鸡传染性支气管炎病毒ck/CH/LHB/100801株的分离鉴定及分子特征研究

摘要

本研究于2010年8月从河北省某鸡场鸡群中分离一株病毒,通过对分离株进行电子显微镜观察、鸡胚致病性试验、血凝特性试验等生物学特性及鸡传染性支气管炎病毒(IBV)核蛋白基因RT-PCR方法鉴定,结果表明分离株为IBV,命名为ck/CH/LHB/100801.根据GenBank中登录的IBV基因组序列,设计扩增病毒全基因组的19对引物,并扩增病毒基因组,采用3-RACE和5-RACE技术,扩增得到该病毒全部基因组序列.通过与已发表的参考病毒株全基因组序列比较表明,该分离株基因组全长为27 675bp,共有10个开放阅读框,其基因排序为:5'-cap-Replicase-S-3a-3b-3c-M-5a-5b-N-poly(A)-3',纤突蛋白裂解位点为534RRFRR538.序列分析表明ck/CH/LHB/100801与台湾分离株TW2296/95的结构蛋白序列相似性高达99.8%,进化亲缘关系最近,推测两分离株间可能具有相同的进化来源.%An isolate of avian infectious bronchitis virus (IBV), designated ck/CH/LHB/100801), was isolated from Hebei area of China in 2010 and identified by electron microscope observation, pathogenicity to chicken embryo, hemagglutination test and RT-PCR. The complete genome was cloned by RT-PCR and sequenced including 3′- and 5′-terminals with 19 pairs of primers according to the genome sequences of IBV in GenBank. The sequences analysis showed that the 27,675 bp of ck/CH/LHB/100801 had the 5′-cap-Replicase-S-3a-3b-3c-M-5a-5b-N-poly (A)-3′ gene order, and the typical avian coronavirus cleavage site of 534RRFRR538 in spike protein. The ck/CH/LHB/100801 isolate shared 99.8％ similarity of structure protein encoding sequence with TW2296/95 strain isolated in Taiwan. Therefore, we speculated that ck/CH/LHB/100801 isolate might derivated from the TW2296/95 strains due to point mutations.