青海湖周边家禽相关环境标本中H5N1亚型禽流感病毒特征分析

Characteristics of highly pathogenic avian influenza environments of surrounding areas of Qinghai Lake Huang

目的了解我国青海湖周边家禽中分离到的高致病性H5N1亚型禽流感病毒的抗原性和基因特性。方法将青海湖周边野鸟和家禽的环境标本采集处理后。接种SPF鸡胚分离病毒．将红细胞凝集阳性的标本通过real-time RT-PCR进行型别鉴定和亚型分析。将H5N1检测阳性的标本选取部分进行二代序列分析和抗原性分析。结果2013年1-9月问采集的家禽相关环境标本中共分离到19株高致病性H5N1亚型禽流感病毒，集中在1-3月。对7株病毒进行了全基因组序列分析和抗原性分析显示，血凝素基因进化树显示其中除A／Environment／Qinghai／XN02032／2013属于clade7．2分支病毒以外，其余6株属于clade2．3．2．1C分支。神经氨酸酶基因也显示该毒株与其他6株分属于两个不同的分支；抗原分析显示该毒株与所有参考血清低反应，另外6株病毒是A／Barnswallow／HongKong／D10—1161／2010的类似株。结论青海湖周边地区在2013年1-3月环境相关标本中检测到高致病性H5N1亚型禽流感病毒，属于clade2．3．2．1和clade7．2分支病毒。这种高致病性H5N1亚型禽流感病毒多个分支共同流行的趋势提示加强这一地区野鸟和家禽相关环境病原体监测的重要性。

Objective To understand the antigenic and genetic characteristics of highly pathogenic avian influenza I-ISN1 viruses isolated from poultry related environments of surrounding areas of Qinghai Lake. Methods Poultry and wild birds related environments from surrounding areas of Qinghai lake were collected and handled. Viruses were isolated with embryonated chicken eggs. The virus subtyping was performed by real-time RT-PCR. The highly pathogenic avian influenza HSN1 viruses were chosen to conduct next generation sequencing and hemagglutination inhibition （HI） assay. Results In total of 19 HSN1 virus strains were isolated, they were all from poultry related environments and collected in January-March of year 2013. Seven representative highly pathogenic avian influenza HSN1 viruses were sequenced and analyzed for antigenicity. According to phylogenetic analysis of HA gene, 6 viruses were belong to clade 2. 3.2. 1 c except A/Environment/Qinghai/XN02032/2013 which belongs to clade 7.2. Antigenic analysis showed that 6 viruses were antigenically similar to A/Barn swallow/Hang Kong/D10-1161/2010, while A/Environment/ Qinghai/XN02032/2013 presented low reaction with all reference antisera. Conclusions The existence of highly pathogenic avian influenza HSNlviruses in poultry related environments of surrounding areas of Qinghai Lake was confirmed. The status of highly pathogenic avian influenza H5N1 viruses with evolution diversity emphasized the necessary of strengthening the avian influenza surveillance in these areas.