Transmission of antibiotic resistance plasmids in sewage

The rise of antibiotic-resistant bacterial pathogens is a major threat to public health. Environmental bacteria play an important role by providing a source of antibiotic resistance genes that can be horizontally transferred to pathogens, which often involves the acquisition of resistance plasmids. Sewage environments, harboring a mixture of environmental and pathogenic bacteria as well as resistance plasmids have been pointed out as hotspots for such development. This project will assess the inductive effect of the complete mixtures of antimicrobials present in different types of sewage (raw hospital and municipal as well as treated sewage) on plasmid transfer in bacterial sewage communities. We will also determine how pre-carriage of different plasmids affect acquisition of additional plasmids and map dissemination of transferred plasmids in the sewage communities. The project is expected to provide guidance for the decision-making process whether, and if so where, additional treatment of sewage should be implemented regarding the risk for antibiotic resistance dissemination.