Rose Collis receives 2023 AgResearch Student Award for article on AMR

19 October 2023

Prevalence and distribution of extended-spectrum β-lactamase and AmpC-producing Escherichia coli in two New Zealand dairy farm environments.

Rose received the Award for work undertaken when she was a PhD student enrolled through Massey University’s School of Veterinary Science and co-funded by a PhD scholarship from the Centre, the AgResearch Food Integrity SSIF programme, and the Massey University School of Veterinary Science post-graduate research fund. 

The award is “in recognition of the science impact of a meritorious student publication accepted for publication within the last three years”. The award includes support to attend an international conference.

Summary of the publication*

Antimicrobial resistance is a global threat to human and animal health, with the misuse and overuse of antimicrobials being suggested as the main driver of resistance. Multi-drug resistant Enterobacteriaceae, particularly extended-spectrum β-lactamase (ESBL)- and AmpC-producing Escherichia coli, are of concern to human and animal health. In a global context, New Zealand (NZ) is a relatively low user of antimicrobials in food-producing animals. However, the role antimicrobial usage on pasture-based dairy farms, such as those in NZ, plays in driving the spread of antimicrobial resistance within the dairy farm environment remains equivocal.

This paper explores the prevalence and distribution of ESBL- and AmpC-producing E. coli in farm environmental samples collected over a 15-month period from two NZ dairy farms with different management practices. The study found a low sample level prevalence of ESBL-producing E. coli. ESBL- and AmpC-producing E. coli were isolated from faeces and farm dairy effluent during months with varying levels of antimicrobial use, but not from bulk tank milk or soil from recently grazed paddocks. Hybrid assemblies using short- and long-read sequence data enabled the assembly of nine plasmids from six E. coli strains, including one plasmid co-harbouring 12 antimicrobial resistance genes, and bacteria carrying such plasmids pose a risk to public and animal health.

This study revealed a low prevalence of ESBL-producing E. coli on two conventional NZ dairy farms, which is important for the country's reputation as a food exporter and for maintaining responsible farming practices (e.g. promoting prudent antimicrobial stewardship). Antimicrobial resistance is a burden for human, animal and environmental health and requires a holistic ‘One Health’ approach to address.

*Publication information

Collis RM, Biggs PJ, Burgess SA, Midwinter AC, Brightwell G, Cookson AL. Prevalence and distribution of extended-spectrum β-lactamase and AmpC-producing Escherichia coli in two New Zealand dairy farm environments. Frontiers in Microbiology. 2022;13. doi: 10.3389/fmicb.2022.960748.

This article was as a part of the Research Topic: Women in Antimicrobials, Resistance and Chemotherapy: 2022