Berlin 2012 – scientific programme

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BP: Fachverband Biologische Physik

BP 18: Posters: Statistical Physics in Biological Systems

BP 18.5: Poster

Wednesday, March 28, 2012, 17:30–19:30, Poster A

Evolution of drug resistance in a spatially structured environment — •Bartlomiej Waclaw, Philip Greulich, and Rosalind Allen — School of Physics, University of Edinburgh

Evolution of drug-resistant cells is an increasingly important problem in our quest to combat diseases such as bacterial infections or cancer. Many methods have been proposed to circumvent this problem, ranging from switching the drug periodically on and off, using a combination of drugs, or alternating drugs belonging to different classes. However, the majority of these studies (experimental and theoretical) have been carried out for well-mixed populations with spatially uniform distribution of the drug. Here we theoretically analyse the effect of a non-uniform distribution of a drug (e.g. an antibiotic) on the emergence of resistance to it, in a spatially structured population of malignant cells. Motivated by recent experiments on bacteria, we propose a simple stochastic model in which pathogenic microbes replicate, mutate, die and migrate in a box in which the antibiotic concentration changes in space from sub-lethal to overkill levels. We assume that resistance occurs by a sequence of consecutive mutations. Depending on the resistance levels of intermediate mutants (the "pathway to resistance"), we show that heterogeneous drug distribution can either dramatically speed up or slow down the evolution of resistance compared to the case of uniform distribution. We also discuss practical implications of our results for various modes of disease treatment.