Genetic characterization of influenza A(H1N1)pdm09 virus in Sanmenxia,Henan,2016-2023
Objective To delineate the evolutionary characteristics,antigenic and receptor binding site variations,and genetic progression of hemagglutinin(HA)and neuraminidase(NA)genes of the influenza virus A(H1N1)pdm09 in Sanmenxia City,Henan Province from 2016 to 2023.Methods A total of 24 A(H1N1)pdm09 influenza virus strains isolated from Sanmenxia City between 2016 and 2023 were selected.Following nucleic acid extraction,the complete influenza virus genome was subjected to second-generation sequencing.Bioinformatics software was applied to analyze the HA and NA gene characteristics and to construct a phylogenetic tree.Results A progressive decrease in HA,NA nucleotide and amino acid homology was observed from 2016 to 2023 relative to the A/California/07/2009 reference strain.Despite this decrease,homology with the annual recommended vaccine strains remained above 96％,with strains classified under the 6B.1 and 6B.2 branches,evolving into sub branches such as 6B.1A,6B.1A.5,6B.1A.7.,HA1 protein exhibited 60 amino acid mutations,with 11 mutation sites in the antigenic determinant cluster,while the NA protein showed 45 amino acid mutations across 13 antigenic determinants and drug binding sites comparing with reference strain.Among 2023 strains,eight new mutation sites were identified on HA,including mutations of A186T and Q189E located within the HA antigen determinant cluster.Two novel mutation sites,V453M and K469N,emerged in the NA protein.An additional glycosylation site at position 162(162NQSY or 162NQT)in the HA1 protein's Sa antigen determinant cluster was found in 23 strains,within and all strains presented anextra glycosylation site at position 42(NQS)in the NA protein.Conclusions The HA and NA genes of the A(H1N1)pdm09 influenza virus isolated in Sanmenxia City have undergone continu-ous amino acid mutations and an increase in glycosylation sites.These findings highlight the necessity to enhance the surveil-lance of influenza virus types and mutations.
Influenza virusHemagglutininNeuraminidaseAntigenic determinantMutation sitePhylogenetic tree
NETL
NSTL
万方数据
