The occurrence, fate and potential selection of antibiotic resistance genes and bacteria in the Swiss wastewater effluents and their receiving rivers. Swiss wastewater and river microbiomes and resistomes

Treated wastewater is a point source of antibiotic-resistant bacteria, as normal wastewater 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.