Abstract for: Simulating the spread of resistance to antibiotics

Antibiotic resistance is a major clinical and public health issue causing difficulties in treating infectious diseases and increased risk for complications that lead to fatal outcome. The epidemiology of resistance is a function of the innate characteristics of the bacteria, transmission rates and the consumption of antibiotics. While there are cases where prudent usage of antibiotics leads to decrease in resistant frequency, there are examples where reduction does not lead to reversibility. The dynamics of this complex relationship can be profitably explored by system dynamics simulations. In this paper a generic model describing the transmission of commensal bacteria within a community exposed to different levels of antibiotics is simulated and analytical expressions describing the conditions for reversibility are derived. It is shown that cutting back the volume of antibiotics is necessary but not sufficient to reduce resistance frequency. The biological cost for sustaining resistant traits (fitness cost) and the lateral transmission of genetic material plays a critical role.