Molecular characterization and phylogenetic analysis of VIIl sub-genotype of avian orthoavulavirus 1 isolated from Eurasian magpie (Pica pica).

Abstract

Newcastle disease (ND) has been categorized as a highly contagious viral disease, remaining as a constant threat to both wild birds and commercial chickens. In this study, we recovered and characterized the avian orthoavulavirus 1 (AOaV-1) strain, nominated as EM1, from the Eurasian magpie (Pica pica). The nucleotide and amino acid sequence of the fusion protein (F protein) of EM1 were determined and its phylogenetic relationship was investigated with well-characterized AOaV-1 genotypes, which originated from wild bird species and chickens around the world. Phylogenetic analysis and deduced amino acid sequences of the F gene revealed that EM1 virus belonged to VIIl sub-genotype viruses with the characteristic multibasic amino acid sequences associated with the velogenic motif as 112RRQKRF117 at the cleavage site of its precursor fusion protein. EM1 shared a high level of similarity to the other virus sub-genotypes in nucleotide and amino acid sequences of F protein. Furthermore, the evolutionary difference between the studied virus and viruses belonging to the VIIl sub-genotype indicated that a close relatedness and the possibility of a common origin. These results show that the virulent AOaV-1 of sub-genotype VIIl is circulating continuously in Iran, and is disseminating among wild and domestic bird species that can cause bidirectional spillover infection. Therefore, further epidemiological studies can be beneficial in the assessment of the evolution of AOaV-1 in its hosts and will help us to be well-equipped in facing the emergence of new sub-genotypes of this virus.