Probing antibiotic residues and resistance transfer in aquatic environments

The project aims to study bacteria, antibiotic resistance genes (ARGs) and antibiotic residues in groundwater, surface water, wastewater, marine water environments in the North Sea and the Atlantic including ports, and aquaculture facilities. Samples will be collected from sites with high and low suspected loads of antibiotic residues. Culture-based and sequencing-based methods will be used to identify ARGs. Transfer of ARG-containing plasmids will be analyzed using indicator bacteria Escherichia coli, Vibrio spp., and Shewanella algae as recipients. LC-MS/MS will be used to quantify the levels of different antibiotics in the collected samples. We hypothesize that local water microbiota, antibiotic residues, and recipient species will affect the type of plasmids transferred. The effects of the acquired plasmids on the physiology of our bacterial models will be analyzed in experimental lab systems, and their influence on fitness and virulence in a live host will be studied by host interactions in a shrimp (Artemia)model. The project will determine common ARG plasmids circulating in European waters and their inherent properties as a fundament to understand and prevent their dissemination.