Heterogeneity of single cell inactivation: Assessment of the individual cell time to death and implications in population behavior
Heterogeneity of single cell inactivation: Assessment of the individual cell time to death and implications in population behavior
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DOI：
10.1016/j.fm.2018.12.011
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发表时间：
2019-06-01
影响因子：
5.3
通讯作者：
Koutsoumanis, Konstantinos
中科院分区：
文献类型：
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作者：
Aspridou, Zafeiro;Balomenos, Athanasios;Koutsoumanis, Konstantinos
使用共聚焦扫描激光显微镜中细胞活力的适当染色的直接显微镜延时法，用于直接评估暴露于渗透压应力的小二维菌落中的Agona沙门氏菌个体细胞灭活。使用@Risk软件将单个细胞灭活时间拟合至各种连续分布。最佳拟合分布（LogLogistic）被进一步用于使用Monte Carlo模拟来预测各种初始水平的沙门氏菌种群的灭活。模拟结果表明，在灭活动力学的变化是可以忽略不计的浓度下降到100个细胞和群体行为可以用确定性模型来描述。然而，随着浓度降低至低于100个细胞，变异性显著增加，表明确定性一级动力学模型中使用的传统D值无效。在第二阶段，在较大的三维集落中监测单细胞行为。结果表明，菌落大小可以影响灭活模式。通过验证实验证实了菌落大小对微生物灭活的影响，验证实验表明，与由较大菌落组成的细胞组成的群体相比，由单细胞或小菌落组成的群体的灭活率更高。
A direct microscopic time-lapse method, using appropriate staining for cell viability in a confocal scanning laser microscope, was used for the direct assessment of Salmonella Agona individual cell inactivation in small two dimensional colonies exposed to osmotic stress. Individual cell inactivation times were fitted to a variety of continuous distributions using @Risk software. The best fitted distribution (LogLogistic) was further used to predict the inactivation of Salmonella populations of various initial levels using Monte Carlo simulation. The simulation results showed that the variability in inactivation kinetics is negligible for concentrations down to 100 cells and the population behavior can be described with a deterministic model. As the concentration decreases below 100 cells, however, the variability increases significantly indicating that the traditional D-value used in deterministic first order kinetic models is not valid. At a second stage, single cell behavior was monitored in larger three dimensional colonies. The results showed that colony size can affect the inactivation pattern. The effect of colony size on microbial inactivation was confirmed with validation experiments which showed a higher inactivation rate for populations consisting of single cells or small colonies compared to those consisting of cells organized in larger colonies.