摘要
目的 通过浙江省1998-2005年甲3亚型流行性感冒（流感）病毒的神经氨酸酶（NA）基因的序列比较，阐明近几年NA基因的变异与流感流行的关系。方法 对浙江省1998～2005年流感流行期间分离的甲3亚型流感代表性毒株，采用逆转录-聚合酶链反应（RT—PCR）扩增病毒NA基因，进行核苷酸序列测定，并用Bio-Edit软件作分析处理。结果 浙江省近几年流感流行期间分离到甲3亚型流感病毒代表株13株，其NA基因核苷酸长度均为1338bp，由此推导的氨基酸数为446个。1998-2005年甲3亚型流感病毒在NA基因区发生可遗传的氨基酸变异达22个，其中1998-1999年、1999～2002年变异最大，均达到9个氨基酸的差异；2003年后病毒的变异趋向平稳，这与NA基因系统进化树的结果相一致。此外，近几年来世界卫生组织推荐的甲3亚型流感疫苗株与当年的流感流行株之间存在一定的差异，而在2003年后的甲3亚型流感疫苗株与当年的流感流行株之间的符合程度较好。结论 近年来浙江省甲，亚型流感病毒的NA区域与血凝素区域相似，均发生了较大的抗原性漂移，提示1999～2005年发生的2次流感流行是由于当年的甲3亚型流感分离株变异影响到病毒的抗原性所导致的。
Objective To illustrate the relation between the variation of NA gene and the prevalence of Influenza through sequence alignment of NA gene among the Influenza A3 strains circulating in Zhejiang Province in recent years. Method NA gene of the representative strains of Influenza A3 isolated in outbreaks during 1998 - 2005 in Zhejang Province were amplified by reverse transcription polymerase chain reaction （RT-PCR）. PCR products were purified and sequenced, then data were analyzed with biologic software bioEdit. Results Thirteen representative strains of Influenza A3 were isolated from the outbreak in recent years, which NA gene were all 1338bp, amino acid were all 446. During 1998 - 2005,22 amino acid variated in NA gene of Influenza A3. Especially during 1998 - 1999 and 1999 - 2002,9 amino acid have variated in NA gene. After 2002, according with the analytic results of phylogenic trees of NA gene, the variation of Influenza A3 become balanced. In addition, there are some differences between the vaccine strains recommended by WHO and circulating strains. However, vaccine strains recommended by WHO accorded with the circulating strains primely after 2003. Conclusion In recent years, antigenic drift of NA gene may occur on Influenza A3 circulating in Zhejiang Province, suggesting the cause of the two Influenza outbreaks during 1999 -2005 may due to the antigentic change effected by the variation of the Influenza isolates.
出处
《中国计划免疫》
2006年第5期406-410,共5页
Chinese Journal of Vaccines and Immunization
