Previous Article | Next Article ![]()
Journal of Bacteriology, October 2000, p. 5551-5555, Vol. 182, No. 19
Department of Physics, Chalmers University of
Technology and Göteborg University,1 and
Department of Cell and Molecular Biology-Microbiology,
Göteborg University,2 Göteborg,
Sweden
Received 15 March 2000/Accepted 6 July 2000
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, may occur. The usefulness of
the optical trapping methodology in elucidating the mechanisms involved
in stationary-phase-induced bacterial death and population
heterogeneity is discussed.
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Sorting Out Bacterial Viability with Optical
Tweezers
*
Corresponding author. Mailing address:
CMB-Microbiology, Göteborg University, Box 462, 405 30 Göteborg, Sweden. Phone: (46) 31 773 2582. Fax: (46) 31 773 2599. E-mail: thomas.nystrom{at}gmm.gu.se.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |