Microfluidic chemostat with deformable membranes: intracellular biofilm-like structure model

Summary form only given. Escherichia coli survive in the hostile environment of host organ and cause rigorous infections. They generally form high-density colony and sustain high resistance to drug treatment as well as immune systems. Elucidating the exact mechanisms of Escherichia coli infections have been intriguing question in the field of pathogenic microbiology. Recently, we developed a new microfluidic chemostat device for bacterial study overcoming the limitations of the conventional experimental tools. The architecture of the microfluidic chemostat is notably similar to bacterial biofilms, where cells grow in high-density, with channels for supplying nutrients and removing wastes. The size of the microfluidic chemostat is also similar to that of biofilms found in host organ infections. Specifically, the microfluidic chemostat with deformable membranes developed in this study is designed to have a very thin PDMS layer between two layers mimicking the host cell membrane, which helps to simulate the intracellular biofilm-like structure formation in terms of confined boundary and chemical composition. It also makes it possible to monitor individual cell´s behavior and gene expression of interest combined with fluorescence protein technique. Using this device, we observed considerable pressure up to 2.8 psi generated by cells expanding to extremely high density, which may explain the burst of host cell membrane occurred during uropathogenic bacteria infection. We also characterized the spatial and temporal distribution of stress response to correlate the mechanical stress to biological stress. Combining these findings with other information on biofilm formation and bacterial cell-cell communication will ultimately provide us with a better understanding of bacterial infection and potentially lead to new and improved treatment protocols