Institut des Siences de l'Evolution de Montpellier, UMR226 IRD-CNRS-UM2, 361 Rue Jean-François Breton, BP5095, 34196 Montpellier Cedex 05, France.
J Virol Methods. 2011 May;173(2):320-7. doi: 10.1016/j.jviromet.2011.03.002. Epub 2011 Mar 8.
Cyprinid herpesvirus-3 (CyHV-3), or koi herpesvirus (KHV), is responsible for high mortalities in aquaculture of both common carp (Cyprinus carpio carpio) and koi carp (Cyprinus carpio koi) worldwide. The complete genomes of three CyHV-3 isolates showed more than 99% of DNA sequence identity, with the majority of differences located in short tandem repeats, also called VNTR (variable number of tandem repeats). By targeting these variations, eight loci were selected for genotyping CyHV-3 by multiple locus VNTR analysis (MLVA). CyHV-3 strains obtained after sequential in vivo infections exhibited identical MLVA profiles, whereas samples originating from a single isolate passaged 6 and 82 times in vitro exhibited mutations in two of the eight loci, suggesting a relatively slow genetic evolution rate of the VNTRs. The method was subsequently applied on 38 samples collected in Indonesia, France and the Netherlands. Globally, the isolates grouped in two main genetic clusters, each one divided in two subgroups including either CyHV-3-U/I or CyHV3-J. Interestingly, Indonesian strains were rather distant from CyHV-3-J isolate. The results of the present study indicate that these VNTR molecular markers are efficient in estimating the genetic diversity among CyHV-3 isolates and are therefore suitable for further molecular epidemiological studies.
鲤鱼疱疹病毒 3 型（CyHV-3），又称锦鲤疱疹病毒（KHV），是导致世界范围内鲤鱼（Cyprinus carpio carpio）和锦鲤（Cyprinus carpio koi）养殖业高死亡率的罪魁祸首。三种 CyHV-3 分离株的完整基因组显示出超过 99%的 DNA 序列同一性，大多数差异位于短串联重复序列，也称为 VNTR（可变数量串联重复序列）。通过针对这些变化，选择了 8 个基因座，通过多位点 VNTR 分析（MLVA）对 CyHV-3 进行基因分型。在体内连续感染后获得的 CyHV-3 株显示出相同的 MLVA 图谱，而来自单个分离株的样本在体外传代 6 和 82 次后，在 8 个基因座中的 2 个发生突变，表明 VNTR 的遗传进化速度相对较慢。该方法随后应用于在印度尼西亚、法国和荷兰收集的 38 个样本。在全球范围内，分离株分为两个主要的遗传群，每个群分为包括 CyHV-3-U/I 或 CyHV3-J 的两个亚群。有趣的是，印度尼西亚的菌株与 CyHV-3-J 分离株相距甚远。本研究的结果表明，这些 VNTR 分子标记可有效估计 CyHV-3 分离株之间的遗传多样性，因此适合进一步的分子流行病学研究。
