流感病毒泰山分离株H1N1亚型血凝素HA1基因特征分析

Research on genetic characteristics in the HA1 of influenza A(H1N1) viruses isolated in Taian City

目的分析泰安市2005-2008年流感病毒H1N1亚型的基因特征及抗原变异情况,为流感防治提供技术支持。方法采集流感样病例的鼻咽拭子标本,用MDCK细胞进行流感病毒的病原分离,采用红细胞凝集试验测定病毒的滴度,用血凝抑制实验和RT-PCR进行流感病毒型别鉴定,通过RT-PCR扩增血凝素HA1片段的基因,电泳、纯化后进行基因序列测定,利用生物信息学进行序列分析。结果2005-2008年共检测咽拭子样本615份,分离出流感病毒121株,其中H1N1亚型4株。对分离的甲型H1N1毒株HA1基因进行分析,有3株病毒序列在多个氨基酸位点上发生变异,其中2007、2008年分离株和2005年分离株相比,各发生了5个和8个突变;2005、2007和2008年分离株分别与当年度的疫苗株相比,各发生了8个、11个和8个突变。和国际标准株、本年度的疫苗株A/Brisbane/59/2007(H1N1)比较,3株流感病毒共计有22个位点发生了变异。结论在近几个年度的流行季节中,该地区有H1N1亚型流感的存在。该地H1N1流感病毒分离株有多处氨基酸发生替换,氨基酸的替换导致毒株的抗原性发生了漂移。

Objective To analyze the data of influenza A （H1N1） viruses surveillance and genetic characteristics from Taian City during 2005 - 2008, so a scientific basis can be provided for the preven- tion and treatment of influenza. Methods The specimens from Influenza-Like Illness（ILI） were collected. The viruses were isolated with MDCK cell and identified with HAl and RT-PCR. The product of PCR were sequenced. Then the sequences were analyzed through biometrie software. Results A total of 121 influenza strains were obtained from 615 specimens, and 4 of them were identified as A（H1N1 ） subtype. There were 3 strains mutated on several sites. Compared with strains isolated in 2005, there were 5 and 8 mutations in the amino acid sequences of virus strains isolated in 2007 and 2008 respectively. And there were a total of 22 amino acid mutations compared with A/Brisbane/59/2007 （H1N1）. Conclusions Influenza type A（H1N1） are detected in Taian City. There are several mutations in the amino acid sequences of virus strains isolated in Taian. The antigenic drift of virus strains is due to accumulation of amino acid substitutions