School of Life Sciences, East China Normal University, Shanghai 200062, China.
Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China.
Poult Sci. 2018 Nov 1;97(11):3793-3800. doi: 10.3382/ps/pey187.
Circulating H7N9 influenza viruses in live poultry markets continue to pose a threat to human health. Free-range poultry, one of the sources for these markets, are common in China as well as in many developing countries. Because the H9N2 virus could be a source of internal genes for the H7N9 virus, we conducted surveillance in free-range poultry and live poultry markets to study the evolution of H7N9 and H9N2 viruses in Eastern China. We found 28 samples positive for the H9N2 virus (a rate of 3.2%), but no positive samples for the H7N9 virus. Six representative H9N2 isolates were sequenced and analyzed, and the results showed that these viruses shared high nucleotide identities (99.0 to 100%) and were in a same branch in the phylogenetic trees. All these 6 viruses are closely clustered with Zhejiang H9N2 chicken isolates, and belonged to genotype G57, along with some novel H7N9 strains and H9N2 strains circulating in humans in China. We hope that surveillance of AIVs in free-range poultry will be strengthened for further identification more genetic diversity.
活禽市场中循环的 H7N9 流感病毒继续对人类健康构成威胁。散养家禽是这些市场的来源之一，在中国和许多发展中国家都很常见。由于 H9N2 病毒可能是 H7N9 病毒的内部基因来源，我们在中国东部的散养家禽和活禽市场进行了监测，以研究 H7N9 和 H9N2 病毒的演变。我们发现了 28 份 H9N2 病毒阳性样本（阳性率为 3.2%），但没有 H7N9 病毒阳性样本。我们对 6 个有代表性的 H9N2 分离株进行了测序和分析，结果表明这些病毒具有很高的核苷酸同一性（99.0%到 100%），并在系统进化树中处于同一分支。所有这 6 种病毒都与浙江 H9N2 鸡分离株密切聚类，属于基因型 G57，与中国流行的一些新型 H7N9 株和 H9N2 株有关。我们希望加强对散养家禽中 AIV 的监测，以进一步识别更多的遗传多样性。
