Phylogenetic networks to study the origin and evolution of porcine circovirus type 2 (PCV2) in Cuba
Phylogenetic networks to study the origin and evolution of porcine circovirus type 2 (PCV2) in Cuba
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DOI：
10.1016/j.vetmic.2011.03.022
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发表时间：
2011-08-05
影响因子：
3.3
通讯作者：
Nunez, Jose I.
中科院分区：
文献类型：
--
作者：
Perez, Lester J.;Diaz de Arce, Heidy;Nunez, Jose I.
猪圆环病毒2型（Porcine circovirus type 2，PCV 2）是断奶后多系统衰竭综合征（postweaning multisystemic wasting syndrome，PMWS）的主要病原。在这项研究中，比较基于经典系统发育树和网络的方法来推断PCV 2在古巴的起源。此外，还研究了支持古巴PCV 2群体遗传变异性的机制。还使用1993年至2004年在古巴收集的猪血清进行了一项回顾性研究，以评估PCV 2基因组和PCV 2特异性抗体的存在，并发现1993年至2004年古巴猪中缺乏PCV 2感染的证据。共分析了2005年至2009年期间从该国不同地区收集的24个完整的古巴PCV 2序列。系统发育分析的三个经典方法，即邻连接，最大简约和贝叶斯推理，以及单倍型网络的构建，被使用。而经典的系统发育树表明古巴PCV 2株的不同起源，单倍型网络显示所有古巴序列之间的直接联系与获得的流行病学和病毒序列数据一致。此外，2005年从加拿大魁北克-安大略地区进口猪似乎是古巴二型多氯联苯病毒最有可能的来源。同样，古巴PCV 2序列的遗传变异性得到了地理分离和正选择压力的支持，估计核苷酸替换率约为3.12 x 10（-3）和6.57 x 10（-3）替换/位点/年，这更接近RNA病毒的报告。(C)2011爱思唯尔有限公司版权所有。
Porcine circovirus type 2 (PCV2) is the essential etiological infectious agent of postweaning multisystemic wasting syndrome (PMWS), which is considered one of the most economically important swine diseases worldwide. In this study, a comparison between methodologies based on classical phylogenetic trees and networks to infer the origin of PCV2 in Cuba was performed. In addition, the mechanisms supporting the genetic variability of Cuban PCV2 populations were investigated. A retrospective study, using pig sera collected in Cuba from 1993 to 2004, to evaluate the presence of PCV2 genome and PCV2-specific antibodies was also conducted and revealed a lack of evidence of PCV2 infection in Cuban swine from years 1993 to 2004. A total of 24 complete Cuban PCV2 sequences collected between 2005 and 2009 from different regions of the country were analyzed. Three classical methods of phylogenetic analysis, namely Neighbour-Joining, Maximum Parsimony and Bayesian Inference, as well as haplotype network construction, were used. Whereas the classical phylogenetic trees suggested different origins for the Cuban PCV2 strains, the haplotype network revealed a direct connection between all the Cuban sequences in agreement with the obtained epidemiological and viral sequence data. Moreover, the importation of pigs carried out in 2005 from the Quebec-Ontario region, Canada, seems to be the most likely origin of PCV2 in Cuba. Likewise, the genetic variability of Cuban PCV2 sequences was supported by geographic segregation and positive selection pressure with estimated rates of nucleotide substitution on the order of 3.12 x 10(-3) and 6.57 x 10(-3) substitutions/site/year, which are closer to those reported for RNA viruses. (C) 2011 Elsevier B.V. All rights reserved.