Molecular evolution of PRRSV in Europe: Current state of play
Molecular evolution of PRRSV in Europe: Current state of play
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DOI：
10.1016/j.vetmic.2013.02.029
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发表时间：
2013-07-26
影响因子：
3.3
通讯作者：
Oleksiewicz, Martin B.
中科院分区：
文献类型：
--
作者：
Stadejek, Tomasz;Stankevicius, Arunas;Oleksiewicz, Martin B.
猪繁殖与呼吸综合征病毒（PRRSV）是欧洲猪生产的主要威胁。地方性毒株中广泛存在的遗传变异和其他地理区域中存在的高毒力毒株构成了毁灭性流行病爆发的威胁。在这里，我们描述了目前对欧洲PRRSV分离株遗传变异的了解，对PRRSV进化的影响，以及欧洲2型（北美基因型）分离株多重遗传谱系的存在。在1型（欧洲基因型）PRRSV中，可以识别出三种遗传亚型，并且似乎存在第四种亚型。2型PRRSV在欧洲被认为是遗传同质的，这是由于一种引入的疫苗株的独特存在，但现在明显存在独立引入的毒性2型田间病毒。在1型PRRSV中，只有1亚型（Lelystad病毒样）在中欧、西欧和全球传播。在东欧，所有亚型都存在。1型PRRSV亚型在核衣壳蛋白上也表现出长度差异，根据亚型的不同，其大小从124到132个氨基酸不等。这种大小的异质性在2型PRRSV或其他病毒的核衣壳蛋白中是无与伦比的。令人惊讶的是，它影响到c端，否则被认为是在很强的结构约束下。最后，1型PRRSV的不同亚型在诊断试验中产生了很高的RT-PCR假阴性结果，也可能降低使用核衣壳蛋白抗原进行血清诊断分析的可靠性。总之，1型PRRSV广泛的遗传多样性对理解核衣壳蛋白结构/功能关系具有重要意义。此外，1型PRRSV在欧洲广泛的遗传多样性，以及2型PRRSV菌株的存在，共同强调了PRRSV诊断相关验证的重要性。需要进行更广泛和系统的分子系统发育研究，以充分了解欧洲PRRSV的多样性，为养猪生产者提供可靠的诊断，并更好地评估地方性传播和外来引入的潜在后果。(C) 2013 Elsevier B.V.版权所有
Porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to European swine production. The existence of extensive genetic variation in endemic strains and the presence of highly virulent strains in other geographic regions pose the threat of devastating epidemic outbreaks. Here we describe the current knowledge of genetic variation in European PRRSV isolates, the implications for PRRSV evolution, and the presence of multiple genetic lineages of Type 2 (North American genotype) isolates in Europe. In Type 1 (European genotype) PRRSV, three genetic subtypes are recognized and a fourth subtype appears to be present. Type 2 PRRSV was considered to be genetically homogenous in Europe due to a unique presence of an introduced vaccine strain, but independent introductions of virulent Type 2 field viruses are now evident. In Type 1 PRRSV, only subtype 1 (Lelystad virus-like) circulates in Central and Western Europe and globally. In Eastern Europe, all subtypes are present. The subtypes of Type 1 PRRSV also exhibit length differences in the nucleocapsid protein, ranging in size from 124 to 132 amino acids depending on subtype. This size heterogeneity is unparalleled in the nucleocapsid proteins of Type 2 PRRSV or other viruses. Surprisingly, it affects the C-terminus, otherwise thought to be under strong structural constraints. Finally, divergent subtypes of Type 1 PRRSV have produced high rates of false-negative RT-PCR results in diagnostic tests, and may also degrade the reliability of serodiagnostic assays using the nucleocapsid protein antigen. In summary, the extensive genetic diversity of Type 1 PRRSV is of relevance for understanding nucleocapsid protein structure/function relationships. Further, the extensive genetic diversity of Type 1 PRRSV in Europe, and the presence of diverse Type 2 PRRSV strains, together emphasize the importance of relevant validation of PRRSV diagnostics. More extensive and systematic molecular phylogeny studies are needed to fully understand PRRSV diversity in Europe, to provide swine producers with reliable diagnostics, and to better assess the potential consequences of endemic spread and exotic introductions. (C) 2013 Elsevier B.V. All rights reserved.