MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Sète, France.
IHPE, Univ Montpellier, CNRS, Ifremer, UPVD, Montpellier, France.
Mar Environ Res. 2021 Mar;165:105251. doi: 10.1016/j.marenvres.2020.105251. Epub 2021 Jan 9.
Significant mortality of Crassostrea gigas juveniles is observed systematically every year worldwide. Pacific Oyster Mortality Syndrome (POMS) is caused by Ostreid Herpesvirus 1 (OsHV-1) infection leading to immune suppression, followed by bacteraemia caused by a consortium of opportunistic bacteria. Using an in-situ approach and pelagic chambers, our aim in this study was to identify pathogen dynamics in oyster flesh and in the water column during the course of a mortality episode in the Mediterranean Thau lagoon (France). OsHV-1 concentrations in oyster flesh increased before the first clinical symptoms of the disease appeared, reached maximum concentrations during the moribund phase and the mortality peak. The structure of the bacterial community associated with oyster flesh changed in favour of bacterial genera previously associated with oyster mortality including Vibrio, Arcobacter, Psychrobium, and Psychrilyobacter. During the oyster mortality episode, releases of OsHV-1 and opportunistic bacteria were observed, in succession, in the water surrounding the oyster lanterns. These releases may favour the spread of disease within oyster farms and potentially impact other marine species, thereby reducing marine biodiversity in shellfish farming areas.
每年全球范围内都会系统性地观察到巨牡蛎幼体的大量死亡。太平洋牡蛎死亡综合征（POMS）是由牡蛎疱疹病毒 1（OsHV-1）感染引起的，导致免疫抑制，随后由机会性细菌联合体引起菌血症。本研究采用原位方法和浮游生物室，旨在确定地中海托湖（法国）牡蛎死亡过程中牡蛎肉和水柱中的病原体动态。在疾病的第一个临床症状出现之前，牡蛎肉中的 OsHV-1 浓度增加，在濒死期和死亡率高峰期达到最大值。与牡蛎肉相关的细菌群落结构发生变化，有利于以前与牡蛎死亡相关的细菌属，包括弧菌、拟杆菌、嗜冷菌和Psychrilyobacter。在牡蛎死亡期间，相继观察到 OsHV-1 和机会性细菌从牡蛎灯笼周围的水中释放。这些释放可能有利于疾病在牡蛎养殖场内的传播，并可能影响其他海洋物种，从而降低贝类养殖区的海洋生物多样性。
