Modelling the impact of wastewater flows and management practices on antimicrobial resistance in dairy farms

Henry Todman; Richard Helliwell; Liz King; Adam Blanchard; Charlotte J Gray-Hammerton; Steven P Hooton; Michelle Baker; Jean Margerison; Paul Wilson; Christine E R Dodd; Carol Morris; Sujatha Raman; Chris Hudson; Jan-Ulrich Kreft; Jon L Hobman; Theodore Kypraios; Dov J Stekel

doi:10.1038/s44259-024-00029-4

Modelling the impact of wastewater flows and management practices on antimicrobial resistance in dairy farms

NPJ Antimicrob Resist. 2024;2(1):13. doi: 10.1038/s44259-024-00029-4. Epub 2024 May 14.

Authors

Henry Todman¹, Richard Helliwell^{2

3

4}, Liz King¹, Adam Blanchard⁵, Charlotte J Gray-Hammerton^{1

6}, Steven P Hooton^{1

7}, Michelle Baker^{1

5}, Jean Margerison¹, Paul Wilson¹, Christine E R Dodd¹, Carol Morris², Sujatha Raman^{4

8}, Chris Hudson⁵, Jan-Ulrich Kreft⁹, Jon L Hobman¹, Theodore Kypraios¹⁰, Dov J Stekel^{1

11}

Affiliations

¹ School of Biosciences, University of Nottingham, Sutton Bonington Campus, College Road, Loughborough, Leicestershire LE12 5RD UK.
² School of Geography, University of Nottingham, University Park Campus, Nottingham, NG7 2RD UK.
³ School of Sociology and Social Policy, University of Nottingham, University Park Campus, Nottingham, NG7 2RD UK.
⁴ Ruralis, University Centre Dragvoll, N-7491 Trondheim, Norway.
⁵ School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD UK.
⁶ Ineos Oxford Institute for Antimicrobial Research, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE UK.
⁷ Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester, LE1 7RH UK.
⁸ Australian National Centre for Public Awareness of Science, Australian National University, Canberra, Australia.
⁹ Institute of Microbiology and Infection & School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK.
¹⁰ School of Mathematical Sciences, University of Nottingham, University Park Campus, Nottingham, NG7 2RD UK.
¹¹ Department of Mathematics and Applied Mathematics, University of Johannesburg, Auckland Park Kingsway Campus, Rossmore, Johannesburg South Africa.

Abstract

Dairy slurry is a major source of environmental contamination with antimicrobial resistant genes and bacteria. We developed mathematical models and conducted on-farm research to explore the impact of wastewater flows and management practices on antimicrobial resistance (AMR) in slurry. Temporal fluctuations in cephalosporin-resistant Escherichia coli were observed and attributed to farm activities, specifically the disposal of spent copper and zinc footbath into the slurry system. Our model revealed that resistance should be more frequently observed with relevant determinants encoded chromosomally rather than on plasmids, which was supported by reanalysis of sequenced genomes from the farm. Additionally, lower resistance levels were predicted in conditions with lower growth and higher death rates. The use of muck heap effluent for washing dirty channels did not explain the fluctuations in cephalosporin resistance. These results highlight farm-specific opportunities to reduce AMR pollution, beyond antibiotic use reduction, including careful disposal or recycling of waste antimicrobial metals.

Keywords: Antimicrobial resistance; Computational models.