Treated wastewater is a point source of antibiotic resistant bacteria, as normal waste water treatment facilities do not remove all resistant bacteria. Resistant bacteria released into streams and rivers from treated wastewater represent a risk for humans. In order to assess this risk we need to understand how antibiotic resistance spreads in bodies of water and how stable it is in this medium.
This project is focused on how this resistance behaves and where humans may come into contact with it. We are looking at which bacteria bearing which kinds of resistance pass into Swiss streams and rivers in this way and where they can be found. We are paying special attention to aquatic animals, sediments and so-called biofilms: layers of bacteria on the surface of water sediment. We are also recording the distances over which resistance is transported and how robust it is. This information will enable us to develop models to predict the resistance burden of flowing waterways along their courses. The mission is to identify places in which humans could come into contact with resistance from waste water treatment facilities. Our data and models will provide a basis for decisions and actions that will make it possible to control the spread of antibiotic resistance through flowing waterways.