Prevalence of equine herpesvirus type 2 (EHV-2) DNA in ocular swabs and its cell tropism in equine conjunctiva.
Abstract: Equine herpes virus 2 (EHV-2), a gamma(2)-herpesvirus, is common in horses of all ages. Its role as a primary pathogen is unclear but there is an association between EHV-2, respiratory disease and keratoconjunctivitis. The purpose of this study was to gain more information on the prevalence of EHV-2 DNA in conjunctival swabs from horses with and without ocular disease and to define the anatomical site and cell type harbouring viral genome or antigen. By polymerase chain reaction (PCR) 22 out of 77 (28.6%) ocular swabs of clinically healthy and only 4 out of 48 (8.3%) samples from diseased horses were positive. To define the main virus reservoir ocular tissue from 13 randomly selected horses without pathological evidence of ocular disease were analysed by nested PCR. In two horses optic nerve, lacrimal gland and conjunctiva, in further two cases lacrimal gland and conjunctiva and in four horses the conjunctiva only were EHV-2 PCR positive. For specifying the target cell we focused on conjunctivae and selected 3 out of 15 clinically healthy slaughterhouse horses positive for EHV-2 by PCR. In situ hybridisation on sections of these paraffin embedded conjunctivae localized viral genome in histiocyte-like cells of the submucosa. Immunohistochemical staining with an EHV-2 or S100 specific polyclonal antiserum demonstrated that Langerhans cells were co-localized in the same region of the sample section where virus positive cells were detected. Furthermore, we concluded that detection of viral antigen revealed a productive virus infection.
Publication Date: 2006-08-11 PubMed ID: 16996233DOI: 10.1016/j.vetmic.2006.07.024Google Scholar: Lookup
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- Journal Article
Summary
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This study examines the prevalence of Equine Herpes Virus 2 (EHV-2) in ocular swabs from horses, both with and without ocular disease. It reveals that 28.6% of healthy horses and only 8.3% of diseased horses tested positive for the virus, and that the virus primarily exists in conjunctiva and lacrimal glands.
Virus Prevalence and Detection
- The researchers carried out their study on Equine Herpes Virus 2 (EHV-2), a common virus in horses that is typically associated with respiratory disease and keratoconjunctivitis.
- The study was carried out using polymerase chain reaction (PCR), a method used to amplify small segments of DNA, in order to gain more insight into the prevalence of EHV-2 DNA in horses.
- The results indicated that 22 out of 77 (28.6%) ocular or eye swabs from clinically healthy horses tested positive for EHV-2. On the other hand, only 4 out of 48 samples (8.3%) picked up the virus in horses with eye diseases.
Anatomical Site and Cell Type of Virus
- Besides determining the prevalence of the virus, the study also aimed to figure out the anatomical site and cell type which harbors the viral genome or antigen.
- Ocular tissue samples from 13 randomly selected horses were analysed. PCR detected EHV-2 in the optic nerve, lacrimal gland and conjunctiva in two horses. In two other cases, the virus showed up in the lacrimal gland and conjunctiva. Four horses had the virus in their conjunctiva only.
Target Cell and Virus Infection
- To specify the target cell, the researchers focused on conjunctiva tissues from 15 clinically healthy horses, 3 of which tested positive for EHV-2.
- Using a technique called in situ hybridisation, the scientists located the viral genome in histiocyte-like cells, cells that ingest foreign matter, in the submucosa.
- In addition, immunohistochemical staining with an EHV-2 or S100 specific polyclonal antiserum confirmed that Langerhans cells, specialized immune cells, were located in the same region where virus positive cells were detected.
- From these findings, it was concluded that the detection of viral antigen showed a productive virus infection.
Cite This Article
APA
Borchers K, Ebert M, Fetsch A, Hammond T, Sterner-Kock A.
(2006).
Prevalence of equine herpesvirus type 2 (EHV-2) DNA in ocular swabs and its cell tropism in equine conjunctiva.
Vet Microbiol, 118(3-4), 260-266.
https://doi.org/10.1016/j.vetmic.2006.07.024 Publication
Researcher Affiliations
- Institute of Virology, Faculty of Veterinary Medicine, Free University of Berlin, Königin-Luise-Str 49, Berlin, Germany. borchers@zedat.fu-berlin.de
MeSH Terms
- Animals
- Antigens, Viral / isolation & purification
- Conjunctivitis, Viral / epidemiology
- Conjunctivitis, Viral / veterinary
- Conjunctivitis, Viral / virology
- DNA, Viral / isolation & purification
- Herpesviridae Infections / epidemiology
- Herpesviridae Infections / veterinary
- Herpesviridae Infections / virology
- Horse Diseases / epidemiology
- Horse Diseases / virology
- Horses
- Immunohistochemistry / veterinary
- Langerhans Cells / virology
- Polymerase Chain Reaction / methods
- Polymerase Chain Reaction / veterinary
- Prevalence
- Rhadinovirus / genetics
- Rhadinovirus / isolation & purification
- Tumor Virus Infections / epidemiology
- Tumor Virus Infections / veterinary
- Tumor Virus Infections / virology
Citations
This article has been cited 11 times.- Miglinci L, Reicher P, Nell B, Koch M, Jindra C, Brandt S. Detection of Equine Papillomaviruses and Gamma-Herpesviruses in Equine Squamous Cell Carcinoma. Pathogens 2023 Jan 23;12(2).
- Onasanya AE, El-Hage C, Diaz-Méndez A, Vaz PK, Legione AR, Browning GF, Devlin JM, Hartley CA. Whole genome sequence analysis of equid gammaherpesvirus -2 field isolates reveals high levels of genomic diversity and recombination. BMC Genomics 2022 Aug 30;23(1):622.
- Stasiak K, Dunowska M, Rola J. Kinetics of the Equid Herpesvirus 2 and 5 Infections among Mares and Foals from Three Polish National Studs. Viruses 2022 Mar 29;14(4).
- El-Hage C, Mekuria Z, Dynon K, Hartley C, McBride K, Gilkerson J. Association of Equine Herpesvirus 5 with Mild Respiratory Disease in a Survey of EHV1, -2, -4 and -5 in 407 Australian Horses. Animals (Basel) 2021 Nov 30;11(12).
- Dayaram A, Seeber PA, Greenwood AD. Environmental Detection and Potential Transmission of Equine Herpesviruses. Pathogens 2021 Apr 1;10(4).
- Thorsteinsdóttir L, Jónsdóttir S, Stefánsdóttir SB, Andrésdóttir V, Wagner B, Marti E, Torsteinsdóttir S, Svansson V. The effect of maternal immunity on the equine gammaherpesvirus type 2 and 5 viral load and antibody response. PLoS One 2019;14(6):e0218576.
- Azab W, Bedair S, Abdelgawad A, Eschke K, Farag GK, Abdel-Raheim A, Greenwood AD, Osterrieder N, Ali AAH. Detection of equid herpesviruses among different Arabian horse populations in Egypt. Vet Med Sci 2019 Aug;5(3):361-371.
- Marenzoni ML, Stefanetti V, Danzetta ML, Timoney PJ. Gammaherpesvirus infections in equids: a review. Vet Med (Auckl) 2015;6:91-101.
- Stasiak K, Dunowska M, Rola J. Prevalence and sequence analysis of equid herpesviruses from the respiratory tract of Polish horses. Virol J 2018 Jul 11;15(1):106.
- Pennington MR, Ledbetter EC, Van de Walle GR. New Paradigms for the Study of Ocular Alphaherpesvirus Infections: Insights into the Use of Non-Traditional Host Model Systems. Viruses 2017 Nov 18;9(11).
- Rushton JO, Kolodziejek J, Tichy A, Nowotny N, Nell B. Clinical course of ophthalmic findings and potential influence factors of herpesvirus infections: 18 month follow-up of a closed herd of lipizzaners. PLoS One 2013;8(11):e79888.
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