(481g) Quantifying the Biophysical Properties of Bacterial Cells and Cell Clusters Released from Biofilms after Matrix-Targeted Disruption

Bacterial cells and cell clusters released from biofilms after biofilm-matrix targeted disruption are found to have distinct clustering characteristics and release profiles. Bacterial biofilms are structured communities of cells embedded in self-produced matrix materials. Biofilms can be viewed as a biocolloidal composite material, where bacterial cells are analogous to colloidal particles and their self-produced matrix materials (polysaccharides, proteins, DNA) are analogous to a viscoelastic hydrogel. An emerging biofilm removal strategy is matrix-targeted biofilm disruption. While it is known that matrix-targeted disruption can disassemble biofilm structures and weaken biofilm mechanics, little is known about the biophysical properties of the cells and cell clusters released from biofilms after matrix-targeted disruption. Here we evaluate the cellular concentration, cluster size, and cluster morphology of bacteria and bacterial clusters released from biofilms after treatment with biofilm matrix disruption agents targeting matrix polysaccharides, matrix proteins, matrix DNA or the total matrix. Released bacteria and bacterial clusters are imaged using confocal laser scanning microscopy. Quantitative image analysis is performed to determine cell concentration, cluster size, and cluster morphology. We find that the majority of cells released from biofilms are released as individual cells or dimers. Total matrix solubilization and targeted disruption of matrix polysaccharides result in the highest concentrations of cells released from biofilms. Additionally, targeted-disruption of matrix polysaccharides and targeted-disruption of matrix DNA lead to the release of cell clusters with sizes greater than 5 μm in diameter. Targeted disruption of matrix proteins shows a released cell profile comparable to that of an untreated biofilm. We discuss the significance of these results to released cell survivability, biofilm resilience, and the design of biofilm removal and eradication strategies.