摘要
Coronavirus disease 2019(COVID-19)is an infectious disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),declared as a pandemic due to its rapid spreadworldwide.In this study,we investigate the genetic diversity and genomic epidemiology of SARS-CoV-2,using 22 virus genome sequences reported by three different laboratories in Morocco till June 7,2020,as well as 40,366 virus genomes from all around the world.The SARSCoV-2 genomes from Moroccan patients revealed 62 mutations,of which 30weremis-sense mutations.Themutations Spike_D614G and NSP12_P323L were present in all the 22 analyzed sequences,followed by N_G204R and N_R203K,which occurred in 9 among the 22 sequences.The mutations NSP10_R134S,NSP15_D335N,NSP16_I169L,NSP3_L431H,NSP3_P1292L and Spike_V6F occurred once in Moroccan sequences,with no record in other sequences worldwide.Phylogenetic analyses revealed that Moroccan SARS-CoV-2 genomes included 9 viruses belonging to Clade 20A,9 to Clade 20B and 2 to Clade 20C,suggesting that the epidemic spread inMorocco did not display a predominant SARS-CoV-2 route.Therefore,multiple and unrelated introductions of SARS-CoV-2 into Morocco through different routes have occurred,giving rise to the diversity of virus genomes in the country.Further,in all probability,the SARS-CoV-2 circulated in a cryptic way inMorocco,starting fromJanuary 15,2020 before the first case was officially discovered on March 2,2020.
