title: Genetic variation and dynamics of infections of equid herpesvirus 5 in individual horses.
abstract: Equid herpesvirus 5 (EHV-5) is related to the human Epstein-Barr virus (human herpesvirus 4) and has frequently been observed in equine populations worldwide. EHV-5 was previously assumed to be low to non-pathogenic; however, studies have also related the virus to the severe lung disease equine multinodular pulmonary fibrosis (EMPF). Genetic information of EHV-5 is scanty: the whole genome was recently described and only limited nucleotide sequences are available. In this study, samples were taken twice 1 year apart from eight healthy horses at the same professional training yard and samples from a ninth horse that was diagnosed with EMPF with samples taken pre- and post-mortem to analyse partial glycoprotein B (gB) gene of EHV-5 by using next-generation sequencing. The analysis resulted in 27 partial gB gene sequences, 11 unique sequence types and five amino acid sequences. These sequences could be classified within four genotypes (I-IV) of the EHV-5 gB gene based on the degree of similarity of the nucleotide and amino acid sequences, and in this work horses were shown to be identified with up to three different genotypes simultaneously. The observations showed a range of interactions between EHV-5 and the host over time, where the same virus persists in some horses, whereas others have a more dynamic infection pattern including strains from different genotypes. This study provides insight into the genetic variation and dynamics of EHV-5, and highlights that further work is needed to understand the EHV-5 interaction with its host.
authors.affiliation: Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Back
authors.affiliation: Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Ullman
authors.affiliation: Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Leijon
authors.affiliation: Department of Bacteriology, National Veterinary Institute, Uppsala, Sweden.
authors.forename: Robert
authors.initials: R
authors.lastname: Söderlund
authors.affiliation: Department of Veterinary Epidemiology and Public Health, University of Surrey, Guildford, UK.
authors.forename: Johanna
authors.initials: J
authors.lastname: Penell
authors.affiliation: Department of Disease Control and Epidemiology, National Veterinary Institute, Uppsala, Sweden.
authors.forename: Karl
authors.initials: K
authors.lastname: Ståhl
authors.affiliation: Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: John
authors.initials: J
authors.lastname: Pringle
authors.affiliation: Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden.|Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Valarcher
mesh_terms: D000818:Animals; D002353:Carrier State / Q000662:veterinary* / Q000821:virology; D016000:Cluster Analysis; D060085:Coinfection / Q000662:veterinary / Q000821:virology; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006564:Herpesviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D006566:Herpesviridae Infections / Q000662:veterinary* / Q000821:virology; D006734:Horse Diseases / Q000821:virology*; D006736:Horses; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D004279:DNA, Viral