Guo YuanJi, Xie Jianping, Wu Kunyu, Dong Jie, Wang Min, Zhang Ye, Guo Junfeng, Chen Jiming, Chen Zhifing, Li Zi
Institute of Virology, Chinese Academy of Preventive Medicine, Beijing 100052, China.
Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi. 2002 Jun;16(2):142-5.
To understand the characterization of genome of a strain of avian influenza A H9N2 virus repeatedly isolated from a child with influenza illness. Thereafter to reveal the origin of this H9N2 virus.
Viruses were passed in embryonated hen eggs and virion RNA was extracted from allantoic fluid and reverse transcribed to synthesize cDNA. cDNA was amplified by PCR and the PCR product was purified with a purification kit. Afterwards RNA sequence analysis was performed by dideoxynucleotide chain termination and a cloning method. Finally, phylogenetic analysis of the sequencing data was performed with MegAlign (Version 1.03) and Editseg (Version 3.69) softwares.
Genome of A/Guangzhou/333/99 (H9N2) virus was closely related to avian influenza A H9N2 virus, but obvious difference from that of A/Duck/Hong Kong/Y439/97(H9N2) virus, as well as its genome did not include any RNA segment derived from human influenza A virus. However, the genes encoding the HA,NA,NP and NS proteins of A/Guangzhou/333/99 virus were derived from those of G9 lineage virus, the rest genes encoding the M and three polymerase (PB2,PB1 and PA) proteins were derived from G1 lineage strain.
A/Guangzhou/333/99 virus was a reassortant derived from reassortment betweenG9 and G1 lineages of avian influenzaA(H9N2) viruses. Therefore, the most possibility is that it is derived from avian influenza A virus directly. The results do not only demonstrate that avian influenza A (H9N2) virus could infect men, but also firstly prove that the genetic reassortment could be occurred between different genetic lineages of avian influenza A (H9N2) viruses in the nature.
了解从一名流感患儿反复分离出的一株甲型H9N2禽流感病毒的基因组特征，进而揭示该H9N2病毒的起源。
病毒在鸡胚中传代，从尿囊液中提取病毒粒子RNA并逆转录合成cDNA。通过PCR扩增cDNA，并用纯化试剂盒纯化PCR产物。之后采用双脱氧核苷酸链终止法和克隆方法进行RNA序列分析。最后，使用MegAlign（版本1.03）和Editseg（版本3.69）软件对测序数据进行系统发育分析。
A/广州/333/99（H9N2）病毒的基因组与甲型H9N2禽流感病毒密切相关，但与A/鸭/香港/Y439/97（H9N2）病毒的基因组有明显差异，且其基因组不包含任何源自甲型人流感病毒的RNA片段。然而，A/广州/333/99病毒编码HA、NA、NP和NS蛋白的基因源自G9谱系病毒，其余编码M和三种聚合酶（PB2,PB1和PA）蛋白的基因源自G1谱系毒株。
A/广州/333/99病毒是甲型H9N2禽流感病毒G9和G1谱系之间重配产生的重配体。因此，其最有可能直接源自甲型禽流感病毒。这些结果不仅证明了甲型H9N2禽流感病毒可感染人类，还首次证明了自然界中甲型H9N2禽流感病毒的不同基因谱系之间可发生基因重配。
