Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, China.
Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.
Appl Environ Microbiol. 2023 Jul 26;89(7):e0054323. doi: 10.1128/aem.00543-23. Epub 2023 Jun 14.
Coral reefs are among the most biodiverse ecosystems, providing habitats for various organisms. Studies on coral bleaching have been increasing recently, but little is known about the distribution and community assembly of coral pathogenic bacteria (e.g., several species). We elucidated the distribution pattern and interaction relationships of total bacteria and spp. in sediments from the Xisha Islands, which are characterized by their high coverage and diversity of coral resources. spp. showed significantly higher relative abundance values in the Xisha Islands (1.00 × 10 copies/g) than in other areas (approximately 1 × 10 to 9.04 × 10 copies/g), indicating that the coral bleaching event of 2020 may have promoted the bloom of vibrios. A spatial shift in community composition was observed between the northern (Photobacterium rosenbergii and Vibrio ponticus) and southern (Vibrio ishigakensis and Vibrio natriegens) sites, accompanied by a clear distance-decay pattern. The spatial distance and coral species (e.g., and ) had much greater correlations with the community than did environmental factors. However, complex mechanisms may exist in the community assembly of spp. due to the large proportion of unexplained variation. Stochastic processes may play an important role, as shown by the neutral model. Vibrio harveyi had the highest relative abundance (77.56%) and niche breadth, compared to other species, and it was negatively correlated with Acroporidae, likely reflecting its strong competitive ability and adverse effects on specific corals. Our study provides insights into the bloom and underlying assembly mechanisms of sedimentary vibrios in the Xisha Islands, thereby contributing to identify the potential indicator of coral bleaching and provide inspiration for the environmental management of coral reef areas. Coral reefs exert important roles in maintaining the sustainability of marine ecosystems but decline worldwide due to various drivers, especially pathogenic microorganisms. Here, we investigated the distribution pattern and interactions of total bacteria and spp. in the sediments from Xisha Islands during the coral bleaching event of 2020. Our results showed that the abundances of (1.00 × 10 copies/g) were high across the whole sites, indicating the bloom of sedimentary spp. Coral pathogenic species were abundant in the sediments, likely reflecting adverse effects on several kinds of corals. The compositions of the spp. were separated by geographical location, which was mainly attributable to the spatial distance and coral species. Overall, this work contributes by providing evidence for the outbreak of coral pathogenic vibrios. The pathogenic mechanism of the dominant species (especially V. harveyi) should be comprehensively considered by laboratory infection experiments in the future.
珊瑚礁是生物多样性最丰富的生态系统之一，为各种生物提供了栖息地。最近对珊瑚白化的研究一直在增加，但对珊瑚致病性细菌（例如几种）的分布和群落组装知之甚少。我们阐明了西沙群岛沉积物中总细菌和 spp 的分布模式和相互关系。这些岛屿的珊瑚资源覆盖率和多样性都很高。 spp. 的相对丰度值明显高于其他地区（约 1×10 到 9.04×10 拷贝/g），表明 2020 年的珊瑚白化事件可能促进了弧菌的爆发。在北部（发光杆菌和 Ponticus 弧菌）和南部（石垣弧菌和奈氏弧菌）站点之间观察到群落组成的空间转移，伴随着明显的距离衰减模式。空间距离和珊瑚物种（如 和 ）与 群落的相关性远大于环境因素。然而，由于未解释的变异比例较大， spp. 的群落组装可能存在复杂的机制。中性模型表明，随机过程可能发挥重要作用。与其他物种相比，哈维弧菌具有最高的相对丰度（77.56%）和生态位宽度，与 Acroporidae 呈负相关，可能反映了其较强的竞争力和对特定珊瑚的不利影响。我们的研究提供了对西沙群岛沉积物中弧菌爆发和潜在组装机制的深入了解，从而有助于确定珊瑚白化的潜在指标，并为珊瑚礁地区的环境管理提供启示。
珊瑚礁在维持海洋生态系统的可持续性方面发挥着重要作用，但由于各种驱动因素，尤其是致病微生物的影响，全球范围内的珊瑚礁都在减少。在这里，我们调查了 2020 年珊瑚白化期间西沙群岛沉积物中总细菌和 spp. 的分布模式和相互作用。我们的结果表明，整个地点的 spp.（1.00×10 拷贝/g）丰度都很高，表明沉积物中存在弧菌的爆发。珊瑚致病性 物种在沉积物中丰富，可能反映了对几种珊瑚的不利影响。 spp. 的组成由地理位置分离，主要归因于空间距离和珊瑚物种。总的来说，这项工作提供了珊瑚致病性弧菌爆发的证据。未来应通过实验室感染实验综合考虑优势种（特别是 V. harveyi）的致病机制。
