Assessing the role of bacterial plasmid replication in a competition model of sensitive and resistant bacteria to antibiotics

Abstract

<abstract> Antibiotic resistance is one of the top 10 public health problems that most affects humanity. In recent decades, plasmid-mediated antibiotic resistance (PMAR) has increased. However, due to the lack of knowledge about the biology of plasmids, there are gaps in the role played by them within antibiotic resistance. In this sense, properties that agree with the biological phenomenon and have contributed to the understanding of PMAR have been discovered from mathematical modeling. In this work, we focus on the role that the plasmid replication rate plays in the elimination or spread of bacteria both sensitive and resistant to antibiotics. Qualitative analysis reveals the existence of a free-bacteria equilibrium point, a resistant equilibrium point, and two coexistence equilibrium points (high and low bacterial load). If each bacterium (sensitive or resistant) produces at most one new bacterium, the infection will be controlled or eliminated. If each bacterium (sensitive or resistant) produces more than one bacteria, several scenarios of bacterial progression are presented that depend on the plasmid replication rate. The results suggest that plasmid replication is essential for the outcome of bacterial infection at the local level. </abstract>