Volpe E, Grodzki M, Panzarin V, Guercio A, Purpari G, Serratore P, Ciulli S
Department of Veterinary Medical Sciences, University of Bologna, Cesenatico, Forlì-Cesena, Italy.
Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.
J Fish Dis. 2018 Apr;41(4):603-611. doi: 10.1111/jfd.12759. Epub 2017 Dec 5.
Betanodaviruses are small ssRNA viruses responsible for viral encephalopathy and retinopathy, otherwise known as viral nervous necrosis, in marine fish worldwide. These viruses can be either horizontally or vertically transmitted and have been sporadically detected in invertebrates, which seem to be one of the possible viral sources. Twenty-eight new betanodavirus strains were retrieved in three molluscs species collected from different European countries between 2008 and 2015. The phylogenetic analyses revealed that strains retrieved from bivalve molluscs are closely related to viruses detected in finfish in Southern Europe in the period 2000-2009. Nevertheless, a new betanodavirus strain, markedly different from the other members of the RGNNV genotype, was detected. Such a massive and varied presence of betanodaviruses in bivalve molluscs greatly stresses the risks of transmission previously feared for other invertebrates. Bivalve molluscs reared in the same area as farmed and wild finfish could act as a reservoir of the virus. Furthermore, current European regulations allow relaying activities and the sale of live bivalve molluscs, which could pose a real risk of spreading betanodaviruses across different geographic regions. To our knowledge, this is the first study, which focuses on the detection and genetic characterization of betanodaviruses in bivalve molluscs.
β-诺达病毒是一种小的单链RNA病毒，在全球范围内导致海水鱼类发生病毒性脑病和视网膜病，即病毒性神经坏死。这些病毒可通过水平或垂直方式传播，并且已在无脊椎动物中偶尔检测到，无脊椎动物似乎是可能的病毒来源之一。2008年至2015年期间，在从不同欧洲国家采集的三种软体动物物种中检索到28种新的β-诺达病毒株。系统发育分析表明，从双壳类软体动物中检索到的毒株与2000年至2009年期间在南欧有鳍鱼类中检测到的病毒密切相关。然而，检测到一种明显不同于RGNNV基因型其他成员的新型β-诺达病毒株。双壳类软体动物中β-诺达病毒如此大量且多样的存在极大地凸显了之前担心的其他无脊椎动物传播风险。与养殖和野生有鳍鱼类在同一区域养殖的双壳类软体动物可能充当病毒的储存库。此外，目前欧洲的法规允许进行暂养活动和销售活双壳类软体动物，这可能会造成β-诺达病毒在不同地理区域传播的实际风险。据我们所知，这是第一项专注于双壳类软体动物中β-诺达病毒检测和基因特征分析的研究。
