畜牧兽医学报 ›› 2018, Vol. 49 ›› Issue (10): 2205-2214.doi: 10.11843/j.issn.0366-6964.2018.10.016

• 预防兽医 • 上一篇    下一篇

6株H9N2亚型禽流感病毒的分子演化和抗原变异分析

黄艳艳1, 李悦1,2, 张琳1, 王进圣3, 吴福杰3, 吴家强1*, 刘思当2*   

  1. 1. 山东省农业科学院畜牧兽医研究所, 山东省畜禽疫病防治与繁育重点实验室, 济南 250100;
    2. 山东农业大学动物科技学院, 泰安 271018;
    3. 山东凤祥股份有限公司, 阳谷 252300
  • 收稿日期:2017-11-23 出版日期:2018-10-23 发布日期:2018-10-23
  • 通讯作者: 吴家强,E-mail:wujiaqiang2000@sina.com;刘思当,E-mail:liusidang@126.com
  • 作者简介:黄艳艳(1977-),女,山东泰安人,副研究员,博士,主要从事动物病毒学与免疫学研究,E-mail:506785625@qq.com;李悦(1995-),女,山东济南人,硕士生,主要从事动物病理学研究,E-mail:18706385355@163.com
  • 基金资助:

    十二五国家科技支撑计划(2015BAD12B03);泰山学者特聘专家工程经费(ts201511069);山东省农业科学院科技创新工程(CXGC2016B14);禽流感监测诊断及综合防控

Molecular and Antigenic Analyses of Six H9N2-subtype Avian Influenza Viruses Isolated from Broiler Chicken Farms of Shandong Province in 2017

HUANG Yan-yan1, LI Yue1,2, ZHANG Lin1, WANG Jin-sheng3, WU Fu-jie3, WU Jia-qiang1*, LIU Si-dang2*   

  1. 1. Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan 250100, China;
    2. College of Animal Science, Shandong Agricultural University, Tai'an 271018, China;
    3. Shandong Feng Xiang Co. LTD, Yanggu 252300, China
  • Received:2017-11-23 Online:2018-10-23 Published:2018-10-23

摘要:

H9N2亚型禽流感持续在我国鸡群中广泛流行,为了明确2017年山东省聊城市一肉鸡场H9N2亚型禽流感病毒的分子演化和抗原变异情况,对6株H9N2亚型病毒分离株进行了基因扩增、序列测定和进化分析,并分别使用病毒分离株和疫苗株抗原进行血凝抑制试验,比较免疫鸡血清的抗体效价差异。结果如下:NCBI Blastn分析表明,与各分离株基因同源性最高的序列分别来源于山东、河北、上海、江苏、浙江、江西、湖南、广东和日本等地的分离株,表明H9N2亚型禽流感病毒传播范围广,基因重排活跃。各基因的系统进化分析表明,分离株的8个基因片段分别与禽流感病毒欧亚分支的A/duck/HongKong/Y280亚系、A/quail/HongKong/G1/97亚系以及A/chicken/Shanghai/F/98亚系进化关系密切。从病毒基因型上来分析,6株病毒均隶属于2010年以来在国内鸡群中广泛流行的G57基因型。与耐药性相关的氨基酸位点分析表明,病毒M2蛋白存在S31N变异,表明病毒对离子通道蛋白抑制剂耐药。对1 000份疫苗免疫鸡血清进行血凝抑制抗体效价的检测,发现H9N2亚型禽流感分离株抗原与疫苗用标准抗原相比,所测得的血凝抑制抗体滴度平均低1~2 log2,表明二者HA抗原性略有差异。总之,2017年在该肉鸡场流行的这6株H9N2亚型禽流感病毒仍然为G57基因型,分离株的HA抗原反应性与疫苗株略有差异。

Abstract:

Avian influenza of H9N2 subtype has been prevalent in chicken flocks of China for years. To elucidate the molecular evolution and antigenic mutation of H9N2 viruses in a chicken farm of Liaocheng, Shandong province in 2017, 6 viruses isolated were analyzed for their molecular characteristics through whole-genome sequencing, and compared with the vaccine strain for their reactivity by Hemagglutination inhibitation test. Nucleotide blast results showed that gene sequences most homologous to each gene segment of the isolates were detected from many reference viruses of wide geographic range including Shandong, Hebei, Shanghai, Jiangsu, Zhejiang, Jiangxi, Hunan, Guangdong and Japan. These results indicated the extensive transmission of the viruses and the frequent reassortment of the viral genes. Phylogenetic analysis revealed that the 8 gene segments of the viruses were closely related to several phylogenetic clades of Eurasian avian lineage, including A/duck/HongKong/Y280-clade, A/quail/HongKong/G1/97-clade and A/chicken/Shanghai/F/98-clade. Genotypic analysis showed that all 6 viral isolates belonged to G57 genotype, which has been the dominant H9N2 genotype in China since 2010. Analysis of key amino acids related to drug resistance demonstrated mutation of S31N of M2 protein, a molecular marker related to viral resistance to ion channel protein inhibitors. In addition, 1 000 serum samples were tested for their antibody level against H9N2 AIVs in cross hemagglutination inhibitation test, with antigens of viral isolates and the vaccine strain, respectively. Antigens of viral isolates resulted in 1 to 2 log2 lower antibodies in comparison with the vaccine antigen, indicating minor HA antigenic difference between the prevalent viral strain and the vaccine strain. In conclusion, we found that the 6 H9N2 avian influenza viruses prevalent in the chicken flock in 2017 belonged to G57 genotype, and there is a slight difference in HA reactivity between the isolates and the vaccine strain.

中图分类号: