Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante 03690, Spain.
Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States.
ISME J. 2024 Jan 8;18(1). doi: 10.1093/ismejo/wrae017.
The increasing trend in sea surface temperature promotes the spread of Vibrio species, which are known to cause diseases in a wide range of marine organisms. Among these pathogens, Vibrio mediterranei has emerged as a significant threat, leading to bleaching in the coral species Oculina patagonica. Bacteriophages, or phages, are viruses that infect bacteria, thereby regulating microbial communities and playing a crucial role in the coral's defense against pathogens. However, our understanding of phages that infect V. mediterranei is limited. In this study, we identified two phage species capable of infecting V. mediterranei by utilizing a combination of cultivation and metagenomic approaches. These phages are low-abundance specialists within the coral mucus layer that exhibit rapid proliferation in the presence of their hosts, suggesting a potential role in coral defense. Additionally, one of these phages possesses a conserved domain of a leucine-rich repeat protein, similar to those harbored in the coral genome, that plays a key role in pathogen recognition, hinting at potential coral-phage coevolution. Furthermore, our research suggests that lytic Vibrio infections could trigger prophage induction, which may disseminate genetic elements, including virulence factors, in the coral mucus layer. Overall, our findings underscore the importance of historical coral-phage interactions as a form of coral immunity against invasive Vibrio pathogens.
海表温度的上升趋势促进了弧菌属物种的传播，这些物种已知会导致广泛的海洋生物患病。在这些病原体中，地中海弧菌已成为一个重大威胁，导致 Oculina patagonica 珊瑚白化。噬菌体，或 phages，是感染细菌的病毒，从而调节微生物群落，并在珊瑚抵御病原体方面发挥关键作用。然而，我们对感染地中海弧菌的噬菌体的了解有限。在这项研究中，我们利用培养和宏基因组学方法相结合，鉴定出了两种能够感染地中海弧菌的噬菌体。这些噬菌体是珊瑚黏液层中的低丰度专性噬菌体，在宿主存在的情况下迅速增殖，表明它们在珊瑚防御中可能发挥作用。此外，其中一种噬菌体具有富含亮氨酸重复蛋白的保守结构域，类似于珊瑚基因组中携带的那些，在病原体识别中发挥关键作用，暗示着潜在的珊瑚-噬菌体协同进化。此外，我们的研究表明，裂解性弧菌感染可能会引发前噬菌体的诱导，从而在珊瑚黏液层中传播遗传物质，包括毒力因子。总的来说，我们的研究结果强调了历史上珊瑚-噬菌体相互作用作为珊瑚抵御入侵性弧菌病原体的一种免疫形式的重要性。
