Genetic analysis of H9N2 avian influenza viruses isolated from India
Genetic analysis of H9N2 avian influenza viruses isolated from India
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DOI：
10.1007/s00705-008-0131-9
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发表时间：
2008-08-01
影响因子：
2.7
通讯作者：
Dubey, S. C.
中科院分区：
文献类型：
--
作者：
Tosh, C.;Nagarajan, S.;Dubey, S. C.
H9N2禽流感病毒在亚洲家禽中流行，分为三个主要亚系，分别为A/鸭/香港/Y280/97 （y280样）、A/鹌鹑/香港/G1/97 （g1样）和A/鸡/韩国/38349-p96323/96（韩国样）。为了了解印度病毒的遗传关系，我们测定了2003-2004年间从印度鸡中分离的5种H9N2禽流感病毒的部分核苷酸序列，并将它们与GenBank中现有的H9N2序列进行了比较。推导出的氨基酸序列分析显示，4个分离株在HA的裂解位点共享一个R-S-S-R/G基序，对鸡的致病性较低，而1个病毒在同一位置具有R-S-N-R/G基序。所有的病毒在HA受体结合位点都维持了类似人的226赖氨酸基序（H3编号）。系统发育分析表明，50%的基因（HA、NA、NP和M）与g1样病毒相似，而印度分离株的其余基因在欧亚谱系中形成了一个单独的、尚未定义的亚谱系。我们的发现为在印度流行的g1样病毒的新型重组H9N2基因型提供了证据。
H9N2 avian influenza viruses are endemic in domestic poultry in Asia and are grouped into three major sublineages represented by their prototype strains A/Duck/Hong Kong/Y280/97 (Y280-like), A/Quail/Hong Kong/G1/97 (G1-like) and A/Chicken/Korea/38349-p96323/96 (Korean-like). To understand the genetic relationship of Indian viruses, we determined the partial nucleotide sequence of five H9N2 avian influenza viruses isolated from chicken in India during 2003-2004 and compared them with H9N2 sequences available in GenBank. Deduced amino acid sequence analysis revealed that four isolates shared an R-S-S-R/G motif at the cleavage site of HA, representing low pathogenicity in chickens, while one virus harbors an R-S-N-R/G motif at the same position. All the viruses maintained the human-like motif 226Lysine (H3 numbering) at the HA receptor binding site. Phylogenetic analysis showed that 50% of the genes (HA, NA, NP and M) were similar to G1-like viruses, whereas the remaining genes of the Indian isolates formed a separate, not yet defined, sublineage in the Eurasian lineage. Our finding provides evidence of a novel reassortant H9N2 genotype of G1-like viruses circulating in India.