Plasmids are infectious agents abundant in bacteria. By imposing selective pressure and moving genes between bacteria, they generate diversity, shape the structure and function of microbial communities, and drive resistance to antibiotics. However, to understand these effects, we need a deeper understanding of the structure of plasmid communities, of which we know very little. In this talk, I will first show what the structure of a plasmid genetic similarity network (sampled from empirical data) can tell us about the potential transmission of antibiotic resistance. Then, using an agent-based model, I will demonstrate how the interplay between the structure of plasmid-microbe infection networks influences community dynamics, showcasing the emergent dynamics of these complex ecological systems.