Zhang Zhijie, Li Rui, Jiang Lufang, Xiong Chenglong, Chen Yue, Zhao Genming, Jiang Qingwu
Department of Epidemiology and Biostatistics, School of Public Health, Fudan University, Shanghai, People's Republic of China.
Key Laboratory of Public Health Safety, Ministry of Education, Fudan University, Shanghai, People's Republic of China.
BMC Infect Dis. 2016 Oct 25;16(1):600. doi: 10.1186/s12879-016-1932-1.
Novel avian influenza viruses (AIVs) of H7N9, H10N8, and H5N6 are currently circulating in China's poultry flocks, occasionally infecting human and other mammals. Human infected AIV H5N6 in China during 2014-2015 is believed to be a triple reassortant originated from H6N6 and two clades of H5 viruses. The current report suggests that its reassortment history is more complicated.
Genomes of human infected isolates of AIV H5N6 were searched from the NCBI Influenza Virus Sequence Database and the Global Initiative on Sharing Avian Influenza Data. Sequences shared high identities with each segment of their genomes were obtained through the Basic Local Alignment Search Tool. Alignments were done by mafft-7.037-win32 program; 8 large-scale and then 8 gradually converged phylogenetic trees were constructed by using MEGA5.1/5.2/6.0 Software.
The events that each segment of the genomes of human infected AIV H5N6 isolates circulated in China had evolved into its current status might have happened before 2013, and so were they then reassorted into the epidemic AIV H5N6. A/Guangzhou/39715/2014(H5N6) and A/Sichuan/26221/2014(H5N6) had their six internal segments (PB2, PB1, PA, NP, NEP, and M) in common, and were reassorted from AIVs H5N1 in the same period and same region as that of HA, while A/Yunnan/0127/2015(H5N6) derived its six internal segments from AIV H9N2 that has been prevalent in Eastern China since 2008.
AIV H5N6 isolates established from both human and poultry in China during 2014-2015 were heterogeneous; both AIVs H5N1 and H9N2 were involved in the reassortment of AIV H5N6 in China.
新型H7N9、H10N8和H5N6禽流感病毒目前在中国家禽群体中传播，偶尔会感染人类和其他哺乳动物。2014 - 2015年期间在中国感染人类的H5N6禽流感病毒被认为是一种三重重配病毒，起源于H6N6和两个H5病毒分支。目前的报告表明其重配历史更为复杂。
从NCBI流感病毒序列数据库和全球共享禽流感数据倡议组织中搜索人类感染的H5N6禽流感病毒分离株的基因组。通过基本局部比对搜索工具获得与其基因组各片段具有高度同源性的序列。使用mafft - 7.037 - win32程序进行比对；使用MEGA5.1/5.2/6.0软件构建8个大规模然后8个逐渐收敛的系统发育树。
在中国流行的人类感染的H5N6禽流感病毒分离株基因组各片段演变成其当前状态的事件可能发生在2013年之前，随后它们重配形成了流行的H5N6禽流感病毒。A/广州/39715/2014（H5N6）和A/四川/26221/2014（H5N6）有六个内部片段（PB2、PB1、PA、NP、NEP和M）相同，并且是在与HA相同的时期和地区从H5N1禽流感病毒重配而来，而A/云南/0127/2015（H5N6）的六个内部片段来自自2008年以来在中国东部流行的H9N2禽流感病毒。
2014 - 2015年期间在中国从人类和家禽中分离出的H5N6禽流感病毒分离株是异质的；H5N1和H9N2禽流感病毒都参与了中国H5N6禽流感病毒的重配。
