牛病毒性腹泻病毒BVDV-LC株的分离与鉴定

Isolation and identification of a bovine viral diarrhea virus strain LC

为分离鉴定新疆地区牛病毒性腹泻病毒(BVDV)流行株,本研究通过RT-PCR检测、细胞分离培养、直接免疫荧光抗体检测、核苷酸序列测定及生物信息学分析对新疆某奶牛场采集的腹泻牛粪便样品进行了病毒分离和鉴定。结果显示,分离得到一株新的牛源BVDV,命名为BVDV-LC株。该病毒株在MDBK细胞培养时未能引起细胞病变;5'-UTR与N^(pro) PCR扩增为阳性,扩增片段与预期大小一致;直接免疫荧光检测荧光信号为阳性;病毒滴度为10^(5.6) TCID_(50)/0.1 mL;遗传进化分析显示,该分离株与猪源BVDV-SD0803株有较近的亲缘关系,同属于BVDV-1q基因亚型。本研究表明BVDV-LC株的分离鉴定对进一步开展疫苗研发、牛病毒性腹泻致病机理等方面的研究具有重要意义。

In the present study, a virus was isolated from faeces samples of cattle with bovine viral diarrhea like syndrome in a dairy farm in Xinjiang area, and identificated by RT-PCR, cell culture, direct immunofluorescent assay, nucleotide sequencing and bioinformatics analysis. The results showed that the virus isolate was bovine viral diarrhea virus （BVDV） and designated BVDV-LC. Although the virus was unable to produce cytopathic effect （CPE） in MDBK cells, it was capable to replicate efficiently in MDBK with a virus titer of 105.6 TCID50/0.1 mL detected by PCR amplification of the 5＇-UTR and N^pro, or direct immunofluorescent assay. Phylogenetic analysis indicated that the isolate was close to BVDV-SD0803 of swine origin, both of which belonged to BVDV-lq gene subtype. The isolation and identification of BVDV-LC strain was of great value to the vaccine development and the study of bovine viral diarrhea.