Cordero, M.; Thomsen, B. H.; Talliou, A.; Ehrmann, A. K.; Svenningsen, S. L.; Mitarai, N.; Jauffred, L.

The survival of bacterial communities depends on complex dynamics at molecular, cellular, and ecosystem levels. Understanding antibiotic resistance requires a broader community context, as emergent dynamics can lead to unexpected outcomes, such as the persistence of susceptible populations or community collapse. We capture these behaviors by integration of microscopy and mathematical modeling to understand how bacterial interactions and spatial organization shape bacteriostatic antibiotic resistance in a two-strain community. We show that local chloramphenicol detoxification and mechanical pushing shape bacterial coexistence and spatial organization, promoting the survival and growth of otherwise susceptible bacteria. Additionally, the timing of antibiotic administration critically determines the growth dynamics, co-existence, local diversity of susceptible and resistant bacteria, and overall community resistance. Together, these insights highlight how community-level interactions fundamentally reshape antibiotic responses and open new avenues to understand and control bacterial resilience.