H6N6亚型禽流感病毒广东分离株分子遗传演化分析

Phylogenetic Analysis of H6N6 Subtype Avian Influenza Virus from Guangdong

2010年至2011年在中国广东地区活禽交易市场进行流行病学调查时,在鸭咽和泄殖腔拭子中分离到2株H6N6亚型禽流感病毒,分别命名为A/Duck/Guangdong/C45/2010(H6N6)、A/Duck/Guangdong/C120/2011(H6N6)。应用RT-PCR分别对2株毒株的8个基因片段进行了克隆、测序与分析,结果表明:2毒株的HA裂解位点附近的氨基酸序列为P-Q-I-E-T-R-G,只有1个碱性氨基酸,符合低致病性禽流感病毒HA裂解位点附近的氨基酸序列特征;与2毒株HA基因相似性最高的毒株为A/Duck/Guangxi/GXd-5/2010(H6N1),与NA基因相似性最高的毒株分别为A/Duck/Fujian/3242/2007(H6N6)和A/Duck/Fujian/6159/2007(H6N6)。全基因组分子遗传演化分析表明,2毒株的8个基因片段均属于欧亚谱系的禽源演化分支;但HA基因属于ST2853-like分支,NP基因属于HN573-like分支,PB2、PB1、PA、M和NS基因属于ST339-like分支,说明本研究中的2株病毒为不同基因群间基因交换的重组病毒。因此,有必要加强H6亚型禽流感病毒流行病学调查以便及时关注其遗传变异与致病性进化,为中国禽流感的预防与控制提供数据支持和理论指导。

Two H6N6 subtype avian influenza viruses(AIV),A/Duck/Guangdong/C45/2010(H6N6)and A/Duck/Guangdong/C120/2011(H6N6),were isolated from the live-poultry markets of Guangdong during 2010 to 2011.The sequence analysis of the hemagglutinin(HA)gene showed that the isolates were categorized as low pathogenic AIV,with the typical HA cleavage site of P-Q-I-E-T-R-G.The HAgene of the two isolates was closely related to that of A/Duck/Guangxi/GXd-5/2010(H6N1).The NAgenes of the two isolates were closely related to that of A/Duck/Fujian/3242/2007(H6N6)and A/Duck/Fujian/6159/2007(H6N6),respectively.The phylogenic analysis indicated that the eight genes of the two isolates belonged to the Eurasian avian lineage.The HAand NPgenes of them belonged to ST2853-like lineage and HN573-like lineage,respectively.However,the other genes of them belonged to ST339-like lineage.Those indicated that the two isolates were recombinant viruses resulted from different genotype viruses.Therefore,we should focus on studying the pathogenic evolution and genetic variation of H6N6 subtype AIV to prevent and control the AIV.