RESUMEN

This study was aimed at understanding the genome-wide characterization and variations for three imported novel coronavirus(SARS-CoV-2)strains from different sources in the same period in Jinan at the viral genome level,to provide a sci-entific basis for further improving the prevention and control of COVID-19 outbreaks at Jinan port.We selected nasal and pha-ryngeal swab samples from three cases of imported asymptomatic COVID-19infectionat Jinan port;performed second-genera-tion whole-genome sequencing;and analyzed the variant loci and homology withvarious bioinformatics software.The whole ge-nome sequence of SARS-CoV-2 was successfully obtained from three samples of asymptomatic infected cases,and had full lengths ranging from 29 835 bp to 29 844 bp.Pangolin typing results indicated that the genotypes of the three samples were O-micron BQ.1,BQ.1.1,and BQ.1.12.Compared with the original Wuhan strain,the three samples produced mutations at 77,80,and 78 base sites,respectively,involving 60-63 non-synonymous mutations,mainly in the S and ORF1ab genes.Omicron BQ.1 is an imported variant of the SARS-CoV-2 virus and was detected for the first time at Jinan port.From a molecular biolo-gy perspective,this study provides a theoretical basis for the source tracing and prevention and control of COVID-19 at theport.