Abstract
Bacteriophages are viruses that attack and can completely eradicate susceptible populations of bacteria. Consequently, the bacteria-bacteriophage interaction is used as a model system for evolution where the phages act as a strong selective pressure. Increases to computational power over the past three decades have allowed us to go beyond simple population based models into complex individual-based models. However, modeling the biofilm-phage system with individual-based frameworks can cause unmanageable computational load because of the potential for explosive growth of the bacteriophage population. To solve this problem I have developed a biofilm hybrid cellular automaton and individual-based simulation framework that replicates key biofilm behaviors of growth and phage interaction. Using this framework, I first explored the impact of spatial structure on the steady states of susceptible bacteria-bacteriophages interaction. Next, I examined competition between resistant and susceptible strains of bacteria under the selective phage pressure. Finally, I studied the role of biofilm matrix production in the interplay of spatial competition and phage resistance. These in silico results play an important role in informing in vitro verification by narrowing the range of possible parameters to a level that is experimentally feasible, allowing for theoretically guided empirical studies about evolution.