Shanghai Animal Disease Control Center, People's Republic of China.
Arch Virol. 2012 Jun;157(6):1193-8. doi: 10.1007/s00705-012-1266-2. Epub 2012 Mar 10.
The H9N2 influenza virus is endemic in poultry. We report its occurrence in live-poultry markets, fair-trade markets and poultry farms in the Shanghai region between September 2006 and December 2010. An analysis of partial sequences of the HA, NA, PB1, PB2 and NP genes of eleven distinct H9N2 isolates revealed that all carried an RSSR motif at the cleavage site of HA, diagnostic of low pathogenicity in chickens. A phylogenetic analysis indicated that these isolates are derived from the lineage represented by Duck/HK/Y280/97, but they have evolved a range of reassortments. Their PB1 and NP sequences resembled those of H5N1 strains, indicating a hybrid origin involving both H9 and H5 strains. The HA and NA sequences present in all eleven isolates resembled those of the Duck/HK/Y280/97-like lineage. Infection by H9N2 is commonplace in Shanghai live-poultry markets, allowing the viruses to have evolved rapidly.
H9N2 流感病毒在禽类中流行。我们报告了 2006 年 9 月至 2010 年 12 月期间，在上海地区的活禽市场、公平贸易市场和家禽养殖场中发生的情况。对 11 个不同的 H9N2 分离株的 HA、NA、PB1、PB2 和 NP 基因的部分序列进行分析表明，所有分离株的 HA 裂解位点都带有 RSSR 基序，表明对鸡具有低致病性。系统进化分析表明，这些分离株源自 Duck/HK/Y280/97 代表的谱系，但已进化出一系列重配。它们的 PB1 和 NP 序列与 H5N1 株相似，表明涉及 H9 和 H5 株的混合起源。所有 11 个分离株中的 HA 和 NA 序列与 Duck/HK/Y280/97 样谱系相似。H9N2 在上海活禽市场的感染很常见，使病毒得以迅速进化。
