Environmental connections of novel avian-origin H7N9 influenza virus infection and virus adaptation to the human
Environmental connections of novel avian-origin H7N9 influenza virus infection and virus adaptation to the human
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DOI：
10.1007/s11427-013-4491-3
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发表时间：
2013-06-01
影响因子：
9.1
通讯作者：
Pan JingCao
中科院分区：
文献类型：
--
作者：
Li Jun;Yu XinFen;Pan JingCao
一种新型H7N9甲型流感病毒被发现是中国上海新出现的急性呼吸道感染病例的病原体。这种病毒也已确定在感染病例在邻近地区杭州市在浙江省。在这项研究中，收集并分析了杭州3例确诊感染新型H7N9甲型流感病毒的患者的流行病学、临床和病毒学数据。通过实时逆转录PCR（RT-PCR）和测序对来自接触过的自由市场的人呼吸道标本和鸡粪便进行流感病毒检测。3例患者的临床特征相似，均为高热和严重的呼吸道症状，但仅1例死亡。与其他已报道的H7N9甲型流感病毒相比，从人类样本中测序的三种杭州病毒之间观察到一定程度的多样性。杭州市禽源H7N9流感病毒序列中存在与人类适应相关的重要氨基酸替换。其中一株杭州病毒在血凝素受体结合区发生了一个新的氨基酸替换（Q226 I）。更重要的是，从鸡粪便中测序的病毒在PB 2蛋白中具有627 E取代，而不是在来自三名患者的杭州病毒的PB 2蛋白中发现的经西氏适应的627 K取代。因此，新出现的H7N9病毒可能处于适应压力之下，这将有助于它从禽类宿主“跳”到人类宿主。这些替代的意义需要进一步探索，实验室实验和广泛的实地监测。
A novel H7N9 influenza A virus has been discovered as the causative identity of the emerging acute respiratory infection cases in Shanghai, China. This virus has also been identified in cases of infection in the neighboring area Hangzhou City in Zhejiang Province. In this study, epidemiologic, clinical, and virological data from three patients in Hangzhou who were confirmed to be infected by the novel H7N9 influenza A virus were collected and analyzed. Human respiratory specimens and chicken feces from a contacted free market were tested for influenza virus by real-time reverse transcription PCR (RT-PCR) and sequencing. The clinical features of the three cases were similar featured with high fever and severe respiratory symptoms; however, only one of the patients died. A certain degree of diversity was observed among the three Hangzhou viruses sequenced from human samples compared with other reported H7N9 influenza A viruses. The sequences of the novel avian-origin H7N9 influenza viruses from Hangzhou City contained important amino acid substitutions related to human adaptation. One of the Hangzhou viruses had gained a novel amino acid substitution (Q226I) in the receptor binding region of hemagglutinin. More importantly, the virus sequenced from the chicken feces had a 627E substitution in the PB2 protein instead of the mammalian-adapted 627K substitution that was found in the PB2 proteins from the Hangzhou viruses from the three patients. Therefore, the newly-emerging H7N9 virus might be under adaptation pressure that will help it "jump" from avian to human hosts. The significance of these substitutions needs further exploration, with both laboratory experiments and extensive field surveillance.