广西百色边境40例新冠病毒感染病例SARS-CoV-2分子特征

Molecular characterization of SARS-CoV-2 in 40 cases at the border of Baise,Guangxi

目的 通过分析广西百色边境地区新冠病毒感染病例的新冠病毒的分子特征及变异情况,评估变异株的传播力、致病力,为科学防控提供依据。方法 对2022年4月—2023年5月广西百色边境地区40例新冠病毒感染病例的新冠病毒全基因组序列的分子特征进行分析,通过序列比对和构建系统进化树,确定毒株型别,分析其遗传变异差异。结果 40条序列在Nextclade数据库上有27条分型属于22B、5条属于21L、4条属于22F、2条属于23A、1条属于22D、1条属于23B。在Pangolin数据库上处于Omicron变异株16个不同分支。与武汉参考株相比,核苷酸突变包括69~106个替换突变,其中BF.8分支发现ORF1a区有C13436T突变、XBB系列变异株的核苷酸在ORF1b区有G15451A突变,所有序列均在N区28881~28883这3个核苷酸位点上有突变。全部Omicron变异株在S区都有G339D、S371F、T376A、D405N、R408S及N440K、T478K、E484A突变。XBB分支均在其受体结合域中比BA.2、BA.5变异株多9个氨基酸突变(V83A、H146Q、 E180V、G252V、L368I、G446S、N460K、F490S)。结论 新冠病毒在传播过程中核苷酸突变可能导致核酸检测试剂盒的检测灵敏度降低,序列氨基酸突变的信息预示病毒正在向更稳定、传播速度更快,可逃逸抗体作用更多的方向进化成为新毒株,需实时追踪病毒变异变迁规律,为治疗疾病和防控提供科学依据。

Objective In order to provide scientific basis for prevention and control of sars-cov,the molecular characteristics and variation of SARS-CoV-2 were analyzed of infection in the border area of Baise,Guangxi.Methods The molecular characteristics of the whole genome sequences of 40 cases of SARS-CoV-2 infection in the border region of Baise,Guangxi from April 2022 to May 2023 were analyzed.The phylogenetic tree was constructed by sequence alignment to determine the virus strain types and analyze the genetic variation.Results In Nextclade database,27 of 40 sequences belonging to 22B,5 to 21L,4 to 22F,2 to 23A,1 to 22D,1 to 23B.There were 16 different branches of the Omicron variant in Pangolin database.Compared with Wuhan reference strain,the nucleotide mutations included 69-106 substitution mutations,among them,BF-8 branch found a C13436T mutation in ORF1a region,a G15451A mutation in ORF1b region in XBB mutants,and all the sequences had mutations in N region(28881-28883).All the Omicron mutants were found to be mutated in s region(G339D,S371F,T376A,D405N,R408S,N440K,T478K,E484A).XBB had 9 amino acid mutations(V83A,H146Q,E180V,G252V,L368I,G446S,N460K,F490S)in its receptor binding domain than BA.2 and BA.5 mutants.Conclusion The nucleotide mutation of SARS-CoV-2 might lead to the decrease of the detection sensitivity of the nucleic acid detection kit,the information of sequence amino acid mutation indicates that the virus was evolving into a new strain,which is more stable and can escape the effect of antibody more quickly,to provide scientific basis for disease treatment and prevention and control.