Metwally Samy, Hamada Rania, Ali Alsagher O, Mahmoud Hassan Y A H, Baker Nabil M, Mohamed Adel E A, Wada Satoshi, Matsumoto Yasunobu, Aida Yoko
Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
J Vet Med Sci. 2020 Dec 5;82(11):1676-1684. doi: 10.1292/jvms.20-0477. Epub 2020 Oct 20.
Bovine leukemia virus (BLV) is the etiological agent of enzootic bovine leukosis, the most common neoplastic disease of cattle worldwide and a serious problem for the cattle industry. Previous studies have shown the molecular prevalence of BLV and the coexistence of BLV genotype-1 and -4 in Egyptian dairy cattle; however, the molecular characteristics of BLV in Egyptian beef cattle are unknown. Therefore, we collected blood samples of 168 beef cattle from slaughterhouses in three governorates in Egypt. Based on BLV-CoCoMo-qPCR-2 targeting long terminal repeats and nested PCR targeting the env-gp51 gene, the BLV provirus infection rates were found to be 47/168 (28.0%) and 42/168 (25.0%), respectively. Phylogenetic analysis based on 501 bp of the BLV env-gp51 gene from 42 BLV isolates revealed that at least six distinctive strains (b, e, f, g, x, and z) were prevalent in cattle across the examined regions. Furthermore, phylogenetic analysis of the 420 bp sequence of the BLV env-gp51 region of the six strains against 11 known genotypes showed that the strains b, e, f, and g were clustered into genotype-1, and strains x and z were clustered into genotype-4. Our results also indicated that strains b and x exist in both dairy and beef cattle in Egypt. The present study is the first to detect and genotype BLV among beef cattle in Egypt.
牛白血病病毒（BLV）是地方流行性牛白血病的病原体，是全球牛最常见的肿瘤性疾病，也是养牛业面临的一个严重问题。先前的研究表明，埃及奶牛中BLV的分子流行情况以及BLV基因型1和4的共存；然而，埃及肉牛中BLV的分子特征尚不清楚。因此，我们从埃及三个省的屠宰场采集了168头肉牛的血样。基于靶向长末端重复序列的BLV-CoCoMo-qPCR-2和靶向env-gp51基因的巢式PCR，发现BLV前病毒感染率分别为47/168（28.0%）和42/168（25.0%）。基于42株BLV分离株的BLV env-gp51基因501 bp进行系统发育分析，结果显示在所检测区域的牛中至少有六种不同的毒株（b、e、f、g、x和z）流行。此外，对这六种毒株的BLV env-gp51区域420 bp序列与11种已知基因型进行系统发育分析，结果表明毒株b、e、f和g聚类为基因型1，毒株x和z聚类为基因型4。我们的结果还表明，毒株b和x在埃及的奶牛和肉牛中均有存在。本研究首次在埃及肉牛中检测到BLV并对其进行基因分型。
