Stewart Philip S, Zhang Tianyu, Xu Ruifang, Pitts Betsey, Walters Marshall C, Roe Frank, Kikhney Judith, Moter Annette
Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.
Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA.
NPJ Biofilms Microbiomes. 2016 Jun 22;2:16012. doi: 10.1038/npjbiofilms.2016.12. eCollection 2016.
Reaction-diffusion models were applied to gain insight into the aspects of biofilm infection and persistence by comparing mathematical simulations with the experimental data from varied bacterial biofilms. These comparisons, including three systems and two clinical investigations of specimens examined , underscored the central importance of concentration gradients of metabolic substrates and the resulting physiological heterogeneity of the microorganisms. Relatively simple one-dimensional and two-dimensional (2D) models captured the: (1) experimentally determined distribution of specific growth rates measured in cells within sputum from cystic fibrosis patients; (2) pattern of relative growth rate within aggregates of streptococcal biofilm harboured in an endocarditis vegetation; (3) incomplete penetration of oxygen into a biofilm under conditions of exposure to ambient air and also pure oxygen; (4) localisation of anabolic activity around the periphery of cell clusters formed in a flow cell and attribution of this pattern to iron limitation; (5) very low specific growth rates, as small as 0.025 h, in the interior of cell clusters within a biofilm in a complex 2D domain of variable cell density.
通过将数学模拟与来自不同细菌生物膜的实验数据进行比较，应用反应扩散模型来深入了解生物膜感染和持续存在的各个方面。这些比较，包括三个系统以及对所检查标本的两项临床研究，强调了代谢底物浓度梯度以及由此产生的微生物生理异质性的核心重要性。相对简单的一维和二维（2D）模型捕捉到了：（1）在囊性纤维化患者痰液中细胞内测得的特定生长速率的实验确定分布；（2）心内膜炎赘生物中链球菌生物膜聚集体内相对生长速率的模式；（3）在暴露于环境空气以及纯氧条件下氧气向生物膜的不完全渗透；（4）在流动池中形成的细胞簇周边合成代谢活性的定位，并将这种模式归因于铁限制；（5）在具有可变细胞密度的复杂二维区域中的生物膜内细胞簇内部极低的特定生长速率，低至0.025 h⁻¹ 。
