Interdisciplinary Center for Aquaculture Research, University of Concepción, Concepción, Chile.
Laboratory of Biotechnology and Aquatic Genomics, Center of Biotechnology, University of Concepción, Concepción, Chile.
Sci Rep. 2020 Feb 19;10(1):2895. doi: 10.1038/s41598-020-59747-0.
Caligus rogercresseyi is a copepod ectoparasite with a high prevalence in salmon farms in Chile, causing severe welfare and economic concerns to the sector. Information on the parasite's underpinning mechanisms to support its life strategy is recently being investigated. Due to the critical role of microbiota, this study aimed to characterize the microbiota community associated with C. rogercresseyi from different regions with salmon aquaculture in Chile. Using third-generation sequencing with Nanopore technology (MinION) the full 16S rRNA gene from sea lice obtained from 8 areas distributed over the three main aquaculture regions were sequenced. Microbiota of the parasite is mainly comprised of members of phyla Proteobacteria and Bacteroidetes, and a core microbiota community with 147 taxonomical features was identified, and it was present in sea lice from the three regions. This community accounted for 19% of total identified taxa but more than 70% of the total taxonomical abundance, indicating a strong presence in the parasite. Several taxa with bioactive compound secretory capacity were identified, such as members of genus Pseudoalteromonas and Dokdonia, suggesting a possible role of the lice microbiota during the host infestation processes. Furthermore, the microbiota community was differentially associated with the salmon production, where several potential pathogens such as Vibrio, Tenacibaculum, and Aeromonas in Los Lagos, Aysén, and Magallanes region were identified. Notably, the Chilean salmon industry was initially established in the Los Lagos region but it's currently moving to the south, where different oceanographic conditions coexist with lice populations. The results originated by this study will serve as foundation to investigate putative role of sea lice as vectors for fish pathogens and also as reservoirs for antibiotic-resistant genes.
罗杰氏歪尾镖水蚤是一种桡足类外寄生虫，在智利的鲑鱼养殖场中广泛存在，给该行业的福利和经济带来了严重的问题。最近正在研究寄生虫支持其生活策略的基础机制信息。由于微生物组的重要作用，本研究旨在从智利三个主要水产养殖区的 8 个不同地区与鲑鱼养殖相关的 C. rogercresseyi 中，对其微生物群落进行特征描述。使用 Nanopore 技术（MinION）的第三代测序，对从分布在三个主要水产养殖区的 8 个地区获得的海虱的全长 16S rRNA 基因进行了测序。寄生虫的微生物组主要由变形菌门和拟杆菌门的成员组成，确定了一个由 147 个分类特征组成的核心微生物群落，且在来自三个地区的海虱中均存在。该群落占总鉴定分类群的 19%，但占总分类丰度的 70%以上，表明其在寄生虫中存在较强的丰度。鉴定出了一些具有生物活性化合物分泌能力的分类群，如假交替单胞菌属和 Dokdonia 属的成员，这表明海虱微生物组可能在宿主侵染过程中发挥作用。此外，微生物组与鲑鱼养殖存在差异相关性，在洛斯湖、阿耶森和麦哲伦地区鉴定出了一些潜在的病原体，如弧菌、Tenacibaculum 和气单胞菌。值得注意的是，智利鲑鱼产业最初是在洛斯湖地区建立的，但目前正在向南方转移，那里的海洋条件与海虱种群共存。本研究的结果将为调查海虱作为鱼类病原体载体以及抗生素耐药基因的储库的潜在作用提供基础。
