including immunodeficiency, anaemia, arthritis, pneumonia. The detection of viral antibody response represents a practical diagnostic approach in all lentivirus infections since they remain detectable long life. Capsid antigen (CA) is the major viral core protein and specific antibodies against this antigen are usually first recognised in infected sheep, goat and horse, remaining dete...
Oaks JL, Long MT, Baszler TV.Neurologic disease occurs sporadically in horses infected with the equine infectious anemia virus (EIAV). This report describes a case of clinically severe neurologic disease in a pony experimentally infected with EIAV. This pony did not have fever or anemia, which are the characteristic clinical signs of disease. The histopathologic changes were characterized as lymphohistiocytic periventricular leukoencephalitis. Polymerase chain reaction and in situ hybridization data showed that the brain lesions were directly associated with viral replication and that high-level viral replication occurred...
Chung C, Mealey RH, McGuire TC.Cytotoxic T lymphocytes (CTL) are important for controlling equine infectious anemia virus (EIAV). Because Gag matrix (MA) and capsid (CA) are the most frequently recognized proteins, the hypothesis that CTL from EIAV-infected horses with diverse MHC class I alleles recognize epitope clusters (EC) in these proteins was tested. Four EC were identified by CTL from 15 horses and 8 of these horses had diverse MHC class I alleles. Two of the eight had CTL to EC1, six to EC2, five to EC3, and four to EC4. Because EC2-4 were recognized by CTL from >50% of horses with diverse alleles, the hypothesi...
Blitvich BJ, Fernández-Salas I, Contreras-Cordero JF, Loroño-Pino MA, Marlenee NL, Díaz FJ, González-Rojas JI, Obregón-Martínez N....West Nile virus RNA was detected in brain tissue from a horse that died in June 2003 in Nuevo Leon State, Mexico. Nucleotide sequencing and phylogenetic analysis of the premembrane and envelope genes showed that the virus was most closely related to West Nile virus isolates collected in Texas in 2002.
Mealey RH, Leib SR, Pownder SL, McGuire TC.Equine infectious anemia virus (EIAV) is a lentivirus that causes persistent infection in horses. The appearance of antigenically distinct viral variants during recurrent viremic episodes is thought to be due to adaptive immune selection pressure. To test this hypothesis, we evaluated envelope SU cloned sequences from five severe combined immunodeficient (SCID) foals infected with EIAV. Within the SU hypervariable V3 region, 8.5% of the clones had amino acid changes, and 6.4% had amino acid changes within the known cytotoxic T lymphocyte (CTL) epitope Env-RW12. Of all the SU clones, only 3.1% ...
Hall RA, Khromykh AA.West Nile virus (WNV) is a mosquito-borne flavivirus that is emerging as a global pathogen. In the last decade, virulent strains of the virus have been associated with significant outbreaks of human and animal disease in Europe, the Middle East and North America. Efforts to develop human and veterinary vaccines have taken both traditional and novel approaches. A formalin-inactivated whole virus vaccine has been approved for use in horses. DNA vaccines coding for the structural WNV proteins have also been assessed for veterinary use and have been found to be protective in mice, horses and birds...
Patel JR, Didlick S, Bateman H.Currently, there is no recommended immunoprophylaxis against febrile respiratory diseases due to equine herpesvirus-1 (EHV-1) and -4 (EHV-4) in horses below age 5-6 months. This is because of interference by maternally-derived antibody (MDA) of vaccines. Objective: Unweaned equine foals are an important reservoir of EHV-1 transmission; therefore, we experimentally assessed the efficacy of a live EHV-1 vaccine in foals age 1.4-3.5 months with MDA. Methods: Following vaccination and challenge, parameters assessed were virus shedding in nasal mucus, leucocyte-associated viraemia, circulating viru...
Minke JM, Audonnet JC, Fischer L.The increasing international movement of horses combined with the relaxation of veterinary regulations has resulted in an increased incidence of equine infectious diseases. Vaccination, along with management measures, has become the primary method for the effective control of these diseases. Traditionally modified live and inactivated vaccines have been used and these vaccines have proven to be very successful in preventing disease. However, there are a number of equine infectious diseases for which conventional technology has shown its limitations. The advent of recombinant technology has sti...
Leroux C, Cadoré JL, Montelaro RC.Equine Infectious Anemia Virus (EIAV) is a lentivirus, of the Retrovirus family, with an almost worldwide distribution, infecting equids. It causes a persistent infection characterized by recurring febrile episodes associating viremia, fever, thrombocytopenia, and wasting symptoms. The disease is experimentally reproducible by inoculation of Shetland ponies or horses with EIAV pathogenic strains. Among lentiviruses, EIAV is unique in that, despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever ...
Dai CM, Zhang XY, Zhang RR, Shao YM, Shen RX.To develop a novel vaccine candidate of Equine infectious anemia virus(EIAV). Methods: env genes of EIAV Chinese donkey leukocyte attenuated strain (EIAV DLV) and its parental virus strain (EIAV LN) were expressed using the BAC-To-BAC system, and Env proteins were confirmed by SDS-PAGE and Western blot. BALB/c mice were immunized with recombinant vaccinia viruses containing env genes of EIAV alone or boosted with Env proteins expressed by recombinant baculovirus. Both protective humoral and cellular immune responses were detected. Results: Recombinant baculovirus could express complete Env pro...
Tewari D, Kim H, Feria W, Russo B, Acland H.West Nile virus (WNV) RNA was quantified in WNV infected crows and horses with the help of a real-time reverse transcriptase-PCR assay. A 5' nuclease assay, based on NS5 gene detection with a fluorescent probe was used for quantifying WNV RNA using formalin fixed paraffin embedded tissue specimens. Quantitative detection of WNV RNA showed the presence of a higher amount of the viral RNA in crow tissues compared to equine tissues and these results correlated well with the detection of WNV antigen by immunostaining. In crows, the highest amount of virus was seen in the intestine and in horses in...
Oleksiewicz MB, Snijder EJ, Normann P.A putative zinc finger (ZF) domain in the Equine arteritis virus (EAV) nsp1 protein was described recently to be required for viral transcription. The nsp1 ZF (50 aa) was expressed on the surface of M13KE gIII phage, fused to the N terminus of the phage pIII protein. To evaluate the functionality of the ZF domain, a binding assay was developed, based on the use of immobilized Ni(2+) ions (Ni-NTA). Phages displaying ZF bound significantly better to Ni-NTA than did phages displaying negative-control peptides, which also contained metal-coordinating residues. Also, binding of ZF-displaying phages...
Genzel Y, Behrendt I, König S, Sann H, Reichl U.The production of equine influenza in Madin-Darby canine kidney (MDCK) cells in large-scale microcarrier culture is described with detailed on- and off-line analytical data during cell growth and virus replication. Metabolite concentration profiles for glucose, glutamine, lactate and ammonium are shown. Lactate and ammonium concentrations were always below inhibiting levels. Concentration profiles for essential and non-essential amino acids of the cell culture medium are discussed. During cell growth proline was released into the medium with a significant rate while two amino acids, serine and...
Minke JM, Siger L, Karaca K, Austgen L, Gordy P, Bowen R, Renshaw RW, Loosmore S, Audonnet JC, Nordgren B.An ALVAC (canarypoxvirus)-based recombinant (vCP2017) expressing the prM and E genes derived from a 1999 New York isolate of West Nile virus (WNV) was constructed and assessed for its protective efficacy in horses in two different experiments. In the first trial, a dose titration study was conducted to evaluate both serum neutralising antibody responses to WNV and duration of immunity. In the second trial the onset of protection was determined. Twenty-eight adult horses received two doses of vCP2017 administered intramuscularly at 5-week intervals and sixteen horses comprised age-matched non-v...
Studdert MJ, Azuolas JK, Vasey JR, Hall RA, Ficorilli N, Huang JA.To develop and validate specific, sensitive and rapid diagnostic tests using RT-PCR for the detection of Ross River virus (RRV), Kunjin virus (KV) and Murray Valley encephalitis virus (MVEV) infections in horses. Methods: Primer sets based on nucleotide sequence encoding the envelope glycoprotein E2 of RRV and on the nonstructural protein 5 (NS5) of KV and MVEV were designed and used in single round PCRs to test for the respective viruses in infected cell cultures and, in the case of RRV, in samples of horse blood and synovial fluid. Results: The primer pairs designed for each of the three vir...
Azuolas JK, Wishart E, Bibby S, Ainsworth C.To report clinical and clinicopathological findings in horses naturally infected with Ross River virus (RRV) and identify likely mosquito arbovirus vector species. Methods: Veterinarians submitted serum samples from 750 horses because they suspected Ross River virus (RRV) infection. The samples were tested for the presence of IgM and IgG antibody to RRV and for the presence of virus. Mosquitoes were trapped, differentiated to species level and tested for the presence of RRV by virus isolation. Results: RRV was isolated from six species of mosquitoes (Ochlerotatus camptorhyncus, Culex globocoxi...
Balasuriya UB, Dobbe JC, Heidner HW, Smalley VL, Navarrette A, Snijder EJ, MacLachlan NJ.We have used an infectious cDNA clone of equine arteritis virus (EAV) and reverse genetics technology to further characterize the neutralization determinants in the GP5 envelope glycoprotein of the virus. We generated a panel of 20 recombinant viruses, including 10 chimeric viruses that each contained the ORF5 (which encodes GP5) of different laboratory, field, and vaccine strains of EAV, a chimeric virus containing the N-terminal ectodomain of GP5 of a European strain of porcine reproductive and respiratory syndrome virus, and 9 mutant viruses with site-specific substitutions in their GP5 pro...
Sun Y, MacLean AR, Aitken JD, Brown SM.Equine herpesvirus type 1 (EHV-1) gene 71 encodes a heavily O-glycosylated 192 kDa protein with no identified herpesvirus homologue. Isolation of a deletion mutant in gene 71 (ED71) demonstrated that its protein product is not essential in vitro. To investigate the role of the gene 71 protein in the virus life cycle, ED71 has been characterized in vitro in terms of cellular adsorption, penetration, egress and transmission compared to wild-type and revertant virus. ED71 virions adsorbed to cells less efficiently than wild-type and revertant virus with a consequential effect on virus penetration...
McCartan CG, Russell MM, Wood JL, Mumford JA.An outbreak of equine herpesvirus-1 (EHV-1) occurred on a large stud farm with 133 mares, 54 foals and four stallions, and at least 85 mares, 22 foals and three stallions were infected. Clinical disease was observed in 16 mares, two stallions and 13 foals and the predominant clinical signs were scrotal oedema, ataxia and loss of libido in the stallions, ataxia and recumbency in the mares and uveitis and nasal discharge in the foals, although pneumonia and colic with intussusception were also recorded at autopsy. Neurological disease was more common in the mares nursing foals (12 of 38 infected...
Current HIV researchMarch 10, 2010
Volume 8, Issue 1 87-93 doi: 10.2174/157016210790416424
Carpenter S, Dobbs D.Equine infectious anemia virus (EIAV) is one of the most divergent members of the lentivirus subfamily of retroviruses and is considered a useful comparative model for molecular studies of lentivirus replication. The Rev protein of EIAV is functionally homologous with other lentiviral Revs and facilitates export of incompletely spliced viral mRNAs through a Crm1-dependent pathway. The trans- and cis-acting elements that mediate EIAV Rev function are similar to, but distinct from, the well-characterized elements in human immunodeficiency virus (HIV-1), the prototypical Rev protein. In addition,...
Lebelt J, Hagenau K.Borna disease (BD) is a naturally occurring enzootic encephalomyelitis of horses and sheep. The aetiological agent, Borna disease virus (BDV) is an unclassified, neurotropic, negative stranded RNA virus. The study aimed at providing further information on BD of naturally infected animals. Samples obtained from 20 animals (18 horses, 1 donkey, 1 sheep) were investigated by a series of virological and molecular biological tests. The highly sensitive reverse transcription-polymerase chain reaction (RT-PCR) method was used to analyze the tissue distribution of BDV-specific RNA. BDV-specific RNA wa...
Baron AL, Schoeniger A, Becher P, Baechlein C.In recent years, hepatitis C virus (HCV)-related viruses were identified in several species, including dogs, horses, bats, and rodents. In addition, a novel virus of the genus has been discovered in bovine samples and was termed bovine hepacivirus (BovHepV). Prediction of the BovHepV internal ribosome entry site (IRES) structure revealed strong similarities to the HCV IRES structure comprising domains II, IIIabcde, pseudoknot IIIf, and IV with the initiation codon AUG. Unlike HCV, only one microRNA-122 (miR-122) binding site could be identified in the BovHepV 5' nontranslated region. In this ...
Kono Y.The antigenic structure of 16 viruses isolated from four horses which were inoculated with a clone of equine infectious anemia (EIA) virus was compared by the neutralization test. The antigenic structure of viruses isolated after development of neutralizing antibody differed from virus to virus. Back mutation of the antigenic structure was also demonstrated by serial passage of the virus in horses. These results suggest that EIA virus is subject to multidirectional antigenic variation. The possibility that the variants originated in the heterologous virus population in the inoculum seems to be...
Melnick JL, Hampil B.This paper summarizes the results of the fourth part of a comprehensive programme undertaken by the WHO International Reference Centre for Enteroviruses and other laboratories for the testing of enterovirus equine antisera prepared for long-term use as reference antisera. The studies were designed to appraise the specificity of the immune serum of horses inoculated with prototype enteroviruses (coxsackievirus types A2, 4, 8, 10, 11, 14-16, 18-21, and 24, and echoviruses E21, 27, 30, 31, and 33). Tests for neutralizing antibody were performed against the homologous viruses and against available...
Oxburgh L, Hagström A.In this paper we describe the development of a nested RT-PCR assay for the rapid diagnosis and characterisation of influenza virus directly from clinical specimens. Viral RNA is extracted from nasal swabs by the guanidine thiocyanate extraction method, and subsequently reverse transcribed. The complementary DNA is then used as template in a nested PCR reaction. Primers designed for use in this assay are specific for three templates; (1) the nucleoprotein (NP) gene, (2) the haemagglutinin gene of the H7N7 equine influenza virus (A1), and (3) the haemagglutinin gene of the H3N8 equine influenza ...
Babenko VV, Millard A, Kulikov EE, Spasskaya NN, Letarova MA, Konanov DN, Belalov IS, Letarov AV.The viromes of the mammalian lower gut were shown to be heavily dominated by bacteriophages; however, only for humans were the composition and intervariability of the bacteriophage communities studied in depth. Here we present an ecogenomics survey of dsDNA bacteriophage diversity in the feces of horses (), comparing two groups of stabled horses, and a further group of feral horses that were isolated on an island. Our results indicate that the dsDNA viromes of the horse feces feature higher richness than in human viromes, with more even distribution of genotypes. No over-represented phage geno...
Ito M, Itou T, Sakai T, Santos MF, Arai YT, Takasaki T, Kurane I, Ito FH.Brain samples from different animal species including humans: five vampire bats, 14 cattle, 12 dogs, 11 cats, two horses, one pig, one sheep and three humans collected from various geographical regions of Brazil were found to be positive for rabies by means of the fluorescent antibody test (FAT) and the mouse inoculation test (MIT). The brain samples were retested for rabies by means of the reverse transcription and polymerase chain reaction (RT-PCR) with 2 primer sets (P1/P2 and RHNI/RHNS3), which amplified full or partial regions on the nucleoprotein (N) gene of the rabies virus, respectivel...
Charvat RA, Breitenbach JE, Ahn B, Zhang Y, O'Callaghan DJ.Defective interfering particles (DIP) of equine herpesvirus 1 (EHV-1) inhibit standard virus replication and mediate persistent infection. The DIP genome is comprised of only three genes: UL3, UL4, and a hybrid gene composed of portions of the IR4 (EICP22) and UL5 (EICP27) genes. The hybrid gene is important for DIP interference, but the function(s) of the UL3 and UL4 genes are unknown. Here, we show that UL4 is an early gene activated solely by the immediate early protein. The UL4 protein (UL4P) was detected at 4hours post-infection, was localized throughout the nucleus and cytoplasm, and was...
Mittelholzer C, Stadejek T, Johansson I, Baule C, Ciabatti I, Hannant D, Paton D, Autorino GL, Nowotny N, Belák S.To determine a conclusive phylogeny, equine arteritis viruses from Italy, Austria, Hungary, Sweden, South Africa and other parts of the world were analysed by reverse-transcription polymerase chain reaction amplification and direct sequencing. The nucleotide sequences corresponding to the variable part of the large glycoprotein GP5, specified by open reading frame 5, were compared and added to a previously published phylogenetic tree in which a clear division between 'European' and 'American' type viruses had been established. Adding the sequences determined in this study and new sequences ret...
Fares W, Gdoura M, Dhrif H, Touzi H, Hogga N, Hannachi N, Mhalla S, Kacem S, Karray H, Bougatef S, Ben-Alaya N, Triki H.West Nile Virus (WNV) is an arbovirus transmitted by mosquito bite involving birds as reservoirs, humans and equines as accidental hosts. Eight distinct lineages (WNV-1 to WNV-8) have been identified: WNV-1 and WNV-2 infect humans and animals, and WNV-3 to WNV-8 have been identified only in vectors. WNV has been implicated in neuroinvasives infections, especially meningitis and encephalitis. Tunisia experienced three epidemics in 1997, 2003 and 2012. Serological studies on humans, equines and birds as well as the detection of the virus in the vector favour a fairly frequent circulation in the ...
Du J, Wang X, Ma J, Wang J, Qin Y, Zhu C, Liu F, Shao Y, Zhou J, Qiao W, Liu X.The equine infectious anemia virus (EIAV) is a lentivirus of the Retrovirus family, which causes persistent infection in horses often characterized by recurrent episodes of high fever. It has a similar morphology and life cycle to the human immunodeficiency virus (HIV). Its transmembrane glycoprotein, gp45 (analogous to gp41 in HIV), mediates membrane fusion during the infection. However, the post-fusion conformation of EIAV gp45 has not yet been determined. EIAV is the first member of the lentiviruses for which an effective vaccine has been successfully developed. The attenuated vaccine strai...
Current HIV researchMarch 10, 2010
Volume 8, Issue 1 66-72 doi: 10.2174/157016210790416352
Payne SL, Fuller FJ.Equine infectious anemia virus (EIAV) is a macrophage-tropic lentivirus that rapidly Induces disease in experimentally infected horses. Because EIAV infection and replication is centered on the monocyte/macrophage and has a pronounced acute disease stage, it is a useful model system for understanding the contribution of monocyte/macrophages to other lentivirus-induced diseases. Genetic mapping studies utilizing chimeric proviruses in which parental viruses are acutely virulent or avirulent have allowed the identification of important regions that influence acute virulence. U3 regions in the vi...
Calvert AE, Bennett SL, Hunt AR, Fong RH, Doranz BJ, Roehrig JT, Blair CD.Eastern equine encephalitis virus (EEEV), western equine encephalitis virus (WEEV) and Venezuelan equine encephalitis virus (VEEV) can cause fatal encephalitis in humans and equids. Some MAbs to the E1 glycoprotein are known to be cross-reactive, weakly neutralizing in vitro but can protect from disease in animal models. We investigated the mechanism of neutralization of VEEV infection by the broadly cross-reactive E1-specific MAb 1A4B-6. 1A4B-6 protected 3-week-old Swiss Webster mice prophylactically from lethal VEEV challenge. Likewise, 1A4B-6 inhibited virus growth in vitro at a pre-attachm...
Lee J, Park JH, Min JY.The non-structural protein of influenza A virus (NS1A protein) is a multifunctional protein that antagonizes host antiviral responses and contributes to efficient viral replication during infection. However, most of its functions have been elucidated by generating recombinant viruses expressing mutated NS1 proteins that do not exist in nature. Recently, the novel H3N8 A/Equine/Kyonggi/SA1/2011 (KG11) influenza virus was isolated in Korea from horses showing respiratory disease symptoms. KG11 virus contains a naturally truncated NS gene segment with the truncation in the NS1A coding region, res...
Xiao C, Liu Y, Jiang Y, Magoffin DE, Guo H, Xuan H, Wang G, Wang LF, Tu C.Four monoclonal antibodies (mAbs) were generated by immunizing BALB/C mice with recombinant nucleocapsid protein (N) of Nipah virus (NiV) and Hendra virus (HeV) expressed in E. coli. Two mAbs each were obtained for the HeV N and NiV N, respectively. All four mAbs displayed specific reactivity with the recombinant N proteins of both viruses by western blot, which was further confirmed by immunofluorescent antibody assay using fixed insect cells infected with recombinant baculoviruses expressing either the HeV or NiV N protein. Epitope mapping using a 12-mer random peptide phage display library ...
Wang LF, Gould AR, Selleck PW.Full-length cDNA clones coding for the matrix (M) and fusion (F) proteins of equine morbillivirus (EMV) were isolated by RT-PCR, and expressed in Escherichia coli using two different expression systems. Western blot analysis indicated that the M and F proteins, expressed either by itself or as fusion proteins with glutathione S-transferase (GST), were insoluble and degraded after expression. Analysis of the degradation pattern of recombinant M protein suggested that the N-terminus of the matrix protein might be more stable and antigenic than the C-terminal region. Therefore a third system was ...
Fernández-Pinero J, Fernández-Pacheco P, Rodríguez B, Sotelo E, Robles A, Arias M, Sánchez-Vizcaíno JM.A highly sensitive and specific TaqMan-MGB real-time RT-PCR assay has been developed and standardised for the detection of African horse sickness virus (AHSV). Primers and MGB probe specific for AHSV were selected within a highly conserved region of genome segment 7. The robustness and general application of the diagnostic method were verified by the detection of 12 AHSV isolates from all of the nine serotypes. The analytical sensitivity ranged from 0.001 to 0.15 TCID(50) per reaction, depending on the viral serotype. Real-time PCR performance was preliminarily assessed by analysing a panel of...
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...
Gür S, Gürçay M, Seyrek A.Bovine enteroviruses (BEV) are members of Enterovirus genus of the family Picornaviridae. BEV1 has a broad host spectrum, including humans. The virus usually causes subclinical infection, but fatal/severe cases have also been reported in different animal species. There is quite limited data regarding BEV1 in humans. The purpose of this study is to investigate human infection and to identify possible risk factors for viral exposure. For this purpose, blood serum samples (n=1,526) were collected from a city center and nearby villagers simultaneously from humans and farm animals in Elazig provinc...
Birkett AJ, Yélamos B, Rodríguez-Crespo I, Gavilanes F, Peterson DL.The gene coding for the major core protein (p26) of the lentivirus equine infectious anemia virus (EIAV) was cloned from EIAV infected serum, expressed in E. coli, and the resultant protein purified to electrophoretic homogeneity. The protein was expressed in a soluble form and was purified by conventional protein separation methods. When analyzed by SDS-PAGE, under both reducing and non-reducing conditions, the purified protein migrated as a 26 kDa monomer. Recombinant p26 (rp26), therefore, does not contain any intermolecular disulfide bond. Gel filtration chromatography also indicated that ...
Abbas I, Ahmed F, Muqaddas H, Alberti A, Varcasia A, Sedda L.Climate change can cause spatio-temporal shifts in the epidemiology of various vector borne pathogens, especially in vulnerable areas such as the Mediterranean Basin (MB). Among these pathogens, the West Nile virus (WNV) became endemic in the region. This systematic review and meta-analysis study summarizes WNV epidemiology, molecular characteristics, and surveillance in various MB countries, relying on data and scientific articles on WNV published during 2010-2023. The number of published articles varied across the three MB subregions: Southern Europe (n = 153), North Africa (n = 33), and...
Pan J, Ji L, Wu H, Wang X, Wang Y, Wu Y, Yang S, Shen Q, Liu Y, Zhang W, Zhang K, Shan T.Mammals are potential hosts for many infectious diseases. However, studies on the viral communities of herbivorous mammals in the Northwest Plateau are limited. Here, we studied the viral communities of herbivorous mammals in the Northwest Plateau using virus metagenomic analysis to analyze and compare the viral community composition of seven animal species. Results: By library construction and next-generation sequencing, contigs and singlets reads with similar viral sequences were classified into 24 viral families. Analyzed from the perspective of sampling areas, the virus community compositi...
Vissani MA, Alamos F, Tordoya MS, Minatel L, Schammas JM, Dus Santos MJ, Trono K, Barrandeguy ME, Balasuriya UBR, Carossino M.Western equine encephalitis virus (WEEV) is a mosquito-borne arbovirus (genus , family ) that has re-emerged in South America in late 2023, causing severe disease in both horses and humans after a nearly 40-year intermission period. We here describe the virological, serological, pathological, and molecular features of WEEV infection in horses during the 2023-2024 outbreak in Argentina. WEEV-infected horses developed neurological signs with mild to severe encephalitis associated with minimal to abundant WEEV-infected cells, as demonstrated by WEEV-specific in situ hybridization. The distributio...
Eady NA, Holmes C, Schnabel C, Babasyan S, Wagner B.Equine herpesvirus type 1 (EHV-1) is a contagious respiratory pathogen that infects the mucosa of the upper respiratory tract (URT). Mucosal immune responses at the URT provide the first line of defense against EHV-1 and are crucial for orchestrating immunity. To define host-pathogen interactions, we characterized B-cell responses, antibody isotype functions, and EHV-1 replication of susceptible (non-immune) and clinically protected (immune) horses after experimental EHV-1 infection. Nasal secretion and nasal wash samples were collected and used for the isolation of DNA, RNA, and mucosal antib...
Moolla N, Adler D, Blumberg L, Glass A, Grobbelaar A, Le Roux C, Paweska J, Weyer J.Haemorrhagic fever with renal syndrome (HFRS) is caused by hantavirus infection. Hantaviruses are not endemic to South Africa, and we report the first detection of an imported case of HFRS in the country. The case involved a traveller from Croatia who presented to a Johannesburg hospital with an acute febrile illness with renal dysfunction. The patient reported visiting rurally located horse stables in Croatia before falling ill, and that a worker in the stables with similar illness was diagnosed with HFRS. Given the exposure history and clinical findings of the case, a clinical diagnosis of H...
Soghigian J, Andreadis TG, Molaei G.Eastern Equine Encephalitis (EEE) (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne arbovirus that circulates in an enzootic cycle involving Culiseta melanura mosquitoes and wild Passeriformes birds in freshwater swamp habitats. Recently, the northeastern United States has experienced an intensification of virus activity with increased human involvement and northward expansion into new regions. In addition to its principal role in enzootic transmission of EEE virus among avian hosts, recent studies on the blood-feeding behavior of Cs. melanura throughout its geographic range sugg...
