Spread of Antimicrobial Resistance in Wastewater Treatment Plants
Antibiotic resistance in bacteria is a major threat to global health. Several strains of bacteria are already resistant to every therapy available and new drug development is falling behind. Wastewater-AMR is searching for ways to stop antimicrobial resistance from spreading in an unlikely place: the wastewater treatment plant.
These treatment plants are hubs of bacterial gene-swapping where potentially antibiotic-resistant bacteria from our bodies that arrive with the wastewater can share their DNA with bacteria from the soil and water that the treatment plant relies on to help breakdown the waste. Unfortunately, it is too expensive and energy intensive to fully sterilize all the effluent from these plants so it still contains some of these newly-resistant bacteria when it’s released into waterways and oceans. From there, they can make their way into animals and eventually into people and cause serious, un-treatable, illness.
To figure out an efficient way to stop resistance genes from spreading, the researchers use their expertise in systems engineering and cellular biology in collaboration with labs in Sweden and Denmark. They built a mathematical model based on scientific literature that describes the bacteria-driven processes of breaking down waste and the spread of resistance genes from human bacteria to the treatment plant’s native bacteria. The extensive model also includes all the pipes, pumps, and connections that make up the treatment plant. Now, a local wastewater treatment plant is helping them build a scaled-down plant in their lab to generate experimental data to tune their model.
They begin with putting sludge from the treatment plant, the smelly semi-solid waste from the sewers, into their lab-scale system. They add their own resistant bacteria engineered with fluorescent markers that let them follow how the resistance genes spread through the system under different conditions. This experiment will give the researchers the parameters they need for their model and identify critical nodes they can target to disrupt resistance-sharing.Wastewater-AMR expects to have their new experimentally-based model ready by the end of the year. Their results will be shared publicly, and their study is designed to integrate easily with existing standards and recommendations for wastewater treatment plants. Understanding how resistance spreads through bacteria at these plants is a small but crucial step in keeping us safe from antimicrobial resistant bacteria.
Lund University Sweden, Department of Clinical Sciences (Rolf Lood), Lund University Sweden, Department of Biotechnology (Bo Mattiasson), Statens Serum Institute Denmark, Bacteriology Reference Department (Kurt Fuursted)