Genomic exploration light on multiple origin with potential parsimony-informative sites of the severe acute respiratory syndrome coronavirus 2 in Bangladesh

17, November 2020 | Bangladesh

Authors:

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new strain of beta coronavirus that has spread worldwide within a short period of time and has been responsible for the current COVID-19 pandemic. This novel virus shows high transmission and adaptability frequency into the host with rapid changes in genomic sequences. In this study, we analyzed the complete genome of 41 strains isolated in Bangladesh to understand the evolutionary route and genetic variations of this rapidly evolving virus. The phylogenetics, parsimony infor- mative sites and mutation analyses were performed using MEGA X, Multiple sequence alignment program (MAFFT), and Virus Pathogen Resource. The phylogenetic analysis of the studied genomes along with the reference genome suggested that the viral strains found in Bangladesh might be coming from multiple countries such as France, Germany, India, the USA, and Brazil. After entering into the country, intra-cluster and inter- cluster began to circulate in the 8 individual divisions of Bangladesh. We also identified 26 parsimony- informative sites along with the 9 most important sites for virus evolution. Genome-wide annotations revealed 256 mutations, of which 10 were novel (NSP3, RdRp, Spike) in Bangladeshi strains where I120F(NSP2), P323L (RdRp), D614G (Spike), R203K, G204R(N) are the most prominent. Most importantly, numerous mutations were flourishing in the N protein gene (67) followed by S (45), RdRp (38), NSP2 (34), NSP3 (20), and ORF8 (6) gene. Moreover, nucleotide deletion analysis found nine deletions throughout the genomes including in ORF7a (8), ORF8 (1) with one insertion (G) at 265 positions in only one genome. The underlying mechanism of disease severity, molecular evolution, and epidemiology lie in genomic sequences that are not fully understood yet. Identification of the evolutionary history, parsimony-informative sites and others genetic variations of this deadly virus will facilitate the development of new strategies to control the local transmission and provide deep insight in the identification of potential therapeutic targets for controlling COVID-19.