Quantifying the Effect of Space on Antibiotic Resistance Evolution.

Induni Uresha Dias Kariyawasam Majuwana Gamage

Clarkson Univeristy

"Quantifying the Effect of Space on Antibiotic Resistance Evolution."

Antibiotics, which can be defined as substances that work against bacteria, are one of the most useful agents used in healthcare. As a result, they serve to treat and prevent many bacterial infections. However, due to the emergence of antibiotic resistance, where bacteria develop a mechanism to defend themselves against antibiotics, managing infections has become increasingly challenging. Antibiotic resistance in bacteria arises through genetic mutations or horizontal gene transfer. Spatial heterogeneity in antibiotic concentration has a potential to affect this bacterial evolution. For example, compared to a well mixed population, in a highly structured population, increased phenotypic and genotypic diversity, as well as slower adaptation, is expected. Here, we are studying the bacterial evolution under the stochastic processes of division, which is influenced by the availability of food sources in the culture, as well as by mutations and migration. As division reaction is time dependent, this chemical system is non-homogeneous and non-stationary. In this scenario, continuous time Markov processes can not be applied as chemical reactions are non-homogeneous and non-stationary. In this study, an expression was formulated to determine the time until the next reaction occurs, given the current state of the system, by considering the combined effects of division, migration, and mutation.

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