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Ahdy AM, Ahmed BM, Elgamal MA, Shaalan MI, Farag IM, Mahfouz ER, Darwish HR, Sayed-Ahmed MZ, Shalaby MA, El-Sanousi AA. Detection of Equid Alphaherpesvirus 1 from Arabian horses with different clinical presentations between 2016-2019 in Egypt. J Equine Vet Sci 2022; 114:103960. [DOI: 10.1016/j.jevs.2022.103960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/10/2022] [Accepted: 04/11/2022] [Indexed: 01/09/2023]
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin‐Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ, Roberts HC, Padalino B, Pasquali P, Spoolder H, Ståhl K, Calvo AV, Viltrop A, Winckler C, Carvelli A, Paillot R, Broglia A, Kohnle L, Baldinelli F, Van der Stede Y. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): infection with Equine Herpesvirus-1. EFSA J 2022; 20:e07036. [PMID: 35035581 PMCID: PMC8753587 DOI: 10.2903/j.efsa.2022.7036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Equine Herpesvirus-1 infection has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of: Article 7 on disease profile and impacts, Article 5 on the eligibility of the disease to be listed, Article 9 for the categorisation of the disease according to disease prevention and control measures as in Annex IV and Article 8 on the list of animal species related to Equine Herpesvirus-1 infection. The assessment has been performed following a methodology composed of information collection and compilation, and expert judgement on each criterion at individual and collective level. The outcome is the median of the probability ranges provided by the experts, which indicates whether the criterion is fulfilled (66-100%) or not (0-33%), or whether there is uncertainty about fulfilment (33-66%). For the questions where no consensus was reached, the different supporting views are reported. According to the assessment performed, Equine Herpesvirus-1 infection can be considered eligible to be listed for Union intervention according to Article 5 of the Animal Health Law with 33-90% certainty. According to the criteria as in Annex IV of the AHL related to Article 9 of the AHL for the categorisation of diseases according to the level of prevention and control, it was assessed with less than 1% certainty that EHV-1 fulfils the criteria as in Section 1 (category A), 1-5% for the criteria as in Section 2 (category B), 10-66% for the criteria as in Section 3 (category C), 66-90% for the criteria as in Section 4 (category D) and 33-90% for the criteria as in Section 5 (category E). The animal species to be listed for EHV-1 infection according to Article 8(3) criteria are the species belonging to the families of Equidae, Bovidae, Camelidae, Caviidae, Cervidae, Cricetidae, Felidae, Giraffidae, Leporidae, Muridae, Rhinocerontidae, Tapiridae and Ursidae.
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Whitlock FM, Newton JR. A practitioner's guide to understanding equine infectious disease diagnostics in the United Kingdom. Part 1: How to optimise sampling approaches and a guide to agent detection testing methods. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Pusterla N, Leutenegger CM, Wilson WD, Watson JL, Ferraro GL, Madigan JE. Equine Herpesvirus-4 Kinetics in Peripheral Blood Leukocytes and Nasopharyngeal Secretions in Foals Using Quantitative Real-Time TaqMan PCR. J Vet Diagn Invest 2016; 17:578-81. [PMID: 16475518 DOI: 10.1177/104063870501700610] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Based on the hypothesis that the viral load of cells infected with EHV-4 will likely change during the course of disease, TaqMan PCR was used to investigate and characterize the kinetics of EHV-4 viral DNA load (glycoprotein B gene) and transcriptional activity (glycoprotein B and latency-associated transcripts) in peripheral blood leukocytes (PBLs) and nasopharyngeal secretions (NSs) collected from 11 foals during a field outbreak of respiratory disease. The EHV-4 DNA load in PBLs was low and of short duration after onset of clinical signs. In contrast, the EHV-4 load in NSs remained high for the majority of the foals over a period of 4 weeks. Viral replication determined by detection of mRNA expression of the structural glycoprotein B was detected only in NSs during the first 7 days after onset of clinical signs for most foals. The majority of foals expressed latency-associated transcripts in NS sonly during the first 7 days after onset of clinical signs. Persistence of the expression of latency-associated transcripts in NS, as a reflection of a latent viral state, was not documented during the 28-day study period. Based on these results, it was concluded that lytic infection with EHV-4 can be diagnosed either by high EHV-4 DNA load of glycoprotein B gene or by detection of transcriptional activity of glycoprotein B.
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Affiliation(s)
- Nicola Pusterla
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA
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Hu Z, Zhu C, Chang H, Guo W, Liu D, Xiang W, Wang X. Development of a single-tube duplex EvaGreen real-time PCR for the detection and identification of EHV-1 and EHV-4. Appl Microbiol Biotechnol 2014; 98:4179-86. [PMID: 24615388 DOI: 10.1007/s00253-014-5626-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 02/15/2014] [Accepted: 02/17/2014] [Indexed: 12/24/2022]
Abstract
The objective of this study was to develop a novel EvaGreen (EG) based real-time PCR technique for the simultaneous detection of Equine herpesvirus 1 (EHV-1) and Equine herpesvirus 4 (EHV-4) genomes from equine nasal swabs. Viral genomes were identified based on their specific melting temperatures (T m), which are 88.0 and 84.4 °C for EHV-1 and EHV-4, respectively. The detection limitation of this method was 50 copies/μl or 0.15 pg/μl for EHV-1 and 5 copies/μl or 2.5 fg/μl for EHV-4. This assay was 50-1,000 times more sensitive than the SYBR Green (SG)-based assay using the same primer pairs and as sensitive as the TaqMan-MGB probe-based assay. The validity of the real-time PCR assays was confirmed by testing 13 clinical samples. When all results of the EG, SG, and TaqMan probe-based singleplex and duplex real-time PCRs were considered together, a total of 84.6 % (11/13) horses and donkeys were positive for at least one virus. EHV-1 and EHV-4 coexisted in 81.8 % (9/11) horses. Overall, we report that the EvaGreen duplex real-time PCR is an economical and alternative diagnostic method for the rapid differentiation of EHV-1 and EHV-4 in nasal swabs.
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Affiliation(s)
- Zhe Hu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agriculture Sciences, 427 Maduan Street, Harbin, 150001, People's Republic of China
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Ko S, Kang JG, Yeh JY, Moon JS, Choi GC, Won S, Chae JS. First Report on Molecular Detection of Equine Upper Respiratory Infectious Viruses in Republic of Korea. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2012.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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7
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Pusterla N, Hussey SB, Mapes S, Leutenegger CM, Madigan JE, Ferraro GL, Wilson WD, Lunn DP. Comparison of four methods to quantify Equid herpesvirus 1 load by real-time polymerase chain reaction in nasal secretions of experimentally and naturally infected horses. J Vet Diagn Invest 2010; 21:836-40. [PMID: 19901285 DOI: 10.1177/104063870902100611] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The objective of the current study was to compare the performance of 4 methods to quantify Equid herpesvirus 1 (EHV-1) by real-time polymerase chain reaction (PCR) in nasal secretions from experimentally and naturally infected horses. Nasal secretions were collected on the challenge day and daily thereafter for 13 days from 4 experimentally infected horses. Additional nasal swabs were collected from 30 horses with clinical signs consistent with natural EHV-1 infection. Absolute quantitation of EHV-1 target molecules was performed using standard curves for EHV-1 and equine glyceraldehyde-3-phosphate dehydrogenase, and DNA yield, and was expressed as EHV-1 glycoprotein B (gB) gene copies per million nucleated nasal cells, EHV-1 gB gene copies per entire swab, EHV-1 gB gene copies per 1 microl of purified DNA, and EHV-1 gB gene copies per 1 ng of template DNA. The study results showed that all 4 calculation methods yielded comparable results between experimentally and naturally infected horses, and that the different methods were significantly correlated with each other. Reporting of quantitative results for EHV-1 viral load in nasal swabs collected from infected horses constitutes an important advance in both the research and diagnostic fields, allowing one to determine the infectious risk of affected horses, disease stage, or response to antiviral therapy. However, protocols that normalize the PCR results against a preselected volume of DNA or nasal secretions are likely to be more prone to variations than protocols that calculate the load for the entire swab, incorporate a housekeeping gene, or use a constant amount of extracted DNA.
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Affiliation(s)
- Nicola Pusterla
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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9
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Equine herpesvirus-1 myeloencephalopathy: a review of recent developments. Vet J 2008; 180:279-89. [PMID: 18805030 DOI: 10.1016/j.tvjl.2008.08.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 07/30/2008] [Accepted: 08/08/2008] [Indexed: 11/24/2022]
Abstract
Equine herpes myeloencephalopathy (EHM), although a relatively uncommon manifestation of equine herpesvirus-1 (EHV-1) infection, can cause devastating losses on individual farms or boarding stables. Although outbreaks of EHM have been recognized for centuries in domestic horse populations, many aspects of this disease remained poorly characterized. In recent years, an improved understanding of EHM has emerged from experimental studies and from data collected during field outbreaks at riding schools, racetracks and veterinary hospitals throughout North America and Europe. These outbreaks have highlighted the contagious nature of EHV-1 and have prompted a re-evaluation of diagnostic procedures, treatment modalities, preventative measures and biosecurity protocols for the disease. This review concentrates on these and other selected, clinically relevant aspects of EHM.
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Pusterla N, Mapes S, Wilson WD. Use of viral loads in blood and nasopharyngeal secretions for the diagnosis of ehv-1
infection in field cases. Vet Rec 2008; 162:728-9. [DOI: 10.1136/vr.162.22.728] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- N. Pusterla
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; One Shields Avenue Davis CA 95616 USA
| | - S. Mapes
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; One Shields Avenue Davis CA 95616 USA
| | - W. D. Wilson
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; One Shields Avenue Davis CA 95616 USA
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Pusterla N, Wilson WD, Mapes S, Finno C, Isbell D, Arthur RM, Ferraro GL. Characterization of viral loads, strain and state of equine herpesvirus-1 using real-time PCR in horses following natural exposure at a racetrack in California. Vet J 2007; 179:230-9. [PMID: 18024200 DOI: 10.1016/j.tvjl.2007.09.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2007] [Revised: 09/04/2007] [Accepted: 09/13/2007] [Indexed: 11/26/2022]
Abstract
The objective of this study was to determine viral loads, strain (neuropathogenic versus non-neuropathogenic) and state (lytic, non-replicating, latent) of equine herpesvirus-1 (EHV-1) by real-time polymerase chain reaction (PCR) in the blood and nasopharyngeal secretions of adult horses following natural exposure. The index case, a 4-year-old Thoroughbred gelding with confirmed EHV-1 myeloencephalopathy, as well as potentially exposed horses, were sampled over a period of 3 weeks. The study population comprised of 39 adult Thoroughbred horses and 35 adult "pony" and outrider horses of various breeds housed at a racetrack in Northern California. Blood samples and nasopharyngeal secretions (NPS) from all horses were tested on several occasions for EHV-1 DNA viral loads, targeting the glycoprotein B (gB) gene, viral strain, targeting the ORF 30 gene, and transcriptional activity of EHV-1, targeting the gB gene and latency-associated transcripts (LATs). Viral loads and transcriptional activity of the gB gene declined rapidly in the index case following antiviral treatment. The prevalence of EHV-1 infection in NPS determined by PCR slowly decreased over the 22 day study period from 25% to 14%. The initial surveillance showed multiple clusters of exposure, one associated with the index case and two related to horses that had recently returned from a different racetrack. Viral strain differentiation showed that only two horses (the index case and a neighboring horse) were infected with only a neuropathogenic strain, while all other horses were infected with either a non-neuropathogenic strain or were dually infected with both neuropathogenic and non-neuropathogenic strains. In most cases, the virus was present in either a lytic or a non-replicating form, while latent virus was found in blood and NPS much less frequently. The molecular approach used in this study showed promise for assessing the risk of exposing other horses to EHV-1 and for studying viral kinetics in infected horses.
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Affiliation(s)
- Nicola Pusterla
- Department of Medicine and Epidemiology, University of California, Davis, CA 95616, USA
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Wang L, Raidal SL, Pizzirani A, Wilcox GE. Detection of respiratory herpesviruses in foals and adult horses determined by nested multiplex PCR. Vet Microbiol 2007; 121:18-28. [PMID: 17208393 DOI: 10.1016/j.vetmic.2006.11.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 11/08/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
A nested multiplex PCR was developed as a rapid (<12h), sensitive test for the simultaneous identification of equine herpesviruses (EHV1, EHV4, EHV2 and EHV5) in clinical samples from horses. Peripheral blood and nasal swab (NS) samples from 205 weanling Thoroughbred foals on 6 different studs over 3 consecutive seasons and from 92 adult horses without clinical signs of respiratory disease were examined using direct multiplex PCR of clinical samples (direct PCR) and conventional cell culture with differentiation of EHV in cell cultures by multiplex PCR. Multiplex PCR proved a sensitive and specific technique for the detection of EHV in cell culture and clinical samples. The technique described appeared equally sensitive as one using a single set of primers for individual EHV but reduced labour and reagent costs. Cell cultures showing cytopathic effect (CPE) were always positive for EHV on PCR. EHV were also detected by multiplex PCR in 11 samples which failed to show CPE. By a combination of multiplex PCR and cell culture or direct multiplex PCR, the presence of up to three EHV in the same sample was detected. Overall, EHV5 was detected by direct multiplex PCR of peripheral blood mononuclear cells (PBMC) and/or NS samples from 78% of foals and 47% of adult horses. Repeated sampling or cell culture in combination with multiplex PCR and with the incorporation of IL-2 in culture medium increased the sensitivity for detection of EHV in PBMC and demonstrated that EHV5 DNA could be identified in PBMC from 89% of foals and 100% of adult horses. EHV2 was identified from approximately 30% of foals, but was more frequently identified in samples from 17 foals with mild respiratory disease and was isolated infrequently from adult horses. EHV1 and EHV4 were identified uncommonly in any population in the current study.
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Affiliation(s)
- L Wang
- Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA 6150, Australia
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Hussey SB, Clark R, Lunn KF, Breathnach C, Soboll G, Whalley JM, Lunn DP. Detection and quantification of equine herpesvirus-1 viremia and nasal shedding by real-time polymerase chain reaction. J Vet Diagn Invest 2006; 18:335-42. [PMID: 16921871 DOI: 10.1177/104063870601800403] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Equine herpesvirus-1 (EHV-1) infection is common in young horses throughout the world, resulting in respiratory disease, epidemic abortion, sporadic myelitis, or latent infections. To improve on conventional diagnostic tests for EHV-1, a real-time polymerase chain reaction (PCR) technique was developed, using primers and probes specific for the EHV-1 gB gene. Amplification efficiencies of 100% +/- 5% were obtained for DNA isolated from a plasmid, infected peripheral blood mononuclear cells (PBMCs), and nasal secretions from infected ponies. The dynamic range of the assay was 8 log10 dilutions, and the lower limit of detection was 6 DNA copies. Fifteen ponies, seronegative for EHV-1, were experimentally infected with EHV-1, and nasal samples were used to quantify shedding of virus by both virus isolation and real-time PCR analysis. Virus isolation identified nasal shedding of EHV-1 in 12/15 ponies on a total of 25 days; real-time PCR detected viral shedding in 15/15 ponies on 75 days. Viremia was quantified using PBMC DNA, subsequent to challenge infection in 3 additional ponies. Viremia was identified in 1/3 ponies on a single day by virus isolation; real-time PCR detected viremia in 3/3 ponies on 17 days. When real-time PCR was used to analyze PBMC DNA from 11 latently infected ponies (documented by nested PCR), EHV-1 was not detected. We conclude that real-time PCR is a sensitive and quantitative test for EHV-1 nasal shedding and viremia and provides a valuable tool for EHV-1 surveillance, diagnosis of clinical disease, and investigation of vaccine efficacy.
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Affiliation(s)
- Stephen B Hussey
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523, USA
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Brown VA, Wilkins PA. Advanced Techniques in the Diagnosis and Management of Infectious Pulmonary Diseases in Horses. Vet Clin North Am Equine Pract 2006; 22:633-51, xi. [PMID: 16882489 DOI: 10.1016/j.cveq.2006.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Techniques for novel approaches to the diagnosis and management of equine pulmonary disease continue to be developed and used in clinical practice. Diagnostic techniques involving immunoassays and nucleic acid-based tests not only decrease the time in which results become available but increase the sensitivity and specificity of test results. These assays do not substitute for careful clinical evaluation but can shorten the time to a confirmed accurate diagnosis, and thus allow for early initiation of therapeutic strategies and prevention protocols. With further understanding of the molecular biology and immunology of equine pulmonary disease, diagnostic and management techniques should become further refined.
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Affiliation(s)
- Valerie A Brown
- New Bolton Center, University of Pennsylvania School of Veterinary Medicine, 382 West Street Road, Kennett Square, PA 19348, USA.
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Diallo IS, Hewitson G, Wright L, Rodwell BJ, Corney BG. Detection of equine herpesvirus type 1 using a real-time polymerase chain reaction. J Virol Methods 2005; 131:92-8. [PMID: 16137772 DOI: 10.1016/j.jviromet.2005.07.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 07/22/2005] [Accepted: 07/26/2005] [Indexed: 11/20/2022]
Abstract
Equid herpesvirus 1 (EHV1) is a major disease of equids worldwide causing considerable losses to the horse industry. A variety of techniques, including PCR have been used to diagnose EHV1. Some of these PCRs were used in combination with other techniques such as restriction enzyme analysis (REA) or hybridisation, making them cumbersome for routine diagnostic testing and increasing the chances of cross-contamination. Furthermore, they involve the use of suspected carcinogens such as ethidium bromide and ultraviolet light. In this paper, we describe a real-time PCR, which uses minor groove-binding probe (MGB) technology for the diagnosis of EHV1. This technique does not require post-PCR manipulations thereby reducing the risk of cross-contamination. Most importantly, the technique is specific; it was able to differentiate EHV1 from the closely related member of the Alphaherpesvirinae, equid herpesvirus 4 (EHV4). It was not reactive with common opportunistic pathogens such as Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa and Enterobacter agglomerans often involved in abortion. Similarly, it did not react with equine pathogens such as Streptococcus equi, Streptococcus equisimilis, Streptococcus zooepidemicus, Taylorella equigenitalis and Rhodococcus equi, which also cause abortion. The results obtained with this technique agreed with results from published PCR methods. The assay was sensitive enough to detect EHV1 sequences in paraffin-embedded tissues and clinical samples. When compared to virus isolation, the test was more sensitive. This test will be useful for the routine diagnosis of EHV1 based on its specificity, sensitivity, ease of performance and rapidity.
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Affiliation(s)
- Ibrahim S Diallo
- Animal Research Institute, Yeerongpilly Veterinary Laboratory, Department of Primary Industries and Fisheries, Locked Mail Bag 5, Moorooka, Qld 4105, Australia.
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Maeda K, Kai K, Matsumura T. Genomic diversity among equine herpesvirus-4 field isolates. J Vet Med Sci 2005; 67:555-61. [PMID: 15997181 DOI: 10.1292/jvms.67.555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Infection with equine herpesvirus-4 (EHV-4) is a major cause of respiratory tract disease, equine rhinopneumonitis, in horses. Although the full sequence of EHV-4 has been reported, genomic differences among EHV-4 field isolates have not yet been characterized. In this study, the genomic diversity between 23 Japanese EHV-4 isolates was analyzed by digestion with restriction endonucleases (BamHI, BgIII, EcoRI, SacI, and SalI) and polymerase chain reaction (PCR). The restriction endonuclease digestion patterns of the EHV-4 field isolates showed distinct differences which included mobility shifts of some fragments as well as loss and/or gain of fragments. Two EHV-4 genes containing repeat sequences, ORFs 24 and 71, were amplified by PCR and the amplified fragments were compared among the field isolates. The sizes of the amplified fragments varied among epizootiologically unrelated isolates, while the fragments of related isolates had the same size. The observed genomic diversity among EHV-4 field isolates may be a useful tool for epidemiological study of equine rhinopneumonitis by EHV-4 infection.
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Affiliation(s)
- Ken Maeda
- Department of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, Yoshida, Japan
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Frisbie DD, McIlwraith CW. Gene therapy: future therapies in osteoarthritis. Vet Clin North Am Equine Pract 2005; 17:233-43, vi. [PMID: 15658173 DOI: 10.1016/s0749-0739(17)30059-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The field of equine veterinary practice is in an ever-evolving state, requiring current technologies to be constantly evaluated for new applications. The specific use of gene therapy in the horse is a novel application. The authors want to help familiarize the equine practitioner with the concept of gene therapy, and introduce its use and potential future benefits for the equine industry in the treatment of osteoarthritis.
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Affiliation(s)
- D D Frisbie
- Department of Clinical Sciences, Colorado State University College of Veterinary Medicine and Biomedical Sciences, Fort Collins, Colorado 80524, USA.
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Hartley CA, Wilks CR, Studdert MJ, Gilkerson JR. Comparison of antibody detection assays for the diagnosis of equine herpesvirus 1 and 4 infections in horses. Am J Vet Res 2005; 66:921-8. [PMID: 15934623 DOI: 10.2460/ajvr.2005.66.921] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare methods of detecting equine herpesvirus type 1 (EHV1)- and EHV4-specific antibodies in horse sera. SAMPLE POPULATION 33 acute and convalescent serum samples from experimentally or naturally infected horses after confirmed EHV1 or EHV4 infection. PROCEDURE For each sample, serum antibody titers against EHV1 and EHV4 were determined by use of virus neutralization (VN) and complement fixation (CF) assays. The ELISA absorbance values for each serum sample were determined against the EHV1 and EHV4 recombinant ELISA antigens. Values obtained for acute and convalescent sera in each assay were compared. RESULTS Following experimental infection of foals, EHV1 or EHV4 antibodies that were specific for the inoculating virus were detected only by use of the ELISA. Results of VN and CF assays indicated that the foals seroconverted to EHV1 and EHV4 following infection with EHV4 only. After EHV1-induced abortion, myeloencephalitis, or respiratory tract disease, the VN and CF assay results revealed seroconversion to EHV1 and EHV4, whereas results of the ELISA revealed seroconversion to EHV1 only. Similarly, after confirmed EHV4-induced respiratory tract disease, increases in EHV4-specific antibodies were detected only by use of the ELISA with no indication of an increase in EHV1 antibodies. The CF and, to a lesser degree, VN assays revealed that seroconversion to EHV1 and EHV4 occurred between the time of obtaining acute and convalescent serum samples. CONCLUSIONS AND CLINICAL RELEVANCE The EHV1/EHV4 type-specific antibody ELISA clearly identifies horses that have been infected with EHV1 or EHV4 by use of acute and convalescent sera. Results of VN and CF assays indicate that cross-reactive antibodies greatly limit their use.
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Affiliation(s)
- Carol A Hartley
- School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
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20
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Daly P, Doyle S. The development of a competitive PCR-ELISA for the detection of equine herpesvirus-1. J Virol Methods 2003; 107:237-44. [PMID: 12505639 DOI: 10.1016/s0166-0934(02)00252-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Equine herpesvirus-1 (EHV-1) infection is of significant animal welfare and economic importance. Yet, no standardised molecular techniques are available for diagnosis or confirmation of viral infection. The purpose of this study was to develop a standardised and quantitative assay system for the reliable detection of EHV-1 infection which was capable of eliminating the likelihood of false negative results. A region within the EHV-1 glycoprotein B gene was amplified by polymerase chain reaction (PCR), cloned and subjected to site-directed mutagenesis to generate a control plasmid, amplifiable by identical primers to wild type EHV-1, yet capable of detection by an alternate dinitrophenylated oligonucleotide probe in a PCR-ELISA system. A competitive PCR-ELISA system which can control for the presence of PCR inhibitors and which is capable of detecting 63 genome equivalents of EHV-1 has been developed. EHV-1 presence in infected equine tissue and cell culture material was demonstrated using this system. The entire assay can be completed within one working day and facilitates multiple sample analysis. The availability of a robust, competitive PCR-ELISA system for the detection of EHV-1 will facilitate the rapid and sensitive detection of EHV-1 and offers the potential for eliminating the occurrence of abortion storms in stud farms.
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Affiliation(s)
- P Daly
- National Institute for Cellular Biotechnology, Department of Biology, National University of Ireland, Maynooth Co., Kildare, Ireland
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Varrasso A, Dynon K, Ficorilli N, Hartley CA, Studdert MJ, Drummer HE. Identification of equine herpesviruses 1 and 4 by polymerase chain reaction. Aust Vet J 2001; 79:563-9. [PMID: 11599819 DOI: 10.1111/j.1751-0813.2001.tb10751.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To develop and validate specific, sensitive and rapid (< 8 hour) diagnostic tests using polymerase chain reaction (PCR) for the diagnosis of abortion and respiratory disease caused by equine herpesvirus 1 (EHV1; equine abortion virus) and EHV4 (equine rhinopneumonitis virus). DESIGN Primer sets based on nucleotide sequences encoding glycoprotein H (gH) of EHV1 and gB of EHV4 were designed and used in single round and second round (seminested) PCRs, and in a multiplex PCR for the diagnosis of EHV1 and EHV4 infections. METHODS Oligonucleotide primers were designed for each virus, PCR conditions were defined and the specificity and sensitivity of the assays were determined. The tests were applied to tissue samples from aborted equine foetuses and to nasopharyngeal swabs from horses with acute febrile respiratory disease. RESULTS Individual single round and a second round (seminested) EHV1 and EHV4 PCRs were specific in that EHV1 primers amplified all (n = 30) EHV1 isolates and did not amplify EHV4. Similarly EHV4 primers amplified all (n = 6) EHV4 isolates and did not amplify EHV1. Both PCRs were sensitive in that the first round EHV1 PCR detected 1220 molecules of EHV1 plasmid DNA and the first round EHV4 PCR detected 7280 molecules of EHV4 plasmid DNA. The EHV1 second round PCR was 100 times more sensitive in that it detected 12 molecules of EHV1 DNA and the EHV4 second round PCR was 1000 times more sensitive in that it detected 8 molecules of EHV4 DNA. There was a high correlation between detection of EHV1 by virus isolation and PCR when tissue samples from 71 aborted foetuses were examined; all samples positive by virus isolation were positive by PCR. Similarly the EHV4 PCR was at least as sensitive as virus isolation when applied to nasaopharyngeal swabs from horses with respiratory disease in that all samples positive by virus isolation were also positive by PCR. CONCLUSION Individual single round and second round (seminested) PCRs and a seminested multiplex PCR were developed that enabled reliable, rapid detection of EHV1 and EHV4 in aborted foetal tissues and nasopharyngeal swab samples.
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Affiliation(s)
- A Varrasso
- Centre for Equine Virology, School of Veterinary Science, The University of Melbourne, Parkville, Victoria
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23
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Galosi CM, Vila Roza MV, Oliva GA, Pecoraro MR, Echeverría MG, Corva S, Etcheverrigaray ME. A polymerase chain reaction for detection of equine herpesvirus-1 in routine diagnostic submissions of tissues from aborted foetuses. JOURNAL OF VETERINARY MEDICINE. B, INFECTIOUS DISEASES AND VETERINARY PUBLIC HEALTH 2001; 48:341-6. [PMID: 11471844 DOI: 10.1046/j.1439-0450.2001.00455.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Equine herpesvirus 1 (EHV-1) is the causative agent of abortion, perinatal foal mortality, neurological and acute respiratory diseases in horses. Conventional laboratory diagnosis involving viral isolation from aborted foetuses is laborious and lengthy and requires processing of samples within 24 h of collection, which is problematic for samples that come from long distances. The aim of this study was to develop a polymerase chain reaction (PCR) assay useful in Argentina to detect DNA sequences of EHV-1 in different tissues from aborted equine foetuses with variable quality of preservation and without the use of conventional DNA fenolic extraction. Several DNA extraction protocols and primers were evaluated. The amplification method was standardized and its specificity was analysed using 38 foetal samples of variable quality of preservation. Of the 38 different foetal tissues, nine livers, six spleens and two lungs in good preservation and eight livers, one spleen and four lungs in a poor state of preservation were positive for PCR. EHV-1 was recovered only from the nine livers, five spleens and two lungs in good preservation. No virus was isolated from the samples that were poorly preserved. Viral isolation was confirmed by cytopathic effect and indirect immunofluorescence. The specificity of the PCR results was confirmed by the restriction endonuclease digestion of PCR products and hybridization.
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Affiliation(s)
- C M Galosi
- Department of Virology, Faculty of Veterinary Sciences, National University of La Plata, Argentina.
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24
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Carvalho R, Passos L, Oliveira A, Henry M, Martins A. Detection of equine herpesvirus 1 DNA in a single embryo and in horse semen by polymerase chain reaction. ARQ BRAS MED VET ZOO 2000. [DOI: 10.1590/s0102-09352000000400002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The genome of one equine embryo and three equine semen specimens collected from a Brazilian farm were tested by polymerase chain reaction (PCR) for the presence of EHV-1 and EHV-4-specific timidine kinase (TK) sequences. The PCR detected specific EHV-1 TK gene sequences in all samples tested. The peripheral blood leukocytes (PBL) of the embryo donor mare also was amplified by EHV-1 TK primers. Infectious virus was not recovered from any specimens. The animals did not show any clinical signal of EHV-1 or EHV-4 infections. EHV-4 was not detected in the studied specimens. The results indicate that PCR was more sensitive than virus isolation in cell culture for detecting EHV-1 in semen of carrier horses.
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Affiliation(s)
- R. Carvalho
- Ministério da Agricultura e do Abastecimento
| | | | | | - M. Henry
- Universidade Federal de Minas Gerais
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25
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Carvalho R, Passos LM, Martins AS. Development of a differential multiplex PCR assay for equine herpesvirus 1 and 4 as a diagnostic tool. JOURNAL OF VETERINARY MEDICINE. B, INFECTIOUS DISEASES AND VETERINARY PUBLIC HEALTH 2000; 47:351-9. [PMID: 10900826 DOI: 10.1046/j.1439-0450.2000.00361.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In this study, a multiplex polymerase chain reaction (PCR) procedure was developed for differentiation of strains and field isolates of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4). Specific oli-gonucleotide primers were combined to amplify the thymidine kinase (TK) gene region of EHV-1 and EHV-4, which would yield fragments of different lengths for each virus in the same amplification reaction. The specificity of the largest PCR amplicon for EHV-4 was confirmed by restriction digestion with HindIII. The multiplex PCR proved to be a fast and sensitive method for typing EHV-1 and EHV-4 isolates and for detection and differentiation of both viruses in field samples in which infectious virus is no longer available. The sensitivity was improved by combining cycling optimization and visualization of PCR products in ethidium bromide and silver-stained acrylamide gels.
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Affiliation(s)
- R Carvalho
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, UFMG, Belo Horizonte, Brazil
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26
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Friday PA, Scarratt WK, Elvinger F, Timoney PJ, Bonda A. Ataxia and Paresis with Equine Herpesvirus Type 1 Infection in a Herd of Riding School Horses. J Vet Intern Med 2000. [DOI: 10.1111/j.1939-1676.2000.tb02236.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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27
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Perkins G, Ainsworth DM, Erb HN, Del Piero F, Miller M, Wilkins PA, Palmer J, Frazer M. Clinical, haematological and biochemical findings in foals with neonatal Equine herpesvirus-1 infection compared with septic and premature foals. Equine Vet J 1999; 31:422-6. [PMID: 10505959 DOI: 10.1111/j.2042-3306.1999.tb03843.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A retrospective multicentre study comparing historical, clinical, haematological, acid-base and biochemical findings of foals with Equine herpesvirus-1 (EHV-1) infection, septicaemia or prematurity was performed to determine if early diagnosis of EHV-1 foals was possible. Fifty-three foals were studied and were assigned to one of 2 groups: herpes positive (n = 14) or herpes negative (n = 39). The latter group included 20 septic, 11 premature, and 8 premature and septic foals. The presence of herpes antigen was confirmed by immunoperoxidase histochemical staining of tissues from necropsied foals. A nonparametric statistical analysis followed by a backwards elimination logistic regression was performed to establish a model at a P value of <0.05. All herpes positive foals died, while 47% (9/19) of the septic foals survived. Based upon our analysis, herpes positive foals were more likely to have total white blood cell counts less than 3 x 10(9)/l and to be icteric as compared to the septic and premature foals. Despite profound hepatic necrosis in the herpes positive foals, liver enzymes were not elevated and were not significantly different from the controls.
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Affiliation(s)
- G Perkins
- Department of Clinical Sciences, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853, USA
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28
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Desmettre P. Diagnosis and prevention of equine infectious diseases: present status, potential, and challenges for the future. ADVANCES IN VETERINARY MEDICINE 1999; 41:359-77. [PMID: 9890028 DOI: 10.1016/s0065-3519(99)80027-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The frequent transfers of horses, whether on a permanent or temporary basis, make strict control of infectious diseases essential. Such control needs a reliable and rapid means to accurately diagnose the relevant diseases. Indirect diagnosis based on antibody detection remains certainly the best method to secure the epidemiologic surveillance of the diseases at regional, national, or even world level, while direct diagnosis is the only way to diagnose a new outbreak. New diagnostic methods resulting from advances in biochemistry, molecular biology, and immunology are now available. As far as antibody detection is concerned, the new methods are mainly based on immunoassays, especially ELISAs. Regarding the identification of the pathogens, while isolation is still of importance, much progress has been made with immunocapture tests including capture ELISA based on monoclonal antibodies. DNA probes and amplification tests such as PCR or RT-PCR are representing a real breakthrough. Factors common to all of these tests are specificity, sensitivity, rapid implementation, and quick results. Such tests are, however, often still at the development stage. They absolutely need to be validated under multicentric evaluations prior to being used on a larger scale. At the same time there is an obvious need for the standardization of the reagents used. The technical and economic impact of a false (either positive or negative) diagnosis justifies such an harmonization which could effectively be achieved worldwide under the aegis of the Office International des Epizooties (OIE), which is itself the primary source of disease information. Vaccines are also essential for the control of equine infectious diseases. Most vaccines used in the prevention of viral or bacterial diseases are inactivated adjuvanted vaccines, which may cause unacceptable side effects. Also, their efficacy can sometimes be questioned. Subunit vaccines, when available, represent significant advances especially with regards to safety. Greater progress is expected from the use of new technologies taking advantage of recent developments in molecular biology (recombinant DNA technology) and in immunology (immunomodulators). Significant results have been obtained with subunit vaccines or with live vectored vaccines using recombinant DNA technology. Good results are on the way to be achieved with genetic (or naked-DNA) vaccines. It is therefore possible to expect the availability of a new generation of vaccines in the rather short term. Such vaccines will not only be safer and more efficacious, but they will also make it possible to differentiate vaccinated from infected animals, which will contribute to better control of the infection. Whatever the quality of the vaccines of the future may be, vaccination alone will never be sufficient to control infectious diseases. It is therefore essential to keep on making the animal owners and their veterinarians aware of the importance of the management and the hygiene in the diseases control and to organize them under "Common Codes of Practice."
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29
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Yasunaga S, Maeda K, Matsumura T, Kai K, Iwata H, Inoue T. Diagnosis and sero-epizootiology of equine herpesvirus type 1 and type 4 infections in Japan using a type-specific ELISA. J Vet Med Sci 1998; 60:1133-7. [PMID: 9819768 DOI: 10.1292/jvms.60.1133] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recently, a type-specific ELISA using equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) glycoprotein Gs (gGs) was developed by Crabb and Studdert [1993]. To investigate the dissemination of EHV-1 and -4 among horses in Japan, we applied their ELISA as suitable for discriminating between EHV-1 and -4 infections serologically. Type-specificity of the ELISA was confirmed by using paired sera of infected horses with either EHV-1 or -4. Application of the ELISA to sera collected before and after the winter season of 1995-1996 from 80 racehorses revealed that 30 horses showed significant antibody responses against EHV-1 and 9 against EHV-4, respectively. The results indicated that this ELISA using paired sera is useful for a diagnosis and an epizootiological study on EHV-1 and -4 infections.
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Affiliation(s)
- S Yasunaga
- Department of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, Japan
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30
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Abstract
The polymerase chain reaction (PCR) is a nucleic acid-based technique that enables the rapid and sensitive detection of specific micro-organisms. Although this technique is widely used in veterinary research, it has not yet found applications in routine microbiological analysis of veterinary clinical samples. However, advances in sample preparation together with the increasing availability of specific gene sequences will probably lead to the more widespread diagnostic use of PCR in the future. PCR is likely to have a strong impact in the epidemiology, treatment and prevention of animal infectious diseases.
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Affiliation(s)
- J M Rodriguez
- Departamento de Nutrición y Bromatología III, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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31
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Abstract
Myeloencephalopathy is an uncommon manifestation of equine herpesvirus 1 (EHV-1), but it can cause devastating losses during outbreaks on individual farms. Clinical signs of neurologic disease reflect a diffuse multifocal hemorrhagic myeloencephalopathy secondary to vasculitis and thrombosis. Sudden onset and early stabilization of signs, including ataxia, paresis, and urinary incontinence; involvement of multiple horses on the premises; and recent history of fever, abortion, or viral respiratory disease in the affected horse or herdmates are typical features, although there is considerable variation between outbreaks in epidemiologic and clinical findings. Prevention is difficult because many asymptomatic horses are infected latently with EHV-1 myeloencephalopathy and because vaccines do not confer protection against neurologic manifestations of infection. This article reviews the pathogenesis, pathology, clinical manifestations, diagnosis, and treatment of EHV-1 myeloencephalopathy and discusses prevention and control of equine herpesviral infections in the context of their epidemiology.
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Affiliation(s)
- W D Wilson
- Department of Medicine and Epidemiology, University of California, Davis, School of Veterinary Medicine, USA
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32
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Ishiyama T, Nishimori T, Kato M, Yamada H, Sato K, Sentsui H. Direct detection of equine herpesvirus DNA in tissues of aborted equine fetuses. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1996; 43:639-42. [PMID: 9011160 DOI: 10.1111/j.1439-0450.1996.tb00363.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Restriction endonuclease analysis of equine herpesviruses 1 (EHV-1) and 4 has been investigated using cultured cells infected with these viruses. The DNA cleavage patterns of these viruses were observed in the intracellular DNA after digestion with Eco RI and electrophoresis. This procedure was applied to the diagnosis of equine herpesvirus infection in aborted equine fetuses. The characteristic Eco RI restriction pattern of EHV-1 DNA was directly detectable in the emulsion of lungs collected from aborted equine fetuses.
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Affiliation(s)
- T Ishiyama
- Hokkaido Branch, National Institute of Animal Health, Japan
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33
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Mackie JT, MacLeod GA, Reubel GH, Studdert MJ. Diagnosis of equine herpesvirus 1 abortion using polymerase chain reaction. Aust Vet J 1996; 74:390-1. [PMID: 8941422 DOI: 10.1111/j.1751-0813.1996.tb15452.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J T Mackie
- Department of Agriculture, Benalla, Victoria
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34
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Lyaku JR, Vilcek S, Nettleton PF, Marsden HS. The distinction of serologically related ruminant alphaherpesviruses by the polymerase chain reaction (PCR) and restriction endonuclease analysis. Vet Microbiol 1996; 48:135-42. [PMID: 8701569 DOI: 10.1016/0378-1135(95)00136-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The amplification and analysis of a 468bp fragment from the gB gene of the serologically related ruminant alphaherpesviruses bovine herpesvirus-1.1 and 1.2 (BHV-1.1 and BHV-1.2), caprine herpesvirus-1 (CapHV-1), cervine herpesvirus-1 (CerHV-1) and rangiferine herpesvirus-1 (RanHV-1) by PCR and restriction endonuclease analysis is described. As primers, 22bp oligomers selected from the BHV-1 gB gene sequences were used for the amplification of the DNA from the five viruses. The amplification product from each virus was analysed by the restriction endonuclease enzymes BglI, HinfI, SmaI and AvaI. The specific amplification obtained demonstrate the existence of the gB gene sequences for each of the five alphaherpesviruses. However, sequences from some of the fragments were found to be different from those predicted from the gB gene following restriction endonuclease analysis. All five amplification products generated the same number of fragments after digestion with HinfI except for two additional bands evident in CapHV-1. The CerHV-1 and RanHV-1 fragments contained slightly different BglI restriction sites from those of the other three. While BHV-1.1, BHV-1.2, CapHV-1 and CerHV-1 contained SmaI and AvaI restriction sites, the RanHV-1 amplification product lacked both SmaI and AvaI restriction sites.
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Affiliation(s)
- J R Lyaku
- Moredun Research Institute, Edinburgh, UK
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35
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Baxi MK, Borchers K, Bartels T, Schellenbach A, Baxi S, Field HJ. Molecular studies of the acute infection, latency and reactivation of equine herpesvirus-1 (EHV-1) in the mouse model. Virus Res 1996; 40:33-45. [PMID: 8725119 DOI: 10.1016/0168-1702(95)01255-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The murine intranasal (i.n.) infection model was used to study the molecular distribution of equine herpesvirus-1 (EHV-1) during acute infection, latency and following a reactivation stimulus. After inoculation, infectious virus was detected in lungs, nasal turbinates, brains and olfactory bulbs during the acute phase. A nested PCR (nPCR) readily detected virus in these tissues and, in addition, virus was detected in spleens and (in the second round of nPCR) in peripheral blood mononuclear cells (PBMC). A digoxigenin-labelled in situ hybridization probe detected EHV-1 DNA in bronchiolar and vascular endothelium in the lungs and in and around germinal centres in the spleens. One month later, although infectious virus was absent from all tissues, the trigeminal ganglia, olfactory bulb and PBMC remained positive for virus DNA although this was detected only on the second round of nPCR. Furthermore, in situ hybridization, using either DNA or RNA probes, suggested that little or no transcription of virus occurred in neural tissues during the 'latent phase'. Following a reactivation stimulus, infectious virus was not isolated from any tissues, however, EHV-1 DNA was detected on the first round of nPCR in olfactory bulb, trigeminal ganglia and PBMC. This suggested a quantitative increase in EHV-1 DNA occurred following reactivation stimulus. The significance of these results is discussed in relation to the molecular state of EHV-1 in different tissues at various stages of infection and the validity of the murine model for studying latency and reactivation of EHV-1 in the horses.
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Affiliation(s)
- M K Baxi
- Centre for Veterinary Science, Cambridge University Veterinary School, UK
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36
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Onions D. The implications of biotechnology for equine practice. Equine Vet J 1995; 27:404-5. [PMID: 8565935 DOI: 10.1111/j.2042-3306.1995.tb04418.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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37
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Rimstad E, Hyllseth B. Equine herpesviruses 1 and 4: amplification and differentiation by polymerase chain reaction. Acta Vet Scand 1995. [PMID: 7847200 DOI: 10.1186/bf03548336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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38
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McCann SH, Mumford JA, Binns MM. Development of PCR assays to detect genetic variation amongst equine herpesvirus-1 isolates as an aid to epidemiological investigation. J Virol Methods 1995; 52:183-94. [PMID: 7769032 DOI: 10.1016/0166-0934(94)00162-a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A search for variable restriction sites has been carried out for equine herpesvirus-1 (EHV-1) in an attempt to develop markers which can be used to group epidemiologically related viruses into groups, and to learn more about the dynamics of EHV-1 disease. Crude viral DNA extracts of EHV-1, prepared by Hirt extraction, were digested with AluI, HaeIII, or RsaI, and Southern blotted following electrophoresis. DNA fingerprints, produced by probing the Southern blots with the EHV-1 EcoR1-I fragment, separated 56 isolates into 16 groups. The variable sites within the EcoR1-I fragment were mapped approximately using fragments from within EcoR1-I, and the precise location of the variable sites determined from the DNA sequence of this fragment. Oligonucleotide primers flanking the variable sites were synthesized, and used in PCR assays to detect variable fragments. The AluI variable fragment was found to result from the presence or absence of a single AluI site. In contrast, the variable bands seen with HaeIII and RsaI, resulted from variation in the copy number of two tandemly repeated sequences, one of which had not previously been recognized. In addition, HaeIII digests of EHV-1 isolates probed with the glycoprotein B (gB) gene of EHV-1 also separated isolates into two groups. The variable HaeIII site was mapped towards the 5'-end of the gB gene and a PCR assay established. The distribution of the variable AluI site within the EcoR1-I fragment and the HaeIII site within the gB gene were estimated on a large number of clinical isolates using PCR on unpurified viral tissue culture medium. Both sites had a good distribution and together with additional variable sites should provide the basis for the rapid DNA fingerprinting of EHV-1 isolates.
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Affiliation(s)
- S H McCann
- Department of Infectious Diseases, Animal Health Trust, Newmarket, Suffolk, UK
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39
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Pfeffer M, Wiedmann M, Batt CA. Applications of DNA amplification techniques in veterinary diagnostics. Vet Res Commun 1995; 19:375-407. [PMID: 8560754 PMCID: PMC7089009 DOI: 10.1007/bf01839319] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/1995] [Indexed: 01/31/2023]
Abstract
An overview of the principles of the polymerase chain reaction, ligase chain reaction, self-sustained sequence replication and Q beta replicase is given. The application of these methods for the diagnosis of veterinary infectious and hereditary diseases as well as for other diagnostic purposes is discussed and comprehensive tables of reported assays are provided. Specific areas where these DNA-based amplification methods provide substantial advantages over traditional approaches are also highlighted. With regard to PCR-based assays for the detection of viral pathogens, this article is an update of a previous review by Belák and Ballagi-Pordány (1993).
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Affiliation(s)
- M Pfeffer
- Institute for Medical Microbiology, Infectious and Epidemic Diseases, Ludwig-Maximilians University, Munich, Germany
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40
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Crabb BS, Studdert MJ. Equine herpesviruses 4 (equine rhinopneumonitis virus) and 1 (equine abortion virus). Adv Virus Res 1995; 45:153-90. [PMID: 7793324 DOI: 10.1016/s0065-3527(08)60060-3] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- B S Crabb
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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41
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Osterrieder N, Hübert PH, Brandmüller C, Kaaden OR. A touchdown PCR for the differentiation of equine herpesvirus type 1 (EHV-1) field strains from the modified live vaccine strain RacH. J Virol Methods 1994; 50:129-36. [PMID: 7714035 DOI: 10.1016/0166-0934(94)90169-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
More than 50 reference strains and field isolates of equine herpesvirus type 1 (EHV-1) were examined by a touchdown PCR. Primers for specific amplification of EHV-1 DNA were chosen from the terminal and internal repeat regions of the EHV-1 genome where the high-passaged live vaccine strain RacH displays symmetric 850 bp deletions. The positive strand and one negative strand primer were designed to encompass the deletions present in RacH, and the second negative strand primer was designed to hybridize within these deletions. Discrimination between field isolates and the vaccine strain was achieved by the generation of amplification products of different size: In all EHV-1 reference strains and field isolates, a 495 bp DNA fragment was amplified specifically, whereas a 310 bp fragment was amplified when DNA of the vaccine strain RacH was used as a template. PCR amplification was only obtained in the presence of 8-10% dimethylsulfoxide and when the primer annealing temperatures were decreased stepwise from 72 degrees C to 60 degrees C. Under these conditions as little as 100 fg template DNA, corresponding to about 100 genome equivalents, could be detected. The PCR assay allows fast and sensitive discrimination of the modified live vaccine strain RacH from field strains of EHV-1 since it is applicable to viral DNA extracted from organ samples and paraffin-embedded tissues. It may thus be helpful for examining the potential involvement of the RacH live vaccine strain in abortions of vaccinated mares.
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Affiliation(s)
- N Osterrieder
- Institute for Medical Microbiology, Ludwig-Maximilians-University Munich, Germany
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42
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Vilcek S, Nettleton PF, Herring JA, Herring AJ. Rapid detection of bovine herpesvirus 1 (BHV 1) using the polymerase chain reaction. Vet Microbiol 1994; 42:53-64. [PMID: 7839585 DOI: 10.1016/0378-1135(94)90077-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A polymerase chain reaction (PCR) assay based on primers from the viral gI glycoprotein gene detected 3 fg pure BHV-1 DNA, 0.1-1.0 TCID50 or a single infected cell. No amplification was observed with DNA from BHV-2, BHV-3, BHV-4, OHV-1 or OHV-2. However, a fragment of the correct size was amplified using DNA from herpesviruses isolated from reindeer, red deer and goats. The PCR assay was able to detect virus in nasal swabs up to 14 days after experimental infection of cattle and there was a good correlation when PCR was compared with virus isolation for the detection of BHV-1 in clinical field samples. Detection of BHV-1 in fetal bovine serum and semen samples was also successful.
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Affiliation(s)
- S Vilcek
- Moredun Research Institute, Edinburgh, UK
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Lawrence GL, Gilkerson J, Love DN, Sabine M, Whalley JM. Rapid, single-step differentiation of equid herpesviruses 1 and 4 from clinical material using the polymerase chain reaction and virus-specific primers. J Virol Methods 1994; 47:59-72. [PMID: 8051234 DOI: 10.1016/0166-0934(94)90066-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Sets of primers were designed which enabled specific amplification of homologous regions of the glycoprotein C and gene 76 genetic loci of equine herpesviruses 1 and 4 (EHV-1 and EHV-4). The resultant virus-specific polymerase chain reaction (PCR) products arising from each loci could be discriminated easily on the basis of size on an agarose gel, allowing rapid differentiation of the two equine herpesviruses. Specificity of the amplifications were confirmed by Southern hybridization and restriction endonuclease digestion. The PCR test was applied to nasal swab samples from weanling foals and to archival aborted fetal tissue samples and the results compared to those obtained by virus isolation. A strong correlation was found between this PCR assay and virus isolation methods of EHV-1 and EHV-4 detection and discrimination.
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Affiliation(s)
- G L Lawrence
- School of Biological Sciences, Macquarie University, Sydney, N.S.W., Australia
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44
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Gilkerson J, Jorm LR, Love DN, Lawrence GL, Whalley JM. Epidemiological investigation of equid herpesvirus-4 (EHV-4) excretion assessed by nasal swabs taken from thoroughbred foals. Vet Microbiol 1994; 39:275-83. [PMID: 8042275 DOI: 10.1016/0378-1135(94)90164-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Equid herpesvirus-4 (EHV-4) was detected in nasal swabs taken from foals using a PCR based test and this information used to study the epidemiology of EHV-4 disease on three Australian Thoroughbred stud farms in NSW in 1992. There was a very high level of agreement (kappa value of 0.84) between the PCR results and virus isolation using cell culture techniques. There was a strong seasonal distribution of EHV-4 shedding. Twenty-five of 26 positive samples were collected in January and March with the remaining positive sample collected in February. Foals with clinical signs of upper respiratory tract infection per se were no more likely to be shedders of EHV-4 (odds ratio [OR] 1.4, 95% confidence limits [CL] 0.5-3.8). However, EHV-4 was more likely to be isolated from foals exhibiting copious serous or mucopurulent nasal discharge than those with no clinical signs (OR 4.6, 95% CL 1.1-19.0 and OR 2.5, 95% CL 0.8-8.0, respectively). The month of the year was more important than weaning or age as a risk factor for excretion of EHV-4. Male foals and those with a history of respiratory disease that had required veterinary treatment were more likely to shed EHV-4.
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Affiliation(s)
- J Gilkerson
- Department of Veterinary Pathology, University of Sydney, NSW, Australia
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45
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Abstract
The nested PCR method was applied for the detection and direct differentiation of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4). Primer pairs were chosen from the glycoprotein B (gB) coding region of each serotype. The outer and inner EHV-1 primer pairs were type-specific, whereas the outer EHV-4 primer pair amplified EHV-1 and EHV-4 DNA and was therefore suitable for the detection of both virus types in a single sample. However, the nested EHV-4 primer pair was type-specific. The advantages of the nested PCR are twofold. Firstly, this assay was in the case of EHV-1 100 times, and in the case of EHV-4 1000 times more sensitive than the standard PCR, which indicates a detection limit of 1-0.1 fg of DNA (3-1 genome equivalents). Secondly, it allows the direct differentiation of EHV-1 and -4 without the need to resort to further analytical techniques.
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Affiliation(s)
- K Borchers
- Institut für Virologie der Freien Universität Berlin, Germany
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46
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Abstract
Two viruses, EHV-1 and EHV-4, are now known to be responsible for disease conditions formerly considered caused by "equine rhinopneumonitis virus." Although these viruses share several laboratory and clinical features, they differ in epidemiology and pathogenic potential. EHV-4 is primarily associated with clinical respiratory disease, whereas EHV-1 is more frequently isolated from aborted fetuses, sickly foals, and neurologic cases. Both viruses frequently establish latent infections, but the relevance of latency to clinical disease is unclear. Diagnosis based on identification of the pathogen is generally superior to serologic methods. Vaccines containing each virus are available, and vaccination in concert with careful management limits the number of clinical cases. Immunity following vaccination or disease is not absolute, however, and improved disease prophylaxis awaits a better understanding of protective immune responses.
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Affiliation(s)
- E N Ostlund
- Department of Veterinary Science, University of Kentucky, Lexington
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47
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Kirisawa R, Endo A, Iwai H, Kawakami Y. Detection and identification of equine herpesvirus-1 and -4 by polymerase chain reaction. Vet Microbiol 1993; 36:57-67. [PMID: 8236780 DOI: 10.1016/0378-1135(93)90128-t] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A rapid method for detection and identification of equine herpesvirus-1 and -4 (EHV-1 and EHV-4) was developed using polymerase chain reaction (PCR). Primers for PCR were designed from aligned nucleotide sequences of glycoprotein B genes of EHV-1 and EHV-4 to amplify specific regions for EHV-1 or EHV-4 or a common region of both viruses. By using type specific primer mixture, amplified fragments were identified as EHV-1 or EHV-4 in a one-step reaction. We have applied this technique on specimens from aborted fetuses. The samples contained only EHV-1 and there was complete accordance between the results of PCR and virus isolation. Our PCR system could differentiate the two virus types rapidly in a one-step reaction.
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Affiliation(s)
- R Kirisawa
- Department of Veterinary Microbiology, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan
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48
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Rimstad E, Evensen O. The identification of equid herpesvirus 1 in paraffin-embedded tissues from aborted fetuses by polymerase chain reaction and immunohistochemistry. J Vet Diagn Invest 1993; 5:174-83. [PMID: 8389598 DOI: 10.1177/104063879300500206] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Paraffin-embedded organ samples from 28 aborted fetuses and three foals, partly archival and partly sampled in 1991, were examined by polymerase chain reaction (PCR) and immunohistochemistry for the presence of DNA and antigens, respectively, specific for equine herpesvirus 1 (EHV-1). Virologic examination had been performed on 23 of the aborted fetuses. DNA fragments specific for EHV-1 were identified by PCR, and EHV-1 antigens were identified in situ by immunohistochemistry, with an agreement between the methods of 94% (kappa = 0.85). Compared with virus isolation, PCR agreement was 87% (kappa 0.69), and IH agreement was 82% (kappa = 0.47). These results showed that there was moderate to almost perfect agreement among the different methods and that PCR and immunohistochemistry are powerful tools for the identification of EHV-1 in paraffin-embedded tissues. The techniques give more rapid results than virus isolation and also detect inactivated virus, which are not identified by standard virus isolation. These techniques also make retrospective studies possible.
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Affiliation(s)
- E Rimstad
- Department of Microbiology and Immunology, Norwegian College of Veterinary Medicine, Oslo
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Sinclair R, Binns MM, Chirnside ED, Mumford JA. Detection of antibodies against equine herpesvirus types 1 and 4 by using recombinant protein derived from an immunodominant region of glycoprotein B. J Clin Microbiol 1993; 31:265-71. [PMID: 8381809 PMCID: PMC262747 DOI: 10.1128/jcm.31.2.265-271.1993] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The N-terminal fragment comprising residues +1 to +50 (gB1-50) of equine herpesvirus type 1 (EHV-1) glycoprotein B was expressed as a glutathione S-transferase fusion protein in Escherichia coli. Recombinant gB1-50 (rgB1-50) was recognized in immunoblots by sera from rabbits immunized with EHV-1 and by convalescent-phase sera from horses with natural EHV-1 infections. An enzyme-linked immunosorbent assay (ELISA) for monitoring antibody levels against EHV-1 was developed by using rgB1-50, and its specificity was assessed with a panel of reference antisera against other equine viruses. A specific cross-reaction was detected with EHV-4, which was confirmed by inhibition ELISA. Convalescent-phase sera from horses with natural EHV-1 or EHV-4 infections possessed antibody titers against rgB1-50 ranging from 1:2,000 to 1:64,000, indicating the presence of an immunodominant antigenic site. The study demonstrated the potential application of rgB1-50 as a diagnostic antigen and highlights the glutathione S-transferase fusion system as a simple and effective method of producing purified milligram quantities of antigen.
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Affiliation(s)
- R Sinclair
- Department of Infectious Diseases, Animal Health Trust, Newmarket, Suffolk, England
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50
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Belák S, Ballagi-Pordány A. Application of the polymerase chain reaction (PCR) in veterinary diagnostic virology. Vet Res Commun 1993; 17:55-72. [PMID: 8396281 PMCID: PMC7089349 DOI: 10.1007/bf01839180] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/1993] [Indexed: 01/30/2023]
Abstract
The polymerase chain reaction has become an important diagnostic tool for the veterinary virologist. Conventional methods for detecting viral diseases can be laborious or ineffective. In many cases PCR can provide a rapid and accurate test. In this article we explain the basic principles of PCR and supply a reference list of its uses in diagnostic veterinary virology.
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Affiliation(s)
- S Belák
- Department of Virology, National Veterinary Institute, Uppsala, Sweden
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