University Road, Galway City, Connacht, Ireland
Ullevålsveien 68, Oslo, Oslo, Norway
Oak Park, Carlow Municipal District, Leinster, Ireland
The Project #HME-AMR
Start: | October 2020 |
Duration: | 3 years |
Domain: | Antimicrobial Resistance |
Members: | TEAGASC, NUIG- Ireland, NVI- Norway |
Contact: | Dr Kaye Burgess |
HME-AMR: Investigating the role of heavy metals in the environment as a selective pressure for the dissemination of antimicrobial resistance
A key element in managing antimicrobial resistance (AMR) in the One Health paradigm is to reduce the dissemination of resistance genes between microorganisms in the agri-food environment. A crucial mechanism for such dissemination is via horizontal gene transfer (HGT) of AMR encoding mobile genetic elements. This is particularly the case for Enterobacteriaceae where a multi-drug resistant (MDR) phenotype is increasingly being observed. This mobility shapes the resistome; the collection of all genes that directly or indirectly contributes to antibiotic resistance in a particular niche. It is recognised that a reservoir of AMR genes in the environment provides the possibility for transfer of these genes to human pathogenic bacteria via zoonotic pathways.
Selective pressures drive bacterial populations to evolve and may promote the dissemination of AMR genes, in the human and animal gut, or in the environment. However, there is limited information about the impact of selective pressures in the agri-food environment on HGT between microorganisms. One of the factors which can act as a selective pressure and can influence this HGT is the presence of heavy metals. Resistance to these metals may lead to the co-selection of antibiotic resistance genes, as antibiotic resistance genes can be located on the same genetic element as metal resistance genes. Cross resistance is also a possibility, where a heavy metal resistance mechanism such as non-specific membrane transporter may also facilitate antibiotic resistance.
Heavy metals occur ubiquitously in the agri-food environment and sometimes in high concentrations in soil. In food animal production, heavy metals such as zinc and copper are frequently added to animal feed to promote growth and health. Such heavy metals added to animal feed may not be fully absorbed from the animal gut and are excreted in faeces into the environment. Moreover, heavy metals are used to protect plants due to their fungicidal functions.
It is recognised that a One Health approach is required to tackle antimicrobial resistance. This includes the role the environment, and the food production environment in particular, plays. Very limited information is available regarding the impact of selective pressures such as heavy metals which may be present in the environment on the mobilisation of antimicrobial resistance and its potential transfer into the food chain. Therefore, this project is investigating the presence of antimicrobial resistant bacteria and assessing the bacterial resistomes in heavy metal-containing environments. In particular, the project focuses on four main objectives:
- Comparison of the resistome in zinc amended and non-amended soil used for horticultural crop production
- Comparison of the resistome in low and high metal containing soils used for dairy pasture
- Comparison of the resistome in bovine milk filters from cows grazing on grass in low and high metal areas
- Genotypic comparison with antimicrobial resistant Enterobacterales with human, environmental and animal isolates from Irish and EU reference laboratories
Project Assets
Anedda, E., Farrell, M. L., Morris, D., & Burgess, C. M. (2023). Evaluating the impact of heavy metals on antimicrobial resistance in the primary food production environment: A scoping review. Environmental Pollution. 320, 121035. DOI: https://doi.org/10.1016/j.envpol.2023.121035
Deliverable D-PhD03-1.2. (Embargoed access until Sept 2024)
Anedda, E., Madigan, G., Morris, D., & Burgess, C. (2022). Evaluating the impact of zinc application on the presence of antimicrobial resistance in spinach and its production environment. Poster presentation. ONE Conference 2022, Brussels, Belgium. 21-24th June 2022. DOI: https://doi.org/10.5281/zenodo.7377791
Anedda, E., Madigan, G., Morris, D., & Burgess, C. (2022). Assessment of the presence of antimicrobial resistant bacteria in spinach and its production environment after zinc application. Poster presentation. One Health EJP Annual Scientific Meeting (OHEJP ASM), Orvieto, Italy. 11-13th April 2022. DOI: https://doi.org/10.5281/zenodo.7377671
Anedda, E., Burgess, C, & Morris, D. (2021). A scoping review to evaluate the impact of heavy metals in the agri-food environment as selective pressure for the mobilisation of antimicrobial resistance. Poster presentation. One Health EJP Annual Scientific Meeting (OHEJP ASM), Copenhagen, Denmark. 9-11th June 2021. DOI: https://doi.org/10.5281/zenodo.7377931
Elena Anedda