Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland.
Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA.
Open Biol. 2021 Sep;11(9):210188. doi: 10.1098/rsob.210188. Epub 2021 Sep 15.
The canonical lytic-lysogenic binary has been challenged in recent years, as more evidence has emerged on alternative bacteriophage infection strategies. These infection modes are little studied, and yet they appear to be more abundant and ubiquitous in nature than previously recognized, and can play a significant role in the ecology and evolution of their bacterial hosts. In this review, we discuss the extent, causes and consequences of alternative phage lifestyles, and clarify conceptual and terminological confusion to facilitate research progress. We propose distinct definitions for the terms 'pseudolysogeny' and 'productive or non-productive chronic infection', and distinguish them from the carrier state life cycle, which describes a population-level phenomenon. Our review also finds that phages may change their infection modes in response to environmental conditions or the physiological state of the host cell. We outline known molecular mechanisms underlying the alternative phage-host interactions, including specific genetic pathways and their considerable biotechnological potential. Moreover, we discuss potential implications of the alternative phage lifestyles for microbial biology and ecosystem functioning, as well as applied topics such as phage therapy.
近年来，随着越来越多的证据表明噬菌体存在替代感染策略，经典的裂解-溶源二元性受到了挑战。这些感染模式尚未得到充分研究，但它们在自然界中似乎比以前认识到的更为丰富和普遍，并且可以在其细菌宿主的生态和进化中发挥重要作用。在这篇综述中，我们讨论了替代噬菌体生活方式的程度、原因和后果，并澄清了概念和术语上的混淆，以促进研究进展。我们为“拟溶源”和“有生产力或无生产力的慢性感染”这两个术语提出了明确的定义，并将它们与描述种群水平现象的载体状态生命周期区分开来。我们的综述还发现，噬菌体可能会根据环境条件或宿主细胞的生理状态改变其感染模式。我们概述了替代噬菌体-宿主相互作用的已知分子机制，包括特定的遗传途径及其相当大的生物技术潜力。此外，我们还讨论了替代噬菌体生活方式对微生物生物学和生态系统功能的潜在影响，以及噬菌体治疗等应用主题。
