宁夏地区H1N1亚型猪流感病毒基因组遗传进化分析

Phylogenetic analysis of H1N1 swine influenza viruses isolated from Ningxia

对宁夏地区2011年分离到的5株H1N1亚型猪流感病毒进行了基因组测定和遗传进化分析。结果显示:宁夏地区H1N1亚型猪流感病毒具有多样性,5株分离株可分为3类,其中1株为类人H1N1猪流感病毒,2株为经典猪流感病毒,另外2株为重组猪流感病毒,其PB2、PB1、PA、NP、NS基因来源于北美三元重组猪流感病毒,HA、NA、M基因来源于经典猪流感病毒;HA蛋白裂解位点附近氨基酸分析显示5株H1N1亚型猪流感分离株均为低致病性毒株;序列分析结果显示5株病毒在HA蛋白受体结合位点、抗原位点,以及NA蛋白潜在糖基化位点处氨基酸存在差异,这些差异具有分支特异性。5株病毒在NA和M2蛋白上均未出现与神经氨酸酶抑制剂和金刚烷胺耐药性相关的氨基酸变异,但其中3株病毒的PB2蛋白基因具有哺乳动物适应性变异E627K。

In this study,5 H1N1 swine influenza viruses （SIV） isolated from Ningxia Hui Autono- mous Region in 2011 were completely sequenced and phylogeneticly analyzed. The results showed that genetic diversity was found in these isolates,one strain belonged to human-like H1N1 SIV lineage,two strains were located into classical H1N1 SIV lineage,and another two viruses were reassortant viruses with PB2,PB1 ,PA, NP and NS genes originating from North American triple site. Among 5 viruses, amino acid differences were identified in receptor-binding sites, antigenic classified as low pathogenic influenza viruses according to analysis of amino acids at HA cleavage sites in HA protein,and glycosylation sites in NA protein,which were lineage specificity. Amino acid substitutions associated with resistance to neuraminidase inhibitor and amantadine were not found in NA and M2 proteins,but PB2 E627K associated with mammalian adaptation were identi- fied in 3 viruses.