Final Activity Report Summary - RAMADA (Rapid microbial adapation via horizontal gene transfer: environmental management opportunities and public health concerns)
In this project, we created a European Research team that conducted leading-edge interdisciplinary research bridging molecular ecology and quantitative sciences applied to the topic of microbial adaptation via horizontal gene transfer (HGT) within an environmental and public health context. We built a multi-disciplinary, trans-national and gender-balanced team consisting - on average - of two early stage (ESR, < 4 years) and 2 experienced (ER< 4 to 10 years) researchers around a team leader full-time committed to the project (MER). In total, 4 ER (1 female, 3 males) and 6 ESR (3 male, 3 female) were connected to the project, covering the following countries: DK (2), FR (3), GE (1), IS (1), ESP (2), USA (1). In addition, we hosted visiting ESR on the project from USA (1) and FR (2).
The project was ambitious, as it aimed to give the MER the opportunity to launch a new line of research - observation and modelling of microbial interactions at the single-cell level. We were able to attain these goals. A new, user friendly, computational platform, called iDynoMiCS, has been developed, and has already been disseminated beyond the team and close collaborators via two international PhD courses. With this software platform, detailed simulations of cell-cell interactions in structured (biofilm) communities can be performed, via an individual based modelling approach. It has been modified to include the details of conjugal plasmid transfer, and results have indicated the potential limitation to plasmid invasion in biofilms. Experimentally, we have developed tools to observe cell-to-cell plasmid transfer at the individual cell level, and in real-time, using Pseudomonas putida, P. aeruginosa, and P. fluorescens as model organisms. These tools relied on complementary fluorescent bioreporter marker and 3-D microscopy.
We have quantified the dependency of transfer on cell length, cell division, and intercellular distance. We have experimentally confirmed temporary depression of plasmid transfer, and have demonstrated that invasion in a new cell type is contingent on growth. We have furthermore, and for the first time, discovered that plasmid carriage can stimulate biofilm development, which is also associated with a higher amount of exocellular DNA. The experimental demonstrations are adequately represented by the model.
In sum, we have successfully completed the project in terms of personnel training, scientific objectives attainment, and establishing the MER as a recognised researcher in the field on the EU level.
The project was ambitious, as it aimed to give the MER the opportunity to launch a new line of research - observation and modelling of microbial interactions at the single-cell level. We were able to attain these goals. A new, user friendly, computational platform, called iDynoMiCS, has been developed, and has already been disseminated beyond the team and close collaborators via two international PhD courses. With this software platform, detailed simulations of cell-cell interactions in structured (biofilm) communities can be performed, via an individual based modelling approach. It has been modified to include the details of conjugal plasmid transfer, and results have indicated the potential limitation to plasmid invasion in biofilms. Experimentally, we have developed tools to observe cell-to-cell plasmid transfer at the individual cell level, and in real-time, using Pseudomonas putida, P. aeruginosa, and P. fluorescens as model organisms. These tools relied on complementary fluorescent bioreporter marker and 3-D microscopy.
We have quantified the dependency of transfer on cell length, cell division, and intercellular distance. We have experimentally confirmed temporary depression of plasmid transfer, and have demonstrated that invasion in a new cell type is contingent on growth. We have furthermore, and for the first time, discovered that plasmid carriage can stimulate biofilm development, which is also associated with a higher amount of exocellular DNA. The experimental demonstrations are adequately represented by the model.
In sum, we have successfully completed the project in terms of personnel training, scientific objectives attainment, and establishing the MER as a recognised researcher in the field on the EU level.