Reducing antibiotic resistance in slurry

Organic fertilisers are transmitting a large number of antibiotic resistances – both resistant pathogens and individual genetic components that play a role in the development of resistances – to agricultural land. Slurry and manure fertilisers from pig and poultry farms contain a particularly large quantity and diversity of clinically relevant antibiotic resistances. We are performing tests to determine the extent to which composting or anaerobic digestion can reduce resistance. At the same time, we are investigating whether reducing resistance in fertiliser also reduces the number of resistance genes in soil and plants. We will be carrying out these investigations in Switzerland, while other research groups will be testing the same methods in five other countries.

Organic fertilisers obtained from livestock holdings and applied to fields are a key source of antibiotic resistances in the food chain. As yet, little research has been undertaken to determine how the resistances carried by fertilisers could be reduced and what impact doing so would have on resistances in the soil and plants grown for human or animal consumption.

We aim to identify methods of treating organic fertilisers so as to lower their content of antibiotic resistances, thereby reducing resistance in soil and in plants grown for human or animal consumption.

Reducing or eliminating antibiotic resistances in organic fertiliser will help to ensure that fewer resistant pathogens and resistance genes make their way into the food chain. As the methods in question are being tested in real-life conditions in the home countries of the project partners, the result is expected to be a technology developed in and applicable to international circumstances.

Intervention of antimicrobial resistance transfer into the food chain