2000—2007年佛山市甲1亚型（H1N1）流感病毒监测情况及其HA1基因的变异

目的分析2000—2007年佛山市甲1亚型（H1N1）毒株流行情况及其HA1基因变异情况。方法用MDCK细胞分离流感病毒，采用血球凝集抑制试验进行型别鉴定，选取每年2～4株甲1亚型毒株的细胞培养物提取病毒核酸，进行HA1基因的逆转录，对其核苷酸和氨基酸序列及亲缘关系进行分析。结果病毒分离结果显示2000—2007年间甲1亚型流感病毒在佛山市人群中的流行是间断性的，只在2000、2001、2005、2006年4个年份分离到甲1亚型流感毒株。毒株的HAl区氨基酸序列与流感疫苗推荐株A／NewCMedonia／20／99和A／Solomon Islands／3／2006相比，同源性分别为97．2％～99．7％和97．2％-98．5％。氨基酸残基平均替换数随年份的推移而增加，只有2006年的毒株在抗原决定簇发生了替换。结论与疫苗株比较，佛山市的甲1亚型流感毒株抗原性已逐渐发生了改变，应密切注意疫苗对毒株的免疫效果。

Study of the HIN1 influenza virus strains isolated in Foshan and the amino acid sequence divergence of the HA1 gene, 2000 - 2007

Objective To study the characteristics of influenza virus activity and the genetic and antigenic features of HA1 gene of influenza A（ H1N1 ） virus circulated in Foshan from 2000 to 2007. Methods According to the result of the hemagglutination inhibition （HI） test, viral RNA was extracted from cell culture fluid of the influenza A（ H1N1 ） virus strain. HA1 gene was obtained by RT -PCR and sequenced for analysis of the genetic and antigenic characteristics. Results Influenza A （ H1 N1 ） viruses were not continually cocirculating in human in Foshan. Compared with the recommended influenza vaccine strains of A/New Caledonia/20/99 and A/Solomon Islands/3/2006, the homologies of HA1 amino acid sequences of the H1N1 virus strains in Foshan were 97.2% - 99.7% and 97.2% - 98.5% , respectively. Mean amino acid substitution numbers were increasing as time went by. Conclusion Compared with vaccine strains, the antigenicity of influenza A（ H1 N1 ） virus strains isolated in Foshan City has been gradually changed. Therefore, close attention to the immune effect of influenza vaccine should be paid.