Environment and Rural Affairs Monitoring & Modelling Programme - ERAMMP Report-55: Evidence Review on the Entry and Spread of Antimicrobial Resistance (AMR) in the Rural Water Environment in Wales

Antimicrobials (antivirals, antibacterials, antifungals, antiprotozoals, anthelmintics) represent a fraction of all chemicals that are known to select for or aid in the dispersal of ARGs. The chemicals that drive AMR, i.e., antimicrobial resistance-driving chemicals (ARDCs), include metals, biocides, pesticides and many other environmental pollutants. Areas of significant anthropogenic impact can be areas of elevated AMR, including manufacturing and industry discharge, agriculture, municipal wastewater (wastewater treatment plants [WWTPs], combined-sewer outfalls, sewage sludge) and meat animal, egg, sport animal and dairy production activities (feed, chemotherapy, biosecurity, manure, slurry). Concentrations of ARDCs that do not kill bacteria (i.e. sub-lethal concentrations) have been shown to be sufficient to drive the selection and mobilisation of ARGs in many environmental compartments, e.g., freshwater and soils, as would also be the case in humans, e.g., the gut. In addition to chemical pollution, environmental pollutants that can increase the dissemination of ARGs represent a major mechanism for ARG dissemination, particularly from major human and animal waste sources such as wastewater and meat animal production.