【摘要】 为了解宁夏地区牛病毒性腹泻病毒（BVDV）的分子流行病学现状及其N^pro基因的遗传变异情况，从宁夏某牛场疑似感染BVDV的9份牛血清中分离到1株可导致细胞发生病变的BVDV毒株，命名为BVDV NX-01,通过测定病毒滴度、电镜观察、病毒N^pro基因扩增及测序、绘制进化树、序列一致性比对等方法，对分离株进行鉴定及遗传进化分析。结果：该分离株接种MDBK细胞培养可产生明显的细胞病变，培养48 h病毒滴度达10^7.0 TCID₅₀/0.1 mL,病毒粒子呈有囊膜的球形，直径40～60 nm;进化分析结果表明，BVDV NX-01与GS2018株有较近的亲缘关系，同属于BVDV-2a基因亚型；序列一致性比对发现，BVDV NX-01与进化树中处于同一分支的GS2018株N^pro基因一致性高达98.9%,进一步说明分离株BVDV NX-01属于BVDV-2a亚型。本研究结果不仅丰富了宁夏地区BVDV的分子流行病学数据，也为从分子水平研究BVDV的致病机理提供一定的理论依据。更多还原

【Abstract】 To understand the molecular epidemiological status of bovine viral diarrhea virus（BVDV） and its genetic variation of the N^pro gene in the Ningxia area, a strain of BVDV（BVDV NX-01）, which causes cellular lesions, was isolated from nine cattle serum samples suspected to be infected with BVDV in a cattle farm in Ningxia in this study. The isolate was also identified and analyzed for genetic evolution by measuring the titer of the virus, and using electron microscopy, and by amplifying and sequencing the viral N^pro gene, mapping its evolutionary tree, and comparing the sequence identity of the gene. The results showed that the isolate produced obvious cytopathic lesions when inoculated with MDBK cells, and its viral titer reached 10^7.0 TCID₅₀/0.1 mL at 48 h. The particles of the virus were spherical with a vesicular membrane and a diameter of about 40-60 nm. The sequence identity comparison showed that BVDV NX-01 was 98.9% identical to the Npro gene of the GS2018 strain, which was in the same branch of the evolutionary tree, further indicating that the isolate BVDV NX-01 belonged to the BVDV-2 a subtype. The successful isolation of the CP-type BVDV-2 a subtype strain in this study not only enriched the molecular epidemiological data of BVDV in the Ningxia area, but also offered theoretical support for studying the pathogenesis of BVD at the molecular level.更多还原