1999-2008年广东省韶关市H3亚型流行性感冒病毒的变迁

The vicissitudes of influenza virus subtype H3 from 1999 to 2008 in Shaoguan city

目的通过A型流行性感冒(流感)病毒H3亚型血凝素HA1基因的变异,探讨韶关市1999-2008年H3亚型流感病毒的变迁。方法复苏韶关市疾病预防控制中心保存的历年H3亚型流感毒株,提取病毒RNA,RT-PCR扩增病毒HA1基因,纯化产物进行核苷酸序列测定,使用DNAStart MegAlign等生物软件包对序列进行分析。结果研究测定了4个年份的流感毒株,与代表株A/Panama/2007/1999相比,同源性为91.3%～93.8%,在5个抗原决定簇共14个氨基酸发生变异,RBS上有6个位点发生变异,各毒株均在不同的位点上增加了一个糖基化位点;与代表株A/Fujian/411/2002比较,同源性为90.2%～97.7%,18个氨基酸变异发生在5个抗原决定簇,10个氨基酸变异发生在RBS,A/SG/199/1999,A/SG/y009/2008分别增加了一个糖基化位点;与代表株A/Wisconsin/67/2005比较,同源性从88.3%～98.4%,共有14个氨基酸变异发生在5个抗原决定簇,RBS上有9个氨基酸发生变异,各毒株均在不同的位点上增加了一个糖基化位点;本次研究的毒株变异率逐渐下降,变异最活跃的两个氨基酸第158和173位点分别位于B和D抗原决定簇。结论韶关市H3亚型流感病毒在1999-2008年间发生了3次抗原性变异,每一次变异大约间隔3～4年。从2008年的氨基酸变异情况得知,H3亚型流感病毒的抗原性漂移有增强的趋势。

Objective To investigate the vicissitudes of influenza virus subtype H3 in Shaoguan by the viriation of hemagglutinin HA1 domain of influenza A virus. Methods Recovered the influenza virus strains by MDCK cell, Virion RNA were extracted and amplified by RT-PCR, The PCR were purified and test gene sequence, Edit the sequences by Bio-edit, DNA Start. Then compare and analyse the sequences using Clustal-W、 Bio-edit, Treeview software. Results Four strains had tested, sequence analysis showed that the HA1 domain of these strains had 91.3% -93.8% homology with the vaccine strain A/Panama/2007/1999, 14 amino acids variation was observed in 5 antigenic deteminants, 6 amino acids variation in RBS, and one more glycosylation site at different site in each strain; Compared with the vaccine strain A/Fujian/411/2002, the homology was 90.2% -97.7 %, 18 amino acids variation was observed in 5 antigenic deteminants, 10 amino acids variation was observed in RBS, and there was one more glycosylation site in strains A/SG/199/1999 and A/SG/y009/2008; Compared with the vaccine strain A/Wisconsin/ 67/2005, the homology was 88.3% -98.4%, 14 amino acids variation was observed in 5 antigenic deteminants, 9 amino acids variation was observed in RBS, one more glycosylation site at different site in each strain; The mutation rate decrease gradually in these strains, the most two active amino acid site was in B and D antigenic determinant respectively. Conclusion There were three times antigen drift of influenza virus subtype （H3） were occurred in Shaoguan between 1999-2008, they were in 1999, 2002 or 2003, 2007 respectively; every variation had 3 -4 years intervals. The trend of the antigen drift of influenza virus subtype（H3） strengthen from the situation of 2008.