Abstracts (first author)
Modelling antibiotic resistance and plasmids
The spread of antibiotic resistance in bacteria is a major public health problem, threatening our ability to treat bacterial infections successfully.
Plasmids, extra-chromosomal pieces of DNA capable of horizontal transfer, are often implicated in the process of resistance acquisition, and potentially allow for the transfer of resistance genes between species and between genera. Some plasmids carry multiple resistance genes, simultaneously counteracting several antibiotics, and in extreme cases acquisition of a plasmid by a pathogen can confer resistance to virtually all antibiotics at a single stroke. The conditions favouring resistance genes to be located on plasmids rather than on chromosomes are therefore potentially of great importance.
Mathematical models are an excellent technique for investigating this topic, because they allow for simultaneous consideration of selection at three levels: genes, plasmids, and bacteria. We use models to consider whether plasmids are a favourable location for antibiotic resistance genes, and how spatially- or temporally-varying selection regimes can affect this. Answers to these questions provide a more complete understanding of the processes underlying the evolution of antibiotic resistance genes on plasmids, and could consequently be of great value in preventing the spread of resistance.