A Bovine Viral Diarrhea Virus Type 1c Strain in China: Isolation, Identification, and Assessment of Pathogenicity in Rabbits.

Bovine viral diarrhea virus (BVDV) is an important animal pathogen and has a negative economic impact on cattle industries worldwide. In this study, the BVDV strain named BJ175170 was detected, isolated, and identified from cattle in Beijing, China, during herd screening by BVDV antigen-ELISA and indirect immunofluorescence assay (IFA). To investigate its genomic features, the characteristic 5'UTR region of the isolates were sequenced and BLAST analyzed. BVDV BJ175170 belongs to the BVDV-1c subtype, which differs from the Beijing prevalent BVDV strains. The BVDV particles were further observed by transmission electron microscopy (TEM). To evaluate the virulence of the BVDV BJ175170, the BVDV seronegative rabbits were intraperitoneally inoculated with the virus suspension. Blood samples were analyzed for changes in leukocyte number and antibody titer, and tissue samples were taken for histopathology analysis. These data confirmed again that rabbits could act as the reservoir of BVDV, which poses a small but non-zero risk of re-infection for BVDV-free cattle herds. To our knowledge, this is the first report of pathological changes in rabbits after exposure to BVDV-1c subtype, which could act as experimental reference. Meanwhile, the results of this study indicate that rabbits could act as a potential model for studying the mechanism of BVDV in vivo.