摘要： 应用ST细胞,从临床上表现为腹泻症状的病死仔猪肠内容物中分离得到一株病毒,并对该病毒进行RTPCR,直接免疫荧光与动物回归等试验,证实该病毒为猪传染性胃肠炎病毒(TGEV),命名为JS2012株。应用PCR方法克隆出其初代(P1TS)与50代(P50TS)的S基因片段,进行序列测定,并将该基因序列与已发表的18个不同来源的TGEV毒株进行同源性和亲缘关系的比较分析。结果表明,各毒株间核苷酸同源性为96.0%～99.9%,氨基酸的同源性为96.5%～99.9%。TGEVJS201PITS株与中国江苏省HN2002株和美国Miller M6亲缘较近,表明不同地区分离毒株的S基因差异不大,而与P1TS相比,P50TS的S基因在1 124～1 129位置有6个碱基的缺失,对比发现,这种变异接近于弱毒株Purdue P115株所发生的变异,提示所发生的缺失可能与病毒毒力的减弱相关。

关键词: TGEV, 分离鉴定, S基因, 序列分析, 缺失

Abstract: By serial passaging on ST cells,a transmissible gastroenteritis virus (TGEV)strain(TGEV JS2012)was obtained from intestinal contents of died piglets with clinical diarrhea symptom. This virus was proved to be TGEV by RT-PCR,direct immunofluorescence and animal regression test. The S gene of TGEV JS2012 strain primary aassages (P1TS)and the fiftith passages(P50TS),were amplified by PCR and then sequenced. Comparison of the S gene se-quences of P1TS and P50TS with 18 published TGEV strains with different origins showed that they can share 96.0%-99.9%homology of nucleotide sequences and 96. 5%-99. 9%homology of amino acids. Furthermore,the results of the phylogenetic tree analysis demonstrated that there was a close genetic relationship between P 1 TS strain and HN2002 or Miller M6 strain isolated from China and America respectively. Generally the result indicated the varia-tion of S gene between strains of different origins was not so obvious. The result also showed that a deletion of six bases happened in 1 124-1 129 location of the S gene of P50TS seemed to be similar to Purdue P115 strain which is an attenuated strain,indicating this deletion perhaps is related to the reduced virulence of TGEV.

Key words: TGEV, Isolation and identification, S Complete genome, Sequence analysis, Deletion

中图分类号: 

• S852.65