自然发生SARS病例的病毒基因溯源分析

Source Tracing of the Spontaneous SARS Case Viral Gene Sequence

目的SARS病毒基因分型特别有助于病毒的溯源和控制。方法对GenBank登记的SARS病毒和SARS样病毒等有关病毒序列进行了分析,以牛冠状病毒,鸟冠状病毒和冠状病毒科的Breda病毒为外组,构建了SARS病毒和SARS样病毒系统进化树,并进行单核苷酸变异分析。结果发现两次SARS自然流行的病毒可分为两个明显不同的聚类;首次把第二次流行时从人类中分离的SARS病毒和从果子狸等动物中分离的SARS样病毒分为H和P基因型;H/P型的主要依据在病毒的非结构多蛋白基因序列而不是Spike基因序列。结论两次SARS自然流行的病毒可能以不同的特性感染人类而不是简单的重复。结合流行病学资料,对第二次流行时的SARS病毒进行分子水平的溯源分析,前两例指标患者的病毒和果子狸等动物的SARS样病毒基因序列的直接关系仍不明确。并对SARS病毒的原型、蝙蝠中的冠状病毒牵连等提出了一些新的观点。

Objective To trace the virus source and control blows by SAILS virus genotyping. Methods The sequences of SARS-Cov and SARS-like virus from GenBank were download. Taking the bovine coronavirus, the avian infectious bronchitis virus and the breda virus as the autgroup, SAILS virus and SARS-like virus system evolution tree was constructed, and the single nucleotide variation was investigated systematically. Results The viruses from two SAILS nature epideruics may obviously be divided into two different clusters. SAILS virus from humanity in secondary epidemic and SARS-like vires from animals such as himalayan pahn civet were divided into H and P genotypes for the first time. The H/P genotyping mainly based on virus＇s genome sequence rather than the spike gene sequence. Conclusion The viruses of two SAILS nature epidemics possibly infect the hmnnity by different eharaeteristis, and the secondary epidemic was not a simple repetition of the first one. Source-tracing analysis of SAILS virus for the secondary epidenfie was adopted on molecular level. No clear relations of the gene sequences between the first two index patients＇ viruses and SARS-like viruses from animals were found.Some new views about SARS-CoV＇s prototype and the relation between SARS virus and bat＇ s eoronavirus were proposed.