Email updates

Keep up to date with the latest news and content from BMC Evolutionary Biology and BioMed Central.

Open Access Highly Accessed Research article

The evolution of plasmid-carried antibiotic resistance

Fabian Svara1 and Daniel J Rankin12*

Author Affiliations

1 Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Building Y27, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

2 Swiss Institute of Bioinformatics, Quartier Sorge, Bâtiment Génopode, CH-1015 Lausanne, Switzerland

For all author emails, please log on.

BMC Evolutionary Biology 2011, 11:130  doi:10.1186/1471-2148-11-130

Published: 19 May 2011



Antibiotic resistance represents a significant public health problem. When resistance genes are mobile, being carried on plasmids or phages, their spread can be greatly accelerated. Plasmids in particular have been implicated in the spread of antibiotic resistance genes. However, the selective pressures which favour plasmid-carried resistance genes have not been fully established. Here we address this issue with mathematical models of plasmid dynamics in response to different antibiotic treatment regimes.


We show that transmission of plasmids is a key factor influencing plasmid-borne antibiotic resistance, but the dosage and interval between treatments is also important. Our results also hold when plasmids carrying the resistance gene are in competition with other plasmids that do not carry the resistance gene. By altering the interval between antibiotic treatments, and the dosage of antibiotic, we show that different treatment regimes can select for either plasmid-carried, or chromosome-carried, resistance.


Our research addresses the effect of environmental variation on the evolution of plasmid-carried antibiotic resistance.

plasmid; resistance; antibiotic; horizontal gene transfer; mobile elements