Comparative pathogenicity of bovine herpesvirus 1 (BHV-1) subtypes 1 (BHV-1.1) and 2a (BHV-1.2a)

Pesquisa Veterinária Brasileira

Weiblen, Rudi²  Esteves, Paulo Augusto³  Roehe, Paulo Michel³  Lima, Marcelo de²  Flores, Eduardo Furtado²  Driemeier, David¹  Franco, Ana Cláudia³  Chiminazzo, Cláudio³  Spilki, Fernando Rosado³ 

[1] Universidade Federal do Rio Grande do Sul;Universidade Federal de Santa Maria, Santa Maria;Fepagro Saúde Animal, Eldorado do Sul, Brazil

关键词: Infectious bovine rhinotracheitis;    IBR;    BHV-1.1;    BHV-1.2a;    subtypes;    pathogenicity.;   

DOI  :  10.1590/S0100-736X2004000100010

来源: Colegio Brasileiro de Patologia Animal-CBPA

【 摘 要 】

The study aimed to examine the capacity of two bovine herpesvirus type 1 (BHV-1) isolates of different subtypes (EVI 123/96, BHV-1.1; SV265/98, BHV-1.2a) to induce respiratory disease in calves. These two isolates are representative of the BHV-1 subtypes prevalent in Brazil. Viral subtypes were confirmed by monoclonal antibody analysis and by restriction enzyme digestion of viral genomes. The viruses were inoculated intranasally into seven 3 months old calves (four with BHV-1.1, three with BHV-1.2a). Three other calves of identical age and condition were kept as uninfected controls. In both groups of infected calves, the clinical signs observed were consistent with typical infectious bovine rhinothracheitis (IBR), including pyrexia, apathy, anorexia, nasal and ocular mucopurulent discharges, erosions on the nasal mucosa, conjunctivitis, lachrymation, redness of nasal mucosa, dyspnoea, coughing, tracheal stridor and enlargement of retropharingeal, submandibular and cervical lymphnodes. No significant differences were observed between the clinical scores attributed to both groups. Virus shedding in nasal and ocular secretions were also similar, apart from a significant difference in nasal virus shedding on day 1 to 3 post-inoculation, which was higher for BHV-1.1 than for BHV-1.2a. Following corticosteroid induced reactivation of the latent infection, recrudescence of clinical signs was also observed, with no significant differences on both groups. It was concluded that both subtypes BHV-1.1 and BHV-1.2a were able to induce clinically undistinguishable respiratory disease in calves, either subsequent to a primary infection or following reactivation.Index

【 授权许可】

CC BY-NC