title: Genetic heterogeneity and variation in viral load during equid herpesvirus-2 infection of foals.
abstract: Equine herpesvirus-2 (EHV-2) infection has been implicated as a cause of a variety of clinical disorders in young horses, including upper respiratory tract disease, generalized malaise, fever, pharyngeal lymphoid hyperplasia, and lymphadenopathy. Considerable sequence heterogeneity has been demonstrated previously among EHV-2 strains, and individual horses can be concurrently infected with more than one virus strain. In this study, the temporal variation of the viral load and genomic diversity of the glycoprotein B (gB) gene of EHV-2 in the nasal secretions of a cohort of foals was characterized during the first 5 months of life. The viral load in nasal secretions of foals peaked when the foals were approximately 3 months old, and there was notable genetic heterogeneity of the gB gene, both among foals and within individuals. Furthermore, there was evidence of positive selection of EHV-2 variants with unique amino acid sequences at specific sites of gB.
authors.affiliation: Equine Viral Disease Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Brault
authors.forename: Brian H
authors.initials: BH
authors.lastname: Bird
authors.forename: Udeni B R
authors.initials: UB
authors.lastname: Balasuriya
authors.forename: N James
authors.initials: NJ
authors.lastname: MacLachlan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018740:Genetic Heterogeneity; D014644:Genetic Variation; D006566:Herpesviridae Infections / Q000662:veterinary* / Q000821:virology; D006734:Horse Diseases / Q000821:virology*; D006736:Horses; D008969:Molecular Sequence Data; D010802:Phylogeny; D018144:Rhadinovirus / Q000145:classification / Q000235:genetics*; D016415:Sequence Alignment; D014759:Viral Envelope Proteins / Q000235:genetics; D019562:Viral Load / Q000662:veterinary
chemical_list: D014759:Viral Envelope Proteins; C040495:glycoprotein B, Simplexvirus