Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), Laboratoire de Génétique et Pathologie (LGP), 17390 La Tremblade, France.
Vet Res. 2011 Feb 7;42(1):27. doi: 10.1186/1297-9716-42-27.
In 2008 and 2009, acute mortalities occurred in France among Pacific cupped oyster, Crassostrea gigas, spat. Different hypothesis including the implication of environmental factors, toxic algae and/or pathogens have been explored. Diagnostic tests indicated that OsHV-1 including a particular genotype, termed OsHV-1 μVar, was detected in most of samples and especially in moribund oysters with the highlighting of virus particles looking like herpes viruses by TEM examination. In this study, an experimental protocol to reproduce OsHV-1 infection in laboratory conditions was developed. This protocol was based on the intramuscular injection of filtered (0.22 μm) tissue homogenates prepared from naturally OsHV-1 infected spat collected on French coasts during mortality outbreaks in 2008. Results of the experimental trials showed that mortalities were induced after injection. Moreover, filtered tissue homogenates induced mortalities whereas the same tissue homogenates exposed to an ultraviolet (UV) treatment did not induce any mortality suggesting that oyster spat mortalities require the presence of a UV sensitive agent. Furthermore, analysis of injected oyster spat revealed the detection of high amounts of OsHV-1 DNA by real-time quantitative PCR. Finally, TEM analysis demonstrated the presence of herpes virus particles. The developed protocol allowed to maintain sources of infective virus which can be useful for the development of further studies concerning the transmission and the development of OsHV-1 infection.
2008 年和 2009 年，法国太平洋牡蛎（Crassostrea gigas）幼贝大量死亡。人们提出了不同的假说，包括环境因素、有毒藻类和/或病原体的影响。诊断检测表明，大多数样本中都检测到了疱疹病毒 1 型（OsHV-1），包括一种特定的基因型 OsHV-1μVar，特别是在濒死的牡蛎中检测到了病毒颗粒，电镜检查显示这些病毒颗粒类似于疱疹病毒。在这项研究中，开发了一种在实验室条件下重现 OsHV-1 感染的实验方案。该方案基于肌肉内注射从 2008 年法国沿海死亡率爆发期间收集的自然感染 OsHV-1 的幼贝的过滤（0.22 μm）组织匀浆。实验结果表明，注射后会引起死亡。此外，过滤的组织匀浆会引起死亡，而经过紫外线（UV）处理的相同组织匀浆则不会引起任何死亡，这表明牡蛎幼贝的死亡需要存在对 UV 敏感的物质。此外，对注射的牡蛎幼贝进行分析显示，实时定量 PCR 检测到了大量的 OsHV-1 DNA。最后，电镜分析证明了疱疹病毒颗粒的存在。该方案允许维持感染性病毒的来源，这对于进一步研究 OsHV-1 的传播和感染发展非常有用。
