Mathematical modelling of antimicrobial resistance in agricultural waste highlights importance of gene transfer rate

Baker, Michelle; Hobman, Jon L.; Dodd, Christine E.R.; Ramsden, Stephen J.; Stekel, Dov J.

Abstract

Antimicrobial resistance is of global concern. Most antimicrobial use is in agriculture; manures and slurry are especially important because they contain a mix of bacteria, including potential pathogens, antimicrobial resistance genes and antimicrobials. In many countries, manures and slurry are stored, especially over winter, before spreading onto fields as organic fertilizer. Thus these are a potential location for gene exchange and selection for resistance. We develop and analyze a mathematical model to quantify the spread of antimicrobial resistance in stored agricultural waste. We use parameters from a slurry tank on a UK dairy farm as an exemplar. We show that the spread of resistance depends in a subtle way on the rates of gene transfer and antibiotic inflow. If the gene transfer rate is high, then its reduction controls resistance, while cutting antibiotic inflow has little impact. If the gene transfer rate is low, then reducing antibiotic inflow controls resistance. Reducing length of storage can also control spread of resistance. Bacterial growth rate, fitness costs of carrying antimicrobial resistance and proportion of resistant bacteria in animal faeces have little impact on spread of resistance. Therefore effective treatment strategies depend critically on knowledge of gene transfer rates.

Citation

Baker, M., Hobman, J. L., Dodd, C. E., Ramsden, S. J., & Stekel, D. J. (2016). Mathematical modelling of antimicrobial resistance in agricultural waste highlights importance of gene transfer rate. FEMS Microbiology Ecology, 92(4), Article fiw040. https://doi.org/10.1093/femsec/fiw040

• Journal Article Type: Article
• Acceptance Date: Feb 19, 2016
• Online Publication Date: Feb 22, 2016
• Publication Date: Apr 1, 2016
• Deposit Date: Apr 6, 2016
• Publicly Available Date: Apr 6, 2016
• Journal: FEMS Microbiology Ecology
• Print ISSN: 0168-6496
• Electronic ISSN: 1574-6941
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 92
• Issue: 4
• Article Number: fiw040
• DOI: https://doi.org/10.1093/femsec/fiw040
• Keywords: Antimicrobial resistance, AMR, horizontal gene transfer, mathematical model, dairy slurry
• Public URL: https://nottingham-repository.worktribe.com/output/777479
• Publisher URL: http://femsec.oxfordjournals.org/content/92/4/fiw040
• Related Public URLs: http://femsec.oxfordjournals.org/
• Additional Information: This is a pre-copyedited, author-produced PDF of an article accepted for publication in FEMS Microbiology Ecology following peer review. The version of record Michelle Baker, Jon L. Hobman, Christine E. R. Dodd, Stephen J. Ramsden, Dov J. Stekel. Mathematical modelling of antimicrobial resistance in agricultural waste highlights importance of gene transfer rate is available online at: http://femsec.oxfordjournals.org/content/92/4/fiw040.