title: Comparative study of clinical courses, gross lesions, acute phase response and coagulation disorders in sheep inoculated with bluetongue virus serotype 1 and 8.
abstract: Bluetongue virus serotypes 1 (BTV-1) and 8 (BTV-8) have been described as the most prevalent in Europe during recent outbreaks displaying intense virulence, sheep being among the most severely affected livestock species. However, BTV pathogenesis is still unclear. This study sought to elucidate differences in the pathogenetic mechanisms of BTV-1 and -8 in sheep. For this purpose, a time-course study was carried out, with sequential sacrifices in order to relate pathological lesions to changes in a range of virological and serological parameters. A greater virulence of BTV-1 was probed. BTV-1 infected sheep showed a longer clinical course, with a significant increase of clinical signs and more severe gross lesions than BTV-8 infected sheep. These differences appear not to be attributable to greater virus replication, suggesting viral loads did not influence in the pathogenicity of these serotypes. While both groups displayed an early, intense antibody response, they still developed clinical signs and lesions characteristic of bluetongue, indicating a lack of correlation between antibody levels and protection against the disease. Both acute phase response (APR) and thrombocytopenia induced by BTV-1 in sheep were more intense. Furthermore, an association between acute phase proteins (APPs) concentrations and the evolution of clinical signs and gross lesions was also observed, suggesting the existence of a direct link between the pathogenicity of BTV serotypes, the severity of vascular lesions and the serum concentrations of APPs. To our knowledge, this is the first verification of a measurable APR in sheep with both experimental and naturally occurring bluetongue.
authors.affiliation: Department of Comparative Pathology, Veterinary Faculty, University of Córdoba-Agrifood Excellence International Campus (ceiA3), Edificio Sanidad Animal, Campus de Rabanales, 14014 Córdoba, Spain. an2sacop@uco.es
authors.forename: P J
authors.initials: PJ
authors.lastname: Sánchez-Cordón
authors.forename: F J
authors.initials: FJ
authors.lastname: Pleguezuelos
authors.forename: A C
authors.initials: AC
authors.lastname: Pérez de Diego
authors.forename: J C
authors.initials: JC
authors.lastname: Gómez-Villamandos
authors.forename: J M
authors.initials: JM
authors.lastname: Sánchez-Vizcaíno
authors.forename: J J
authors.initials: JJ
authors.lastname: Cerón
authors.forename: F
authors.initials: F
authors.lastname: Tecles
authors.forename: B
authors.initials: B
authors.lastname: Garfia
authors.forename: M
authors.initials: M
authors.lastname: Pedrera
mesh_terms: D000209:Acute-Phase Proteins / Q000276:immunology; D000210:Acute-Phase Reaction / Q000662:veterinary* / Q000821:virology; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D001777:Blood Coagulation; D001819:Bluetongue / Q000097:blood / Q000276:immunology / Q000473:pathology* / Q000821:virology*; D001820:Bluetongue virus / Q000145:classification / Q000276:immunology / Q000472:pathogenicity* / Q000502:physiology; D012756:Sheep; D014774:Virulence
chemical_list: D000209:Acute-Phase Proteins; D000914:Antibodies, Viral
keywords: Acute phase response; Bluetongue virus serotypes 1 and 8; Clinical signs; Coagulation disorders; Gross lesions; Sheep