IBV3株分离株的血清中和试验及S1基因同源性分析

Seroneutralization Test and Homology of S1 Gene Sequence of Threes Strains of Infectious Bronchitis Virus Isolated from China

通过血清中和试验、RT-PCR、核酸序列分析和S1基因的同源性分析,表明鸡传染性支气管炎病毒(IBV)BJ9601、HN9604与M41株的血清中和效价最高,其次为H120,TJ9602与试验毒株的血清中和效价较低。BJ9601、HN9604的S1基因与H120和H52的同源性很高,与H120和H52同在一个分支,其来源与H120或H52有密切关系。TJ9602的S1基因只与LDT3的同源性达到93%,共同形成一个分支,与其他毒株的同源性均在88%以下。血清中和试验和S1基因同源性之间存在较高的相关性,但并不能达到完全的吻合,即血清中和效价最高的毒株之间S1基因的同源性并不是最高的。在GenBank中登记的IBV中国大陆分离株的S1基因可分为3个基因群,其中Ⅰ群和Ⅱ群是主要的流行毒株,共有38个分离毒株,占90.48%。

Three strains of infectious bronchitis virus were isolated from chicken factories in China,which were TJ9602 strain and HN9604 strain and BJ9601 strain. Every virus strain was studied with seroneutralization test,RT-PCR for S1 gene, nucleic acid sequence analysis and homology analysis. The results showed that the seroneutralization titer of HN9604.strain and BJ9601 strain was the highest with M41 strain,and it was second with H120 strain. The seroneutralization titer of TJ9602 strain was very lower with every virus strain was tested. The source of S1 gene of HN9604 strain and BJ9601 strain had a strong affinity with H120 strain or H52 strain,because it was very high in homology of S1 gene sequence that HN9604 strain and BJ9601 strain were aligned with H120 strain and H52 strain separately,and they formed a similar phylogenetic tree with H120 strain and H52 strain. TJ9602 strain formed a similar phylogenetic tree with LDT3 strain,and the homology was 93% with LDT3 strain,but the homology was under 88% with other IBV strains. There were strong relativity about the seroneutralization test and the homology of S1 gene,but it was not complete consistency,because the seroneutralization titer was the highest but the homology of S1 gene sequence was not for the two IBV strains. There were 3 gene groups about S1 gene of all IBV strains isolated from China published in GenBank,and the gene group Ⅰ and Ⅱ were the chief IBV strain that had 38 IBV strains isolated from China ,and they were 90. 48%.