ABSTRACT Human coronavirus NL63 (HCoV-NL63) is primarily associated with common cold in children, elderly and immunocompromised individuals. Outbreaks caused by HCoV-NL63 are rare. Here we report a cluster of HCoV-NL63 cases with severe lower respiratory tract infection that arose in Guangzhou, China, in 2018. Twenty-three hospitalized children were confirmed to be HCoV-NL63 positive, and most of whom were hospitalized with severe pneumonia or acute bronchitis. Whole genomes of HCoV-NL63 were obtained using next-generation sequencing. Phylogenetic and single amino acid polymorphism analyses showed that this outbreak was associated with two subgenotypes (C3 and B) of HCoV-NL63. Half of patients were identified to be related to a new subgenotype C3. One unique amino acid mutation at I507 L in spike protein receptor binding domain (RBD) was detected, which segregated this subgenotype C3 from other known subgenotypes. Pseudotyped virus bearing the I507 L mutation in RBD showed enhanced entry into host cells as compared to the prototype virus. This study proved that HCoV-NL63 was undergoing continuous mutation and has the potential to cause severe lower respiratory disease in humans.
【저자키워드】 whole-genome sequencing, Pneumonia, viral entry, Phylogenetic analysis, human coronavirus NL63, new subgenotype, 【초록키워드】 coronavirus, Mutation, Hospitalized, children, Human, Genome, Infection, polymorphism, virus, Spike protein, Receptor binding domain, outbreak, RBD, humans, Next-generation sequencing, Respiratory disease, Patient, Cluster, NL63, common cold, severe pneumonia, HCoV-NL63, Amino acid, Analysis, Lower respiratory tract, host cell, immunocompromised individuals, bronchitis, positive, prototype virus, caused, Guangzhou, China, unique, 【제목키워드】 coronavirus, Infection, China, NL63, Lower respiratory tract,