Detection of natural inter- and intra-genotype recombination events revealed by cap gene analysis and decreasing prevalence of PCV2 in wild boars
Detection of natural inter- and intra-genotype recombination events revealed by cap gene analysis and decreasing prevalence of PCV2 in wild boars
复制标题
DOI：
10.1016/j.meegid.2012.01.014
复制
发表时间：
2012-03-01
影响因子：
3.2
通讯作者：
Tuboly, Tamas
中科院分区：
文献类型：
--
作者：
Cadar, Daniel;Csagola, Attila;Tuboly, Tamas
猪圆环病毒2型（Porcine circovirus type 2，PCV 2）广泛存在于家猪和野猪中，是引起猪圆环病毒相关疾病（Porcine circovirus associated diseases，PCVAD）的主要病原。本研究利用重组检测程序，对来自跨西尔瓦尼亚野猪的28个PCV 2 ORF 25（衣壳蛋白编码基因）和来自特兰西瓦尼亚家猪的8个ORF 25（衣壳蛋白编码基因）进行了系统发育分析和碱基比较，检测了最近发生的基因型内（PCV 2b-1B/PCV 2b-1C）和基因型间（PCV 2a-2D/PCV 2b-1C）重组事件。值得注意的是，在家猪中检测到一种潜在的重组体（F1-21），可能具有野猪来源的亲本菌株。估计的重组断裂点包括ORF 2的表位A、B和C，氨基酸序列没有重大变化。在罗马尼亚家猪首次爆发断奶后多系统衰竭综合征（PMWS）后的5年期间，野猪种群中PCV 2的患病率从13.4%下降到8.3%。据我们所知，这是第一个研究表明存在的ORF 2为基础的基因型内和基因型间的重组在野猪种群和野猪和家猪的PCV 2株之间的可能重组。我们的研究结果表明，在野猪种群中PCV 2感染具有一定的独立性，并证明了在自然环境下感染多种PCV 2基因型的可能性。另一方面，在家猪中可以以较低的频率检测到野猪特异性的PCV 2基因型，这表明野猪PCV 2可能传播到家猪。本文描述的重组事件可能有助于PCV 2的遗传多样性，也可能是新PCV 2毒株出现的根源。(C)2012爱思唯尔有限公司版权所有。
Porcine circovirus type 2 (PCV2), the causative agent of a number of PCVAD (porcine circovirus associated diseases), is ubiquitous in domestic pig and wild boar populations. In the present study, using recombination detection program, phylogenetic analysis and base-by-base comparison of 28 PCV2 ORF25 (capsid protein coding gene) from wild boars and 8 from domestic pigs of Transylvania, recent natural intra- (PCV2b-1B/PCV2b-1C) and inter-genotype (PCV2a-2D/PCV2b-1C) recombination events were detected. Notably, one potential recombinant (F1-21) was detected in domestic pig with possible parental strains of wild boar origin. The estimated recombinant breakpoints comprised epitopes A, B and C of ORF2, without major changes in amino acid sequences. The prevalence of PCV2 in the wild boar population during the 5-year period following the first outbreaks of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs in Romania showed a decrease from 13.4% to 8.3%. To our knowledge, this is the first study to show the existence of ORF2-based intra- and inter-genotype recombination in wild boar populations and the possible recombination between PCV2 strains of wild boars and domestic pigs. Our results suggest a certain independence of PCV2 infection in wild boar populations and demonstrate the possibility of infection with multiple PCV2 genotypes under natural circumstances. On the other hand, PCV2 genotypes specific for wild boars could be detected in domestic pig at lower frequency suggesting the possible spread of wild boar PCV2 to domestic swine. The recombination events described here may contribute to the genetic diversity of PCV2 and may also be the source of emergence of new PCV2 strains. (C) 2012 Elsevier B.V. All rights reserved.