Characteristics of rabies street virus strain BD06 for challenge test in dogs

Objective To analyze the specificity of rabies street virus strain BD06 and evaluate its effect in challenge test in dogs. Methods BD06 was subcultured to passage 10 in brains of Beagle dogs,and tested for adventitious agents including foreign viruses such as dog distemper virus,parvovirus,coronavirus as well as adenovirus types Ⅰ and Ⅱ, mycoplasma and sterility according to the requirements in Chinese Veterinary Pharmacopoeia(Volume Ⅲ,2010 edition). Total RNA was extracted from the brain tissue of dogs, in which the virus was subcultured to passage 10, for amplification by RT-PCR and sequencing. The virus was subcultured in the brains of mice and determined for MICLD50. Dogs were challenged i. m. with the mouse brain suspensions at dosages of 2 × 104,5 × 104和 10 × 104MICLD50 / ml in behind limbs and masseter separately. Results No foreign viruses,mycoplasma or bacteria were observed in BD06 strain after subculture in dog brain to passage 10,while the gene sequence showed no change. The MICLD 50 of the strain after subculture in mouse brain for one passage reached 105. 32/ ml. The challenge test in dogs with the strain at a dosage of 5 × 104MICLD50/ ml by injection in masseter showed satisfactory effect. Conclusion Rabies virus strain BD06 was simple to be subcultured and highly pathogenic to dogs,which might be used as a candidate for challenge test in dogs.