The problem

Drug-resistant bacteria can spread from manure into soil and from there potentially into the human food chain.

The project

Researchers at Maynooth University and Teagasc tracked bacteria and genes that make the bugs resistant to drugs in pig manure that was either composted or untreated and then spread on grass, a typical practice on farms in Ireland.

The outcomes

We now know that:

  • Composting is an effective way to reduce drug-resistant bacteria in manure
  • The widespread practice of delaying animals from grazing where manure (whether composted or not) has been spread reduces the spread of antimicrobial resistance
  • The microbes (bacteria, fungi etc.) present on grass may help to reduce the spread of antimicrobial resistance in the food chain.

Professor Fiona Walsh, Kathleen Lonsdale Institute for Human Health at Maynooth University, says:

“We showed that the current practices of treating manure and having a gap before allowing animals graze the grass reduces the levels of antimicrobial resistance on the grass, which is good news. This is the first study to show the importance of farmland grass in understanding the movement of antimicrobial resistance from the manure to the environment.”

Compost, time, and grass – how to tackle drug-resistant bacteria in the food chain” is part of a wider collection of success stories across four themes from this year’s annual Health Research in Action. Download the full publication.