Dr. Eva Top

…Dr. Eva Top

I am currently a Professor in the Department of Biological Sciences at the University of Idaho. I teach upper level undergraduate and graduate level courses, see courses. I have a research group that currently consists of three postdoctoral scientists, one graduate student, one technician, and three undergraduate students. I am an editor for the journals Plasmid and FEMS Microbiology Ecology, and serve on the editorial board of Applied and Environmental Microbiology

I obtained both my degree in Bio-engineering (equivalent to a Master's degree in the U.S.) and my Ph.D. degree in Agricultural Sciences at Ghent University in Belgium, with Prof. Dr. ir. Willy Verstraete as my major professor. Except for a 17-month postdoctoral fellowship at the Center for Microbial Ecology at Michigan State University, and short visits in other labs, all my research up to mid-2001 was done at the Laboratory of Microbial Ecology and Technology at Ghent University, Belgium. In 1996 I obtained a permanent ‘Research Leader’ position from the Flemish Fund for Scientific Research at Ghent University. In 1997, I was appointed at Ghent University as part-time Assistant Professor, and eventually obtained a full-time permanent position there as Assistant Professor in 2000. After a two-year leave of absence from Ghent University (during which time I was a Research Associate Professor at the University of Idaho) I resigned my position at Ghent University in 2003.

At Ghent University I taught Molecular Microbial Ecology, and gave many ad hoc lectures in microbial ecology and environmental microbiology courses. My research program there was focused on:

  1. Understanding the diversity and horizontal spread of bacterial plasmids in soils and wastewater treatment systems, with an emphasis on using plasmids as genetic tools in bioremediation applications, such as biodegradation of recalcitrant chlorinated organic compounds; and,
  2. Use of molecular ecology methods to characterize the structure and dynamics of microbial communities in soils and water, and how these communities were affected by human activities such as agricultural practices.

Since I moved to the University of Idaho in 2001, my research focus has changed significantly, with a much stronger emphasis on basic questions regarding the ecology and evolution of bacterial mobile genetic elements, in particular plasmids that transfer to and replicate in a broad range of hosts. These plasmids play an important role in the rapid adaptation of their hosts to changing environments. A good example is the current epidemic of antibiotic resistance in human pathogens, which is in part due to the spread of drug resistance plasmids.

One research project is part of an NIH-funded COBRE grant that established the Center for Research on Processes in Evolution. The objective of this research is to discern patterns of plasmid evolution in bacteria through experimental evolution studies. The main goals of the project are: i) to assess the tempo and mechanisms of adaptive plasmid evolution in a single host and during frequent horizontal transmission among phylogenetically distinct hosts; and ii) to determine the molecular basis for the observed phenotypic changes that occur during such experimental plasmid evolution. Some of these studies are done in collaboration with Dr. Paul Joyce and Dr. Zaid Abdo, from the Department of Mathematics and Statistics.

A second project aims at enhancing our understanding of the diversity and evolutionary history of the extant pool of broad-host-range (BHR) plasmids. This is done by retrospective analysis of the complete genomes of 100 BHR plasmids. The DNA sequencing service is provided by Department of Energy (DOE) Joint Genome Institute (JGI), and the National Science Foundation provides funding to analyze and compare these genomes. Co-investigators in this project are Drs. Celeste Brown, Larry Forney, John Sullivan, as well as professors Frank Cronk and Jill Dacey from the Department of Art & Design.

The third project aims at developing mathematical models to predict the spatial dynamics of plasmid transfer and persistence, and is in collaboration with Dr. Steve Krone, from the Department of Mathematics and Statistics and funded by the National Institutes of Health. This research, unlike most previous studies, takes into account the fact that most bacteria in natural and clinical settings form biofilms attached to surfaces such as medical implants and the walls of intestines. It is by now fairly well established that spatial structure like in these bacterial biofilms can have profound effects on the ecological and evolutionary dynamics of populations. Therefore the long-term goal of this study is to understand the population biology of self-transmissible antibiotic resistance plasmids in spatially structured microbial communities: How does the spatial structure affect the ecological and evolutionary dynamics of plasmid-bacteria interactions?