State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen Universitygrid.12955.3a, Xiamen, China.
College of Ocean and Earth Sciences, Xiamen Universitygrid.12955.3a, Xiamen, China.
Microbiol Spectr. 2022 Aug 31;10(4):e0149922. doi: 10.1128/spectrum.01499-22. Epub 2022 Jul 11.
is an opportunistic marine bacterium that persists in the global ocean and has important ecological significance. However, current knowledge about the diversity and ecology of alterophages (phages that infect ) is lacking. Here, three similar phages infecting Alteromonas macleodii ATCC 27126 were isolated and physiologically characterized. Transmission electron microscopy revealed morphology, with an oblate icosahedral head and a long noncontractile tail. Notably, these members displayed a small burst size (15-19 plaque-forming units/cell) yet an extensively broad host spectrum when tested on 175 strains. Such unique infection kinetics are potentially associated with discrepancies in codon usage bias from the host tRNA inventory. Phylogenetic analysis indicated that the three phages are closely evolutionarily related; they clustered at the species level and represent a novel genus. Three auxiliary metabolic genes with roles in nucleotide metabolism and putative biofilm dispersal were found in these phage genomes, which revealed important biogeochemical significance of these alterophages in marine ecosystems. Our isolation and characterization of these novel phages expand the current understanding of alterophage diversity, evolution, and phage-host interactions. The marine bacterium is prevalent in the global ocean with crucial ecological significance; however, little is known about the diversity and evolution of its bacteriophages that profoundly affect the bacterial communities. Our study characterized a novel genus of three newly isolated phages that exhibited a distinct infection strategy of broad host spectrum and small burst size. This strategy is likely a consequence of the viral trade-off between virulence and lysis profiles during phage-host coevolution, and our work provides new insight into viral evolution and infection strategies.
是一种机会主义海洋细菌，存在于全球海洋中，具有重要的生态意义。然而，目前对（感染的噬菌体）alterophages 的多样性和生态学知之甚少。在这里，分离并生理特征分析了三种感染 Alteromonas macleodii ATCC 27126 的类似噬菌体。透射电子显微镜显示出形态，具有扁球体的二十面体头部和长的不可收缩的尾巴。值得注意的是，这些成员表现出小的爆发大小（15-19 个噬菌斑形成单位/细胞），但在测试 175 个菌株时具有广泛的宿主谱。这种独特的感染动力学可能与宿主 tRNA 库存中的密码子使用偏好差异有关。系统发育分析表明，这三种噬菌体密切相关，它们在种水平上聚类，代表一个新属。在这些噬菌体基因组中发现了三个辅助代谢基因，它们在核苷酸代谢和可能的生物膜分散中起作用，这揭示了这些海洋 alterophages 在海洋生态系统中的重要生物地球化学意义。我们对这些新型噬菌体的分离和鉴定扩展了对 alterophage 多样性、进化和噬菌体-宿主相互作用的现有认识。海洋细菌 在全球海洋中普遍存在，具有重要的生态意义；然而，对于其噬菌体的多样性和进化知之甚少，这些噬菌体对细菌群落有着深远的影响。我们的研究对三种新分离的 噬菌体进行了分类，这些噬菌体表现出明显的广谱宿主感染策略和小爆发大小。这种策略可能是噬菌体-宿主共同进化过程中病毒毒力和裂解谱之间权衡的结果，我们的工作为病毒进化和感染策略提供了新的见解。
