Molecular Characterization of Budgerigar Fledgling Disease Virus SC-YB19, with an 18-Nucleotides Deletion, in China

Abstract Background: Budgerigar fledgling disease virus (BFDV) poses a serious threat to the Chinese psittacine industry, causing enormous economic losses. This study aims to reveal the etiological role of BFDV and evaluate the molecular characterization.Results: We report on BFDV, designated SC-YB19, which had an 18-nucleotide (nt) deletion in the enhancer region, corresponding to the sequence position 164–181 nt, when compared with other BFDV strains. Sequence analyses suggested that 19 nucleotide substitutions were identified with the domestic strains, APV7 and AF118150. Phylogenetic analysis indicated that SC-YB19, along with three domestic strains, formed a unique cluster, and were closely related to Polish isolates. Conclusion: Taken together, these results demonstrate that a BFDV genotype variation was co-circulating in China, and provide important insights on evolution of BFDV.