Department of Biology, Program in Biotechnology and Biomedical Engineering, University of Massachusetts Dartmouth, North Dartmouth, MA, USA.
Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
ISME J. 2018 Feb;12(2):531-543. doi: 10.1038/ismej.2017.190. Epub 2017 Nov 10.
Many bacteria are adapted for attaching to surfaces and for building complex communities, termed biofilms. The biofilm mode of life is predominant in bacterial ecology. So too is the exposure of bacteria to ubiquitous viral pathogens, termed bacteriophages. Although biofilm-phage encounters are likely to be common in nature, little is known about how phages might interact with biofilm-dwelling bacteria. It is also unclear how the ecological dynamics of phages and their hosts depend on the biological and physical properties of the biofilm environment. To make headway in this area, we develop a biofilm simulation framework that captures key mechanistic features of biofilm growth and phage infection. Using these simulations, we find that the equilibrium state of interaction between biofilms and phages is governed largely by nutrient availability to biofilms, infection likelihood per host encounter and the ability of phages to diffuse through biofilm populations. Interactions between the biofilm matrix and phage particles are thus likely to be of fundamental importance, controlling the extent to which bacteria and phages can coexist in natural contexts. Our results open avenues to new questions of host-parasite coevolution and horizontal gene transfer in spatially structured biofilm contexts.
许多细菌适应于附着在表面并构建复杂的群落，称为生物膜。生物膜的生活方式在细菌生态学中占主导地位。同样，细菌也会暴露于无处不在的病毒病原体中，这些病毒被称为噬菌体。尽管生物膜-噬菌体的接触在自然界中可能很常见，但人们对噬菌体如何与生物膜中栖息的细菌相互作用知之甚少。噬菌体及其宿主的生态动态如何依赖于生物膜环境的生物学和物理特性也不清楚。为了在这一领域取得进展，我们开发了一个生物膜模拟框架，该框架捕捉了生物膜生长和噬菌体感染的关键机制特征。使用这些模拟，我们发现生物膜和噬菌体之间相互作用的平衡状态主要由生物膜的营养可用性、每个宿主遭遇的感染可能性以及噬菌体在生物膜群体中扩散的能力来控制。因此，生物膜基质和噬菌体颗粒之间的相互作用可能具有根本重要性，控制着细菌和噬菌体在自然环境中共同存在的程度。我们的研究结果为在空间结构的生物膜环境中宿主-寄生虫协同进化和水平基因转移的新问题开辟了途径。
