Sorting out bacterial viability with optical tweezers
Sorting out bacterial viability with optical tweezers
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DOI：
10.1128/jb.182.19.5551-5555.2000
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发表时间：
2000-10-01
影响因子：
3.2
通讯作者：
Nyström, T
中科院分区：
文献类型：
--
作者：
Ericsson, M;Hanstorp, D;Nyström, T
我们已经开发了一种方法，使用激光，光镊和直接显微镜分析的生殖潜力和膜的完整性，以评估单细胞活力在一个固定相大肠杆菌人口。它在这里表明，减少细胞的完整性，确定通过使用荧光核酸染色碘化丙啶，以及相关的细胞增殖潜力的减少在静止期期间研究。而且。发现表现出降低的完整性的相同细胞是在营养物添加后不能分裂的细胞。少量但显著数量的完整细胞（7，466个中的496个[6.6%]）未能复制。换句话说，我们没有发现在所研究的静止期存在大量完整但不可培养的细胞的证据，但很明显，在膜完整性丧失之前，生殖能力可能会丧失。此外，约1%的静止期细胞在添加营养物后只能分裂一次，在少数情况下，分裂产生的两个细胞中只有一个能够进行第二次分裂，这表明发生了局部细胞退化，仅由其中一个子细胞继承，即mag。光学捕获方法的有用性在阐明参与静止相诱导的细菌死亡和人口异质性的机制进行了讨论。
We have developed a method, using laser, optical tweezers and direct microscopic analysis of reproductive potential and membrane integrity, to assess single-cell viability in a stationary-phase Escherichia coli population. It is demonstrated here that a reduction in cell integrity, determined by using the fluorescent nucleic acid stain propidium iodide, correlated well with a reduction in cell proliferating potential during the stationary-phase period studied. Moreover. the same cells that exhibited reduced integrity were found to be the ones that failed to divide upon nutrient addition. A small but significant number of the intact cells (496 of 7,466 [6.6%]) failed to replicate. In other words, we did not find evidence for the existence of a large population of intact but nonculturable cells during the stationary-phase period studied but it is clear that reproductive ability can be lost prior to the loss of membrane integrity, In addition, about 1% of the stationary-phase cells were able to divide only once upon nutrient addition, and in a few cases, only one of the two cells produced by division was able to divide a second time, indicating that localized cell deterioration, inherited by only one of the daughters, mag occur. The usefulness of the optical trapping methodology in elucidating the mechanisms involved in stationary-phase-induced bacterial death and population heterogeneity is discussed.