Identification of Novel Variant Strain of Infectious Bursal Disease Virus in Xueshan Chicken
Novel variant strains of infectious bursal disease virus(IBDV)have been spreading widely in China,posing a new threat to commercial broilers and layers. In the study,a local variety of Xueshan chicken with suspected atypical IBD was detected by RT-PCR,gene sequencing and sequence analysis were then conducted for the three isolates. The results showed that the disease was caused by novel variant strain of IBDV that belongs to A2dB1 genotype;in addition to the characteristic amino acids of variant strain,the unique amino acids of novel variant IBDV were also contained in the hypervariable region of VP2 encoding proteins of the three isolates. It was indicated that the novel variant IBDV could not be effectively controlled by some current commercial vaccines,as it has been spreading in local chicken in China.