Department of Biological Sciences, Bethel University, St. Paul, Minnesota, USA.
Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, USA.
Mol Oral Microbiol. 2024 Dec;39(6):477-490. doi: 10.1111/omi.12481. Epub 2024 Aug 19.
Biofilms are subjected to many environmental pressures that can influence community structure and physiology. In the oral cavity, and many other environments, biofilms are exposed to forces generated by fluid flow; however, our understanding of how oral biofilms respond to these forces remains limited. In this study, we developed a linear rocker model of fluid flow to study the impact of shear forces on Streptococcus gordonii and dental plaque-derived multispecies biofilms. We observed that as shear forces increased, S. gordonii biofilm biomass decreased. Reduced biomass was largely independent of overall bacterial growth. Transcriptome analysis of S. gordonii biofilms exposed to moderate levels of shear stress uncovered numerous genes with differential expression under shear. We also evaluated an ex vivo plaque biofilm exposed to fluid shear forces. Like S. gordonii, the plaque biofilm displayed decreased biomass as shear forces increased. Examination of plaque community composition revealed decreased diversity and compositional changes in the plaque biofilm exposed to shear. These studies help to elucidate the impact of fluid shear on oral bacteria and may be extended to other bacterial biofilm systems.
生物膜会受到多种环境压力的影响，这些压力会影响群落结构和生理机能。在口腔和许多其他环境中，生物膜会受到流体流动产生的力的影响；然而，我们对于口腔生物膜如何应对这些力的理解仍然有限。在这项研究中，我们开发了一种线性摇床模型来研究剪切力对戈登链球菌和牙菌斑衍生的多物种生物膜的影响。我们观察到，随着剪切力的增加，戈登链球菌生物膜的生物量减少。生物量的减少在很大程度上与细菌的总体生长无关。对暴露于中等水平剪切应力下的戈登链球菌生物膜进行的转录组分析发现，在剪切下有许多基因的表达存在差异。我们还评估了一个体外牙菌斑生物膜暴露于流体剪切力的情况。与戈登链球菌一样，随着剪切力的增加，牙菌斑生物膜的生物量也减少了。对菌斑群落组成的检查显示，暴露于剪切力下的菌斑生物膜多样性降低，组成发生变化。这些研究有助于阐明流体剪切对口腔细菌的影响，并可能扩展到其他细菌生物膜系统。
