Molecular epidemiological and serological studies of bovine leukemia virus (BLV) infection in Thailand cattle
Molecular epidemiological and serological studies of bovine leukemia virus (BLV) infection in Thailand cattle
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DOI：
10.1016/j.meegid.2016.04.010
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发表时间：
2016-07-01
影响因子：
3.2
通讯作者：
Shin, Yeun-Kyung
中科院分区：
文献类型：
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作者：
Lee, EunJung;Kim, Eun-Ju;Shin, Yeun-Kyung
BLV 是地方性牛白血病的病原体。 BLV 对动物健康产生负面影响，并在全球范围内造成经济损失。然而，在亚洲国家的许多地区，BLV的流行病学研究相对较少。因此，本研究试图探索泰国牛的 BLV 感染情况，以确定 BLV 的地理分布范围并测量其患病率。本研究于 2013 年和 2014 年通过 ELISA 和巢式 PCR 对来自泰国 9 个省份 11 个农场的 744 头牛进行了筛查。使用 GenBank 中提供的 188 个 BLV gp51 env 基因序列对这些牛中的 41 个 BLV 进行了遗传表征。泰国的 BLV 患病率很高，根据地理区域，PCR 测定为 5.3% 至 87.8%，ELISA 测定为 11.0% 至 100%。系统发育分析显示，泰国BLV属于基因型1和6以及新的基因型10，这两种基因型在泰国各地零星观察到，患病率分别为31.7%、19.5%和48.8%。在 gp51 序列中还发现了大量氨基酸取代，其中基因型 10 的独特变化以前从未报道过。简而言之，大多数替换仅限于 CD4+/CD8+ T 细胞表位、中和结构域和 E-D-A 表位。这些观察结果表明，泰国牛中 BLV 感染很普遍，而且 BLV 的地理分布是动态的，具有高度的遗传多样性。这种分布意味着牛群中存在长期 BLV 感染以及受感染牛的移动。总之，本研究表明需要加强监测和有效的预防策略来确定泰国 BLV 的流行情况并控制 BLV 的持续感染。 (C) 2016 Elsevier B.V. 保留所有权利。
BLV is the etiological agent of enzootic bovine leucosis. BLV has negative effects on animal health and causes economic losses worldwide. However, epidemiological studies on BLV are relatively unknown in many parts of Asian countries. Thus, this study sought to explore BLV infections in cattle in Thailand to determine the extent of the geographic distribution of BLV and to measure its prevalence rates. For this study, 744 cattle from 11 farms in 9 provinces of Thailand were screened in 2013 and 2014 by ELISA and nested PCR. Of those cattle, 41 BLVs were genetically characterized using 188 BLV gp51 env gene sequences available in GenBank. The BLV prevalence in Thailand was high, ranging from 5.3% to 87.8%, as determined by PCR and 11.0% to 100% as determined by ELISA, according to geographical region. Phylogenetic analysis showed that Thailand BLVs belonged to genotypes 1 and 6 and a new genotype 10, which are sporadically observed across Thailand with a prevalence of 31.7%, 19.5%, and 48.8%, respectively. A significant number of amino acid substitutions were also found in the gp51 sequences, of which unique changes in genotype 10 have not been reported previously. Briefly, the majority of substitutions were confined to CD4+/CD8+ T-cell epitopes, neutralizing domains, and E-D-A epitopes. Those observations indicate that BLV infections in Thailand cattle are prevalent and that the geographic distribution of BLV is dynamic, with a high level of genetic diversity. This distribution implies a long-term BLV infection in cattle populations and the movement of infected cattle. In sum, this study suggests that intensive surveillance and effective prevention strategies are required to determine the prevalence of BLV in Thailand and control continuous infections with BLVs. (C) 2016 Elsevier B.V. All rights reserved.