Mathematical modeling of plasmid-mediated antibiotic resistance dissemination in dual cell populations

Antibiotic resistance presents a critical challenge to global health, primarily driven by the dissemination of plasmid-borne resistance genes. This study develops a mathematical model to investigate how plasmid dynamics influence the evolution of bacterial resistance under antibiotic exposure. The model integrates a saturable plasmid transfer mechanism, reflecting the biological reality that horizontal gene transfer efficiency plateaus as recipient populations reach a density limit. Under constant antibiotic conditions, we find that antibiotic concentration is a primary determinant in suppressing pathogenic bacterial populations. In scenarios involving antibiotic degradation, simulations reveal that higher degradation rates and increased plasmid transfer rates accelerate the development of resistance. Conversely, raising the fitness cost of plasmid maintenance or enhancing plasmid segregation can effectively slow the emergence of resistance. These results underscore the value of strategically adjusting these parameters to improve treatment outcomes and limit the evolution of resistant bacteria.