摘要
目的为了解在同一地区内同期发生的2起流行性感冒(流感)爆发中的病毒是否为同一性状以及病毒间抗原性的差异。方法从狗肾传代细胞(MDCK)分离的流感毒株提取病毒核糖核酸(RNA)后,经逆转录-聚合酶链反应(RT-PCR),扩增后的产物纯化后进行序列测定。结果2起爆发所分离的病毒经血清学鉴定均为甲3型流感病毒,核苷酸序列测定发现,引起2起爆发的甲3型流感病毒的抗原间有较大的差异。两者因10个核苷酸序列有差异而造成5个氨基酸被替换,其中3个发生在重要的抗原位点上,同源性98.5%。显示引起2起爆发的流感病毒并非来自同一毒株。其中1起爆发的毒株与2003年曾在宁波市流行的甲3型流感毒株同源性相接近,似是原先流行的毒株引起的爆发。而另1起爆发的毒株则与2003年流行的毒株同源性相差较远,并与当地后来流行的甲3型流感病毒的同源性更近,显然这是一起由流感病毒抗原性发生变异后的毒株引起的爆发。结论在同一地区同期流行的甲3型流感病毒的毒株并不一定为同一性状,抗原发生变异后的流感病毒可引起爆发,原先流行的毒株只要还有易感人群仍可造成爆发。
Objective To understand the antigen difference of influenza A （H3N2） viruses isolated in two outbreaks in the same area simultaneouly. Methods Viral RNA was extracted from the viruses isolated in MDCK and transcribed into cDNA by reverse transcriptase and amplified by PCR. The PCR product was purified and determined nucleotide sequence. Results The pathogen for the two outbreaks were influenza A （H3N2） virus. But farther analysis with nucleotide sequence showed that the antigenic of influenza A （H3N2） virus which cause these two epidemic situation had greater differences, there were 10 variation in nucleotide and 5 changes in amino acid, furthermore, there were 3 amino acid changes befallen in important sites which were antigenic determinant. Their homology is 98.5 %. It showed that the influenza A （H3N2） viruses that isolated in two outbreaks did not come from same viral strain; they were two different period viral strains in evolvement. Conclusion In same epidemic periods, the epidemic strains was not selfsame. The influenza virus after antigenic drift can be caused an epidemic outbreak, so long as there are more easily infected group, originally viruses will lead to an epidemic outbreak of influenza.
出处
《中国计划免疫》
2005年第5期368-370,共3页
Chinese Journal of Vaccines and Immunization
