摘要
目的:分析2022—2023监测年度昆明市甲型H1N1流感毒株的血凝素(hemagglutinin,HA)及神经氨酸酶(neuraminidase,NA)基因特征。方法:选取2022年4月—2023年3月从昆明市哨点医院监测病例以及暴发疫情病例中分离得到的15株甲型H1N1流感毒株进行测序,使用MAFFT version 7、MegAlign与MEGA 11进行序列比对、同源性分析、系统进化树构建与氨基酸变异分析。结果:2022—2023监测年度昆明市分离得到的14株毒株位于6B.1A.5a.2a分支,A/Kunming/284/2023位于6B.1A.5a.2a.1分支,均与位于6B.1A.5a.2分支的2022—2023年度北半球疫苗株A/Wisconsin/588/2019偏离。与疫苗株HA基因相比:14株毒株均在Sb区发生A186T、Q189E变异,可能导致疫苗的保护性下降,A/Kunming/284/2023的P137S、K142R变异位于Ca区,A186T、Q189E变异位于Sb区,与2株来源于泰国毒株的变异位点相同,从分子水平显示了免疫逃逸的可能;15株毒株均在190螺旋发生Q189E变异,在220环发生E224A变异,可能导致病毒的致病性发生改变。与疫苗株NA基因相比:在抗原位点区域,14株毒株发生了S200N变异,1株毒株发生了S339L变异,可能导致NA诱导抗体的保护作用降低。结论:昆明市应加强流感监测,及时发现新的变异株,有助于防止外来输入,对流感暴发作出预警。
Objective To analyze the genetic characteristics of hemagglutinin(HA)and neuraminidase(NA)of influenza A(H1N1)pdm09 viruses in Kunming during the 2022-2023 influenza season.MethodsA total of 15 strains of A(H1N1)pdm09 influenza virus isolated from sentinel hospital surveillance and from outbreaks from April 2022 to March 2023 in Kunming were chosen for sequencing.The genetic analysis,which included sequence alignment,homology analysis,construction of phylogenetic tree and amino-acid mutations analysis,was carried out using MAFFT version 7,MegAlign and MEGA 11.ResultsFourteen strains isolated during the 2022-2023 influenza season in Kunming belong to clade 6B.1A.5a.2a,and A/Kunming/284/2023 belonged to clade 6B.1A.5a.2a.1.They all diverged from the northern hemisphere vaccine strain A/Wisconsin/588/2019 in clade 6B.1A.5a.2 recommended by WHO during the 2022-2023 influenza season.Comparing with the HA of the vaccine strain:A186T and Q189E,which might cause the reduction of vaccine protection,were identified in Sb of 14 strains;P137S,K142R in Ca and A186T,Q189E in Sb were identified in A/Kunming/284/2023 and two strains isolated from Thailand.The four mutations at tow antigenic sites identified immune escape at the molecular level.Q189E in the 190-helix and E224A in the 220-loop,which might change the pathogenicity of A(H1N1)pdm09 viruses,were identified in 15 strains.Comparing with NA of the vaccine strain:S200N in 14 strains and S339L in 1 strain were identified in antigenic sites.The two mutations might reduce the protection of antibodies induced by NA.ConclusionStrengthening influenza surveillance and timely detecting new variants in Kunming contributes to preventing the importation of foreign strains and issuing early warnings for influenza outbreaks.
作者
简千棋
杨瑶
马丽波
朱心
侯敏
刘如锦
李文龙
Jian Qianqi;Yang Yao;Ma Libo;Zhu Xin;Hou Min;Liu Rujin;Li Wenlong(Microbiology Laboratory,Kunming Center for Disease Control and Prevention,Kunming 650228,China)
出处
《中华微生物学和免疫学杂志》
北大核心
2025年第10期832-838,共7页
Chinese Journal of Microbiology and Immunology
基金
昆明市卫生科技人才培养项目暨“十百千”工程[2019-Sw(后备)-48]。
