Isolation and identification of Vibrio mediterranei 117-T6 as a pathogen associated with yellow spot disease of Pyropia (Bangiales, Rhodophyta)
Isolation and identification of Vibrio mediterranei 117-T6 as a pathogen associated with yellow spot disease of Pyropia (Bangiales, Rhodophyta)
复制标题
地中海弧菌 117-T6 与红藻门黄斑病相关病原菌的分离和鉴定
DOI：
10.1016/j.aquaculture.2020.735372
复制
发表时间：
2020-09-15
期刊：
影响因子：
4.5
通讯作者：
Chen, Haimin
中科院分区：
文献类型：
--
作者：
Yang, Rui;Liu, Qiqin;Chen, Haimin
焦藻是东北亚地区重要的养殖海藻。黄斑病（YSD）常见于褐皮虫螺孢子培养中，造成巨大的经济损失。在本研究中，分离的菌株117-T6根据Koch假设被鉴定为焦皮虫YSD的致病菌。根据其形态学、生理生化特征及管家基因序列的多位点分析，将该革兰氏阴性菌命名为地中海弧菌117-T6。地中海V. 117-T6，包括其细胞内和细胞外提取物，在12天内引起自由生活的螺螺（FLC）和壳源性螺螺（SBC）表现出YSD症状，表明该细菌可能通过分泌某些化合物来攻击热螺旋体，这些化合物可以被运输到藻类细胞中，破坏其结构并导致死亡。在感染过程中，观察到四个阶段。1)前期：藻类周围聚集了大量致病菌。当时的螺螺处于健康状态。2)早期：火虫细胞器边缘模糊，线粒体和叶绿体变得蓬松和解体，自噬体出现。3)中期：藻类细胞结构和内容物不断丢失和降解，细胞壁变薄。4)后期：螺壳完全漂白，随着细胞壁逐渐解体，细菌接管了焦皮菌的残骸。最后，整个藻细胞消失，这可能是导致壳白化的原因。我们的研究结果表明，地中海弧菌117-T6引起的YSD是一种由细菌分泌引起的严重的藻类崩解病，发病时间短，症状严重。
Pyropia is an important cultivated seaweed in Northeast Asia. Yellow spot disease (YSD) commonly occurs in conchocelis sporeling cultures of Pyropia and causes huge economic losses. In this study, the isolated strain 117-T6 was identified as a pathogenic bacterium of YSD in Pyropia by Koch's postulates. Based on the morphological, physiological, and biochemical characteristics and multi-locus analysis of house-keeping gene sequences, this gram-negative bacterium was named as Vibrio mediterranei 117-T6. V. mediterranei 117-T6, including its intracellular and the extracellular extracts, caused both free-living conchocelis (FLC) and shell-borne conchocelis (SBC) to exhibit YSD symptoms within 12 days, indicating that the bacteria might attack Pyropia by secreting certain compounds that can be transported into algal cells, breaking down their structure and leading to death. During the infection, four stages were observed. 1) Prophase: a large number of pathogenic bacteria gathered around the algae. The conchocelis was in healthy condition at that time. 2) Early stage: organelle edges of Pyropia were blurred, mitochondria and chloroplasts became fluffy and unraveled, autophagosomes appeared. 3) Middle stage: cellular structures and contents of the algae kept being lost and degraded, cell walls became thin. 4) Late stage: the conchocelis bleached completely, and as the cell wall disintegrated gradually, the bacteria took over the remains of Pyropia. Finally, the whole algal cell disappeared, which may be the reason for shell bleaching. Our results show that YSD caused by V. mediterranei 117-T6 is a severe disease of algal disintegration caused by bacterial secretion, with a short onset and severe symptoms.