Avian Influenza A (H7N9) Virus in a Wild Land Bird in Central China, Late 2015.
Avian Influenza A (H7N9) Virus in a Wild Land Bird in Central China, Late 2015.
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2015 年末，中国中部野生陆禽体内感染甲型禽流感 (H7N9) 病毒。
DOI：
10.1007/s12250-018-0001-x
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Chen Jie
中科院分区：
文献类型：
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作者：
Yao Yanfeng;Zhang Tao;Yang Wenhai;Shao Zhiyong;He Bin;Chen Xiabing;Wu Lijun;Jin Erguang;Liu Haizhou;Chen Jianjun;Chen Jie
2013年初，中国长江三角洲地区报告了首例人感染甲型H7N9禽流感病毒病例（Liu et al. 2013）。自2013年初以来，世界卫生组织共报告了1533例经实验室确认的人感染禽流感H7N9病毒的病例（http：//www.hnnn.org）。who. int/csr/don/28-june-2017-ah 7 n9-china/en/），该病毒在中国发生了五次流行波。人感染高致病性H7N9流感病毒的情况在中国尤其多见（Zhang et al. 2017）。人类感染H7N9流感病毒的人数不断增加，令人担忧这些病毒将继续成为对公共卫生的潜在大流行威胁。研究表明，导致2013年中国疫情的H7N9病毒源自H7、N9和H9 N2禽流感病毒（AIV）之间的基因重配，H7N9病毒的内部基因似乎与野生陆地鸟类病毒（A/brambling/Beijing/16/2012，H9 N2）最密切相关（Chen et al. 2013; Liu et al. 2015）。因此，野生陆地鸟类可能在产生2013年H7N9病毒方面发挥了作用。在H7N9病毒持续流行期间，已从其他野生陆地鸟类物种中分离出H7N9病毒，包括树麻雀和野鸽（Zhao et al. 2014）。这些发现为野生陆地鸟类可能在H7N9亚型病毒传播中发挥重要作用提供了证据。在这里，我们报告了2015年底在中国中部首次从喜鹊中分离出H7N9病毒。采样地点位于武汉市郊区，毗邻那些村庄周围的一个小水池。在这些地区，鸟类自由放养，鸡和家禽（包括鸭和鹅）的混合是常见的。野鸟和家鸭共用同一片水域。在2015年10月至12月期间，收集了230份粪便样本，其中74份来自树麻雀（Passer montanus），49份来自喜鹊-知更鸟（Copsychus saularis），82份来自鸽子（Columba），25份来自斑鸠（Streptopelia turtur）。如前所述，通过线粒体分析鉴定样品的宿主（Cheung等人，2009年）。将新鲜粪便样品溶解在含有0.1%牛血清盐水（BSA）、2 9 106 U/L青霉素G、2 9 106 U/L阿替霉素B、250 mg/L吉他霉素、0.5 9 106 U/L制霉菌素、60 mg/L盐酸氧氟沙星和400 mg/L硫酸链霉素的PBS中进行病毒分离。将样品离心，并将获得的溶液接种到10日龄SPF含胚鸡蛋中。37 ℃孵育72 h后，收集尿囊液，测定其血凝活性.用M基因特异性逆转录聚合酶链反应（RT-PCR）证实HA阳性尿囊液。M基因阳性标本进一步进行亚型特异性RT-PCR分析。仅一份粪便样本为流感病毒阳性，仅检测到H7和N9亚型特异性RNA。为了探讨该毒株与其他禽流感病毒的亲缘关系，对H7N9禽流感病毒A/Magpie-Robin/Hubei/
In early 2013, the first case of a human infection with avian influenza A (H7N9) virus was reported in the Yangtze River Delta region of China (Liu et al. 2013). Since early 2013, a total of 1533 laboratory-confirmed human infections with avian H7N9 viruses have been reported to the World Health Organization (http://www. who. int/csr/don/28-june-2017-ah7n9-china/en/), with five epidemic waves of this virus occurring in China. Human infections with the highly pathogenic H7N9 influenza virus have emerged particularly in China (Zhang et al. 2017). The increasing numbers of human infections with H7N9 influenza viruses raises concerns that these viruses will continue to be a potential pandemic threat to public health. It has been shown that the H7N9 virus responsible for the 2013 Chinese outbreak originated from gene reassortment among H7, N9 and H9N2 avian influenza viruses (AIVs), and it appears that the internal genes of the H7N9 viruses are most closely related to a wild land bird virus (A/brambling/Beijing/16/2012, H9N2)(Chen et al. 2013; Liu et al. 2015). Therefore, wild land birds may have played a role in generating the 2013 H7N9 viruses. During the ongoing epidemics with H7N9 viruses, H7N9 viruses have been isolated from other species of wild land birds, including tree sparrow and wild pigeons (Zhao et al. 2014). These findings provide evidence that wild land birds may play an important role in the transmission of H7N9 subtype viruses. Here, we report the first isolation of H7N9 virus from magpie-robin in central China, in late 2015. The location of the sampling site was in the suburb of Wuhan City adjacent to a small pool surrounding the villages. In these areas, birds are free ranging and mixing between chickens and domestic aquatic fowl (including ducks and geese) is common. The wild birds share the same area of water with domestic ducks. During October to December 2015, 230 fecal samples comprising 74 from tree sparrows (Passer montanus), 49 from magpie-robins (Copsychus saularis), 82 from pigeons (Columba), and 25 from Turtle Doves (Streptopelia turtur) were collected. The hosts for the samples were identified by mitochondrial analysis, as described previously (Cheung et al. 2009). For virus isolation, the fresh fecal samples were dissolved in PBS containing 0.1% bovine serum saline (BSA), 2 9 106 U/L penicillin G, 2 9 106 U/L amphotericin B, 250 mg/L kitasamycin, 0.5 9 106 U/L nystatin, 60 mg/L ofloxacin HCl and 400 mg/L streptomycin sulfate. The samples were centrifuged and the solution obtained was inoculated into 10-day-old SPF embryonated chicken eggs. After incubationat 37 C for 72 h, the allantoic fluid was collected and its haemagglutination (HA) activity was tested. The HA positive allantoic fluids were confirmed by M gene specific reverse transcriptase-polymerase chain reaction (RT-PCR). The M gene positive samples were further analyzed by subtype specific RT-PCR. Only one fecal sample was positive for influenza virus and only H7 and N9 subtype-specific RNAs were detected. To explore the genetic relationship between the strain we identified and other AIVs, the whole genome of the H7N9 virus, which named A/Magpie-Robin/Hubei/