Molecular insights into peste des petits ruminants virus identified in Bangladesh between 2008 and 2020.

An in-depth knowledge of the molecular evolution of the peste des petits ruminants virus (PPRV) is critical for the success of the current global eradication program. For this reason, a molecular evolutionary analysis of PPRVs circulating in Bangladesh over a decade (2008-2020) was performed. The complete genome sequencing of three PPRV isolates from 2008 (BD2), 2015 (BD12) and 2017 (BD17) as well as full length nucleocapsid (N), matrix (M) and fusion (F) gene sequencing of seven more samples from 2015 to 2020 was performed. Phylogenetic analysis classified all ten PPRVs from Bangladesh as members of lineage IV and showed that they were closely related to PPRV strains detected in China and Tibet during 2007-2008, and India during 2014-2018. Time scale Bayesian Maximum Clade Credibility (MCC) phylogenetic analysis of the three complete genomes revealed a mean Time to Most Recent Common Ancestor (TMRCA) of 2000. Comparative deduced amino acid residue analysis at various functional motifs of PPRVs related to virus structure and function, virulence and host adaptation, receptor binding sites and polymerase activity revealed conserved residues among the PPRVs from Bangladesh. In total sixteen epitopes were predicted from four immunogenic proteins i.e. N, M, F and haemagglutinin (H). Interestingly, the predicted epitopes from the N and M proteins shared conserved epitopes with two vaccine strains currently being used, indicating that the strains from Bangladesh could be potentially used as alternative local vaccines.