鸡传染性支气管炎病毒HH06分离株的鉴定及其S1基因的分子特征

Identification of avian infectious bronchitis virus HH06 and molecular characteristics of its S1 gene

从黑龙江省哈尔滨市某鸡场疑似鸡传染性支气管炎的发病蛋鸡肾组织病料中分离到1株病毒,命名为HH06。该分离毒株经SPF鸡胚传代、血凝试验、负染电镜检查以及动物回归试验,证实为IBV。用RT-PCR扩增得到了HH06株S1基因片段,经测序,并与国内外IBV参考毒株的相应基因进行序列比较分析。结果表明,HH06株S1基因由1 620个核苷酸组成,推导的多肽由540个氨基酸残基组成,推导的氨基酸裂解位点序列为5个连续碱性氨基酸HRRRR。HH06株S1基因序列与除LX4外的其他参考株相应基因的核苷酸及氨基酸序列同源性均较低,亲缘关系均较远。初步证实HH06株为不同于IBV疫苗株的一个新毒株。

A novel strain of avian infectious bronchitis virus （IBV）, HH06, was identified in the kidney in hens suspected of avian infectious bronchitis （IB） in a flock in Heilongjiang Province, China. The strain was passaged in SPF chicken embryos and characterized by electron microscope, and HA experi- ment, and infection potency in vivo. Sequences of S1 genes of IBV HH06 and 13 reference IBV strains from GenBank were compared. Results showed that the HH06 S1 gene consisted of 1620 nt and encoded a polypeptide of 540 amino acids. The cleavage site sequence of S1 protein of HH06 strain appeared to con-tain 5 consecutive basic amino acids, HRRRR. Sequence analysis, along with the topology of the S1 pro-tein based phylogenetic tree, suggested that the HH06 strain was a novel IBV strain. HH06 apparently differed from these conventional strains used for vaccine production.