1株鸡H9亚型禽流感病毒的分离鉴定和HA基因序列分析

Identification of Avian Influence Virus H9 Subtype Isolated from Broiler and Analysis of HA Gene

关键词:  鸡  禽流感病毒  H9亚型  HA基因  

Key words:  Broiler  avian influence virus H9 subtype  HA gene  

摘要:

从广东珠三角地区某鸡场的发病肉鸡群采样,接种10日龄SPF鸡胚后分离到一株病毒,并命名为JL株,经微量血凝和微量血凝抑制检验为禽流感病毒H9亚型阳性。测序结果分析显示,HA蛋白裂解位点的氨基酸序列为RSSR↓GLF,与低致病性禽流感病毒的基序一致。HA基因分析结果表明,JL株属于4.2.5分支。BLAST结果显示,HA基因序列与RZ853株相似性最高,达97%。相似性比较结果表明,HA基因、蛋白与近年来国内流行的GX55等4.2.5分支H9亚型禽流感病毒相似性较高,分别为90.9%~97%和93.4%~99.5%,而与国内常用疫苗株SS、F、SD696等4.2.3分支H9亚型禽流感病毒相似性较低,分别为85.8%~88.1%和88.4%~89.1%。由此可见,分离的JL株属于4.2.5分支,与近年来国内流行株类似,并与常用疫苗株存在了一定的差异。

Abstract:

s: Some sick broiler sampled from Pearl River Delta region, inoculated with 10 day-old chicken embryos, and isolated a virus which was named JL. HA and HI tests result as avian influence virus H9 subtype positive. The result of sequence analysis showed that the amino-acid sequence of the haemagglutinin protein cleavage site was RSSR↓GLF, a typical sequence of lentogenic strains. Phylogenetic analysis showed that the strain belonged to clade 4.2.5. The result of BLAST showed that HA gene nucleotides of the strain were highest identities with the A/chicken/Rizhao/853/2013 H9N2 isolate, with 97%. And the homology analysis of HA gene nucleotides and protein amino acid showed that the isolate was high identities with the prevalent strains, such as GX55, with 90.9%~97% and 93.4%~99.5%, but low identities with the common vaccine strains, such as SS, F and SD696, only with 85.8%~88.1% and 88.4%~89.1%. Respectively, the strain belonged to clade 4.2.5, similar to the prevalent strains, which differed from the common vaccine strains belonged to clade 4.2.3.