A novel genotype of beak and feather disease virus in budgerigars (Melopsittacus undulatus).

Beak and feather disease virus (BFDV) is a causative agent for psittacine beak and feather disease (PBFD), which shows a characteristic feather disorder in psittacine birds. Nineteen budgerigars, which were clinically suspected to have PBFD, were examined by two polymerase chain reactions (PCR), which target each of open reading frames (ORFs) V1 and C1. All of the 19 samples were detected BFDV by the PCR targeting ORF C1, whereas only two of them were detected by the PCR targeting ORF V1. It was assumed that BFDV derived from budgerigar (budgerigar BFDV) has two genotypes, which are tentatively classified as budgerigar BFDV genotype 1 and genotype 2 by the PCR amplification patterns. Whole genome sequences of six budgerigar BFDVs were determined to reveal the existence of two genotypes. In the phylogenic analysis, six budgerigar BFDV sequences formed a unique group branched from the other 23 published BFDV sequences. The budgerigar BFDV genotype 1 and genotype 2 were also segregated each other, and budgerigar BFDV genotype 2 was particularly distantly related with the other BFDVs. These results suggest budgerigar BFDV is a unique in the known BFDVs and is divided into two genotypes.