Wendling Carolin C, Batista Frederico M, Wegner K Mathias
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Wadden Sea Station Sylt, Coastal Ecology, List, Schleswig-Holstein, Germany.
Instituto Português do Mar e da Atmosfera, Estação de Moluscicultura de Tavira, Olhão, Portugal.
PLoS One. 2014 Apr 11;9(4):e94256. doi: 10.1371/journal.pone.0094256. eCollection 2014.
Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods.
弧菌属细菌存在于从自由生活到共生生命形式的连续统一体中，包括机会致病菌和病原体，它们可导致严重疾病，例如太平洋牡蛎（长牡蛎）的夏季死亡事件。虽然大多数研究集中在死亡暴发期间从濒死牡蛎中分离出的弧菌，但对健康牡蛎中弧菌群落的调查却很少。因此，我们对从健康太平洋牡蛎中分离出的弧菌群落的持久性、多样性、季节动态和致病性进行了表征。在一项 reciprocal transplant 实验中，我们在野外原位孵化的六个月期间，反复从成年太平洋牡蛎中采集血淋巴，以区分种群效应和特定地点效应。我们基于多位点序列分型对总共70株弧菌菌株的毒力表型和基因组多样性进行了表征。基于对照感染实验，我们可以表明，具有定殖于健康成年牡蛎能力的菌株也有可能在幼虫上诱导高死亡率。弧菌的多样性和丰度随时间显著变化，在产卵季节期间和之后达到最高值。来自移植牡蛎和固定牡蛎的弧菌群落随时间趋同，这表明群落不是种群特异性的，而是从周围环境中聚集形成群落，其中一些群落可以持续较长时间。
