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Microrheology and Spatial Heterogeneity of Staphylococcus aureus Biofilms Modulated by Hydrodynamic Shear and Biofilm-Degrading Enzymes.
Langmuir ( IF 3.7 ) Pub Date : 2019-02-15 , DOI: 10.1021/acs.langmuir.8b04252
J W Hart , T A Waigh , J R Lu , I S Roberts 1
Langmuir ( IF 3.7 ) Pub Date : 2019-02-15 , DOI: 10.1021/acs.langmuir.8b04252
J W Hart , T A Waigh , J R Lu , I S Roberts 1
Affiliation
Particle tracking microrheology was used to investigate the viscoelasticity of Staphylococcus aureus biofilms grown in microfluidic cells at various flow rates and when subjected to biofilm-degrading enzymes. Biofilm viscoelasticity was found to harden as a function of shear rate but soften with increasing height away from the attachment surface in good agreement with previous bulk results. Ripley's K-function was used to quantify the spatial distribution of the bacteria within the biofilm. For all conditions, biofilms would cluster as a function of height during growth. The effects of proteinase K and DNase-1 on the viscoelasticity of biofilms were also investigated. Proteinase K caused an order of magnitude change in the compliances, softening the biofilms. However, DNase-1 was found to have no significant effects over the first 6 h of development, indicating that DNA is less important in biofilm maintenance during the initial stages of growth. Our results demonstrate that during the preliminary stages of Staphylococcus aureus biofilm development, column-like structures with a vertical gradient of viscoelasticity are established and modulated by the hydrodynamic shear caused by fluid flow in the surrounding environment. An understanding of these mechanical properties will provide more accurate insights for removal strategies of early-stage biofilms.
中文翻译:
水动力剪切和生物膜降解酶调节金黄色葡萄球菌生物膜的微流变学和空间异质性。
粒子追踪微流变学用于研究在微流体细胞中以不同流速生长并受到生物膜降解酶作用时金黄色葡萄球菌生物膜的粘弹性。发现生物膜粘弹性随着剪切速率的变化而变硬,但随着远离附着表面的高度的增加而变软,这与之前的体积结果非常一致。Ripley 的 K 函数用于量化生物膜内细菌的空间分布。在所有条件下,生物膜在生长过程中都会聚集成高度的函数。还研究了蛋白酶 K 和 DNase-1 对生物膜粘弹性的影响。蛋白酶 K 导致顺应性发生数量级的变化,软化生物膜。然而,DNase-1 在发育的前 6 小时内没有显着影响,表明 DNA 在生长初始阶段的生物膜维持中不太重要。我们的结果表明,在金黄色葡萄球菌生物膜发育的初始阶段,具有垂直粘弹性梯度的柱状结构被建立并受到周围环境中流体流动引起的流体动力剪切的调节。了解这些机械特性将为早期生物膜的去除策略提供更准确的见解。
更新日期:2019-02-01
中文翻译:
水动力剪切和生物膜降解酶调节金黄色葡萄球菌生物膜的微流变学和空间异质性。
粒子追踪微流变学用于研究在微流体细胞中以不同流速生长并受到生物膜降解酶作用时金黄色葡萄球菌生物膜的粘弹性。发现生物膜粘弹性随着剪切速率的变化而变硬,但随着远离附着表面的高度的增加而变软,这与之前的体积结果非常一致。Ripley 的 K 函数用于量化生物膜内细菌的空间分布。在所有条件下,生物膜在生长过程中都会聚集成高度的函数。还研究了蛋白酶 K 和 DNase-1 对生物膜粘弹性的影响。蛋白酶 K 导致顺应性发生数量级的变化,软化生物膜。然而,DNase-1 在发育的前 6 小时内没有显着影响,表明 DNA 在生长初始阶段的生物膜维持中不太重要。我们的结果表明,在金黄色葡萄球菌生物膜发育的初始阶段,具有垂直粘弹性梯度的柱状结构被建立并受到周围环境中流体流动引起的流体动力剪切的调节。了解这些机械特性将为早期生物膜的去除策略提供更准确的见解。