Baule C, van Vuuren M, Lowings J P, Belák S
Swedish University of Agricultural Sciences, Veterinary Faculty, Department of Veterinary Microbiology, Uppsala.
Virus Res. 1997 Dec;52(2):205-20. doi: 10.1016/s0168-1702(97)00119-6.
Seventy three field isolates of bovine viral diarrhoea virus (BVDV), obtained from cattle in Mozambique and South Africa, were characterised by comparative nucleotide sequence analysis of part of the 5' non-coding region (5'NCR) of the viral genome. The target region was amplified by reverse transcription-polymerase chain reaction (RT-PCR). The amplicons were cloned in pUC 19 plasmid and both strands were sequenced by T7 polymerase dideoxynucleotide chain-termination sequencing or directly by cycle sequencing. The 245 base pair (bp) nucleotide sequences, derived from the 5'NCR, were aligned and compared to the corresponding positions of published sequences of BVDV type I and II strains and of pestiviruses of ovine and porcine origin. The phylogenetic trees, generated from those comparisons, allowed the Southern African isolates to be assigned to two main groups within the BVDV I genotype. Group A could be subdivided into three clusters, two of which grouped with BVDV strains of European and American origin. The third cluster did not group with any known BVDV I strains and it was confirmed in a comparison from the NS3 coding region. Group B contained more divergent isolates which differed by 18-23%, from BVDV I reference strains NADL, Osloss and SD-1 and comprised another distinct subset within the BVDV I genotype. This grouping was consistent in a comparison involving the NS2-NS3 region. It was concluded that BVD viruses occurring in Southern Africa are genetically diverse, comprising different variants within the BVDV I genotype. They include viruses similar to BVDVs found in Europe and America and others apparently rare or absent in those continents, termed here as BVDV Ic and Id. The co-existence of BVDV strains of European and American origin in certain areas both in Mozambique and South Africa, indicates a probable introduction of those viruses through imports of cattle or through potentially infectious bovine products. In addition, the detection of isolates apparently rare or absent from Europe and America may indicate the presence of African variants of BVDV I (Pestivirus 1).
从莫桑比克和南非的牛身上分离得到73株牛病毒性腹泻病毒（BVDV）野毒株，通过对病毒基因组5'非编码区（5'NCR）部分序列进行比较核苷酸序列分析来进行特征鉴定。目标区域通过逆转录聚合酶链反应（RT-PCR）进行扩增。扩增产物克隆到pUC 19质粒中，两条链通过T7聚合酶双脱氧核苷酸链终止测序或直接通过循环测序进行测序。从5'NCR获得的245个碱基对（bp）的核苷酸序列进行比对，并与已发表的BVDV I型和II型毒株以及绵羊和猪源瘟病毒序列的相应位置进行比较。根据这些比较生成的系统发育树，可将南部非洲分离株归为BVDV I基因型内的两个主要组。A组可细分为三个簇，其中两个簇与欧洲和美洲来源的BVDV毒株聚在一起。第三个簇未与任何已知的BVDV I毒株聚在一起，并且在NS3编码区的比较中得到证实。B组包含更多差异较大的分离株，与BVDV I参考毒株NADL、Osloss和SD-1的差异为18% - 23%，在BVDV I基因型内构成另一个独特的亚组。在涉及NS2 - NS3区域的比较中，这种分组是一致的。得出的结论是，在南部非洲出现的BVD病毒在基因上具有多样性，包括BVDV I基因型内的不同变体。它们包括与在欧洲和美洲发现的BVDV相似的病毒，以及在那些大陆显然罕见或不存在的其他病毒，在此称为BVDV Ic和Id。在莫桑比克和南非的某些地区，欧洲和美洲来源的BVDV毒株共存，表明这些病毒可能是通过进口牛或潜在感染性牛产品引入的。此外，检测到在欧洲和美洲显然罕见或不存在的分离株，可能表明存在BVDV I（瘟病毒1）的非洲变体。
