Department of Animal Science, Jeonbuk National University, Jeonju-si, Jeollabuk-do, 54896, South Korea.
Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802-4400, USA.
Environ Microbiol. 2021 May;23(5):2335-2338. doi: 10.1111/1462-2920.15463. Epub 2021 Mar 24.
Most bacteria lead lives of quiet desperation, so they sleep. By sleeping, bacteria survive ubiquitous stress, such as antibiotics, and can resuscitate to reconstitute infections. As for other nearly universal and highly regulated processes such as biofilm formation, in persistence, a small population of cells have an elegantly-regulated pathway to become dormant. By inactivating their ribosomes, persister cells sleep through stress and resuscitate once (i) the stress is removed, (ii) nutrients are presented and (iii) ribosome content reaches a threshold. During stress, cells often become spheroid and die, becoming hollow, membrane-enclosed vessels. How cellular content is lost is unclear, but it is obvious that these 'cell shells' are dead; i.e., 'There's no there there'. Critically, due to their intact membranes, the shells appear with membrane-impenetrant stains as 'viable' particles. Unfortunately, the microbiology field of 'viable but non-culturable cells' (VBNCs), though important for demonstrating the existence of dormant bacteria as a result of myriad stress states, has often mistaken these non-viable shells as viable particles that mysteriously may be reborn, when an appropriate incantation is made. We argue here, based on experimental data, that if resuscitation occurs, it is the persister (always-viable) cell population that revives, rather than the cell husks, which are dead.
大多数细菌过着默默无闻的生活，因此它们会休眠。通过休眠，细菌可以在抗生素等无处不在的压力下存活，并复苏以重新感染。对于其他几乎普遍存在且高度调控的过程，如生物膜形成，在持久性中，一小部分细胞有一种优雅的调控途径使其休眠。通过使核糖体失活，持久细胞可以在压力下休眠，一旦（i）压力消除，（ii）营养物质存在，以及（iii）核糖体含量达到阈值，就可以复苏。在压力下，细胞通常会变成球形并死亡，变成空心的、膜包裹的容器。细胞内容物如何丢失尚不清楚，但显然这些“细胞壳”是死的；也就是说，“那里什么都没有”。至关重要的是，由于它们的完整膜，这些壳在膜不可渗透的染色剂下呈现出“存活”的颗粒。不幸的是，微生物学领域的“可存活但非可培养细胞”（VBNCs）虽然对于证明休眠细菌的存在是由于无数压力状态很重要，但经常将这些不可存活的壳误认为是可能神秘复活的存活颗粒，只要施加适当的咒语即可。在这里，我们根据实验数据提出，只要复苏发生，复苏的是持久（始终存活）的细胞群体，而不是死亡的细胞外壳。
