Megan Sousa L&S Sciences
Characterizing Single Cell Motility in Bacterial Biofilms
Research on bacterial antibiotic resistance evolution has primarily been carried out in liquid culture; however, many infections are in the form of biofilms. Biofilms are composed of bacteria embedded in a complex matrix that protects pathogenic bacteria making them highly virulent, much more difficult to treat in patients, and an important focus of medical research. One interesting characteristic of biofilm growth is that genetically-identical cells can differentiate into multiple cell types, such as motile cells, which can swim within the biofilm. It is unclear how much these swimming cells can disrupt the spatial organization within the biofilm and change the evolutionary outcome for antibiotic-resistant mutants that arise. I will be characterizing single cell motility in the model biofilm Bacillus subtilis. I will use fluorescence microscopy and genetics to quantify the lengthscale of passive motion due to diffusion and active movement due to swimming exhibited by single cells in the biofilm. Quantifying the movement of single cells will allow us to create better predictive models of evolutionary dynamics of antibiotic resistance in biofilms.