摘要
为了解近年来中国部分地区H9N2亚型禽流感病毒流行特点及遗传进化情况,利用RT-PCR方法扩增2012～2015年分离的17株H9N2亚型禽流感病毒的HA基因片段,并进行序列测定和遗传进化分析,同时对HA蛋白的裂解位点、受体结合位点和潜在的糖基化位点进行分析.结果显示,17株H9N2亚型禽流感病毒HA基因核苷酸和推导的氨基酸同源性分别为87％～100％和75％～100％,均属于Y280-1ike亚系毒株.HA基因裂解位点均为非连续碱性氨基酸,属于低致病力毒株.HA基因受体结合位点149、198、234和235位氨基酸存在变异,其中,16株分离毒株的234位氨基酸由Q突变为L,表现出人流感病毒受体结合特征.潜在糖基化位点分析结果显示,11株病毒在218位氨基酸处缺失1个糖基化位点,4株病毒在492位氨基酸处缺失1个糖基化位点,17株病毒在313位氨基酸处增加1个糖基化位点.研究结果表明,应加强对H9N2亚型AIV的流行病学监测,关注疫苗毒株与流行毒株的差异.
In order to study the epidemiology and genetic evolution characteristics of H9N2 subtype avain influenza virus （AIV） isolated from some areas of China,the hemagglutinin （HA） gene of 17 H9N2 subtype AIVs isolated from 2012 to 2015 were amplified by RT-PCR.Sequencing and phylogenetic analysis were performed,and the molecular characteristics of the motif of HA protein cleavage site,the receptor binding sites and potential glycosylation sites were analyzed.The results showed that the HA gene of 17 strains shared nucleotide and deduced amino acid homologies ranging from 87％ to 100％ and 75％ to 100％,respectively.All strains belonged to Eurasian lineage,Y280-like sublineage.The cleavage sites motif of 17 isolates lacked multiple basic amino acids,which made them low pathogenic strains.There were amino acid variations at sites 149,198,234 and 235 of the receptor binding sites,while 16 isolates had a leucine residue at site 234,indicative of the characteristics of human influenza virus-like receptor.The analysis results of potential glycosylation site indicated that a glycosylation site deletion took place at amino acid site 218 of 11 isolates and site 492 of 4 isolates,while an additional potential glycosylation site were found at amino acid site 313 of 17 isolates.In summary,the epidemiological investigation of H9N2 subtype AIV should be enhanced and the difference between isolated virus and vaccine virus should be paid more attention.
出处
《中国畜牧兽医》
CAS
北大核心
2016年第5期1148-1155,共8页
China Animal Husbandry & Veterinary Medicine
基金
广州市产学研协同创新重大专项(201508020088)
