传染性支气管炎病毒广西分离株S1基因高变区Ⅰ的序列分析

Sequence analysis of S1 gene hypervariable region Ⅰ of IBV strains isolated in Guangxi

对7个传染性支气管炎病毒广西分离株的S1基因高变区Ⅰ(HVRⅠ)进行RT-PCR扩增和序列分析,并用DNA star软件将这7个分离毒株与我国常用疫苗毒株、国际上其他血清型的代表参考毒株分别进行核苷酸和氨基酸系统发生进化关系分析。核苷酸与氨基酸序列分析结果表明:7个广西分离毒株可形成2个分支,第1分支与疫苗株H 120、H 52、M a5和参考株M 41、B eaudette的亲缘关系较近,第2分支则与疫苗株H 120、H 52、M a5的亲缘关系较远,但与欧洲分离株4/91的亲缘关系较近。结果提示广西的流行毒株变异较大,实际免疫中要根据流行毒株的特性来生产和选择合适的疫苗株。

S1 gene hypervariable region Ⅰ （HVR Ⅰ ） of 7 strains of infectious bronchitis virus （IBV） isolated in Guangxi were amplified by using a RT-PCR technique and the cDNA sequences of those strains were determined. Phylogenetic relations based on the nucleotide and amino acid sequences were analyzed among Guangxi isolates and the reference strains in GenBank by using DNAstar software. The isolates could be divided into 2 groups： isolates in group Ⅰ had close relationship with the traditional IBV vaccine strains H120, H52, Ma5 and reference strains M41 and Beaudette; isolates in group Ⅰ had less relationship with the vaccine strains, but showed a closer phylogenetic relationship with the European isolate 4/91. The results demonstrated that there was a high variability among the IBV isolates in Guangxi, and the development and the applications of the vaccines should be based on the molecular characterization of the local strains.