State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
Guangzhou 8th People's Hospital, Guangzhou Medical University, Guangzhou, 510060, China.
Sci China Life Sci. 2017 Dec;60(12):1331-1339. doi: 10.1007/s11427-017-9152-1. Epub 2017 Oct 9.
Pathogenic H7N9 influenza viruses continue to pose a public health concern. The H7N9 virus has caused five outbreak waves of human infections in China since 2013. In the present study, a novel H7N9 strain (A/Guangdong/8H324/2017) was isolated from a female patient with severe respiratory illness during the fifth wave of the 2017 H7N9 epidemic. Phylogenetic analysis showed that the H7N9 viruses collected during the fifth wave belong to two different lineages: the Pearl River Delta lineage and the Yangtze River Delta lineage. The novel isolate is closely related to the Pearl River Delta H7N9 viruses, which were isolated from patients in Guangdong Province. The novel H7N9 isolate has an insertion of three basic amino acids in the cleavage site of hemagglutinin (HA), which may enhance virulence in poultry. The 2017 isolate also possesses an R292K substitution in the neuraminidase (NA) protein, which confers oseltamivir resistance. This study highlights the pandemic potential of the novel H7N9 virus in mammals; thus, future characterization and surveillance is warranted.
高致病性 H7N9 流感病毒仍然是一个公共卫生关注点。自 2013 年以来，H7N9 病毒已在中国引发了五波人类感染疫情。在本研究中，从一名患有严重呼吸道疾病的女性患者中分离到了一株新型 H7N9 毒株（A/广东/8H324/2017）。系统进化分析显示，第五波疫情中采集的 H7N9 病毒属于两个不同的谱系：珠江三角洲谱系和长江三角洲谱系。新型分离株与从广东省患者中分离到的珠江三角洲 H7N9 病毒密切相关。新型 H7N9 分离株的血凝素（HA）裂解位点插入了三个碱性氨基酸，这可能增强了其在禽类中的毒力。2017 年分离株的神经氨酸酶（NA）蛋白也存在 R292K 取代，这使其对奥司他韦产生耐药性。本研究强调了新型 H7N9 病毒在哺乳动物中的大流行潜力；因此，有必要对其进行进一步的特征描述和监测。
