Monday, March 28, at 12:10 p.m. in CUE 419
Eva Top, Professor of Biology, University of Idaho
Dr. Top is Professor of Biology at the University of Idaho. She received her Masters and Ph.D. degrees from the Ghent University in Belgium. She is also the Director of the Bioinformatics and Computational Biology graduate program at the University of Idaho (BCB). Her research is currently focused on the ecology and evolution of multi-drug resistance (MDR) plasmids in bacteria. Since rapid spread of MDR to human pathogens threatens our fight against infectious diseases, novel therapies are needed that limit the spread of new resistance genes. However, the factors that determine successful transfer and persistence of MDR plasmids are still poorly understood. Her main research questions focus on the evolutionary mechanisms and dynamics of plasmid host range evolution, including the effects of biofilm growth on these processes. She is also interested in the diversity and evolutionary history of natural MDR plasmids, and studies the effects of spreading dairy manure on the abundance and diversity of MDR plasmids in soils.
Rapidly improving persistence of antibiotic resistance plasmids and the impact of biofilm growth
The World Health Organization has declared the emergence of antibiotic resistant pathogens to be a global threat to human health. Multi-drug resistance (MDR) plasmids play a key role in this health crisis because they can transfer multiple resistance genes to a range of bacteria in a single genetic event. To limit the spread of antibiotic resistance by plasmids, we need to gain insight into the mechanisms by which the persistence of plasmids can rapidly improve in new bacterial hosts, even in the absence of antibiotics. Initially unstable plasmids have shown improved persistence through evolution of the plasmid, the bacterial host, or both. I will first give an overview of the general evolutionary mechanisms that lead to better retention of MDR plasmids, and thus persistent antibiotic resistant bacteria. I will then demonstrate that the environment in which the bacteria grow affects the outcome of this evolutionary process. We hypothesize that the evolutionary mechanisms by which MDR plasmid persistence improves are different and more diverse when bacteria are grown in biofilms than in well-mixed liquid cultures. Our model organism used to test this hypothesis is the opportunistic pathogen Acinetobacter baumannii, well known for its ability to form biofilms and for causing increasingly prevalent hospital acquired infections.
