Molecular evolution of human coronavirus in Guangzhou from 2010 to 2012

Abstract

Objective To investigate the molecular evolution characteristics of human coronavirus (HCoV) subtypes in patients with fever and respiratory tract infection in Guangzhou from 2010 to 2012. Methods Partial fragments of NP, RdRp and S genes of HCoV-OC43, HCoV-229E and HCoV-NL63 positive samples were amplified by RT-PCR and sequencing. Bioinformatics software, including Bio-edit, Mega4.0 and Clustal1.83 were used for comparison and analysis of NP, RDRp and S gene sequences. Molecular evolutionary tree of different gene regions of HCoV-OC43, HCoV-229E and HCoV-NL63 were built. Results No remarkable variation or recombinant strain of HCoV-OC43, HCoV-229E and HCoV-NL63 was found in Guangzhou during 2010—2012. The HCoV-OC43 substrains were genetically closest to the strains found in Belgium and Hong Kong (GenBank accession number JN129834 and AY903460). HCoV-229E substrains were genetically closest to those found in Amsterdam (GenBank accession number JX503060) and HCoV-NL63 most genetically close to those in Amsterdam and Beijing (GenBank accession number JX104161 and DQ445911). The NP and RDRp genes of all subtypes were highly conserved, while S gene was more variable. Conclusions There were at least 3 substrains of HCoV-OC43, HCoV-229E and HCoV-NL63 epidemic in Guangzhou during 2010—2012, and no remarkable variation or recombinant viral strain was found. The NP and RDRp genes of all subtypes were highly conserved and can be used in virus detection, while S gene was more variable and suitable for phylogenetic and variation study. Key words: Respiratory tract infection; Human coronavirus OC43; Human coronavirus 229E; Human coronavirus NL63; Molecular evolution