Pathogen Persistence from Paddock to Plate

Consumers naturally expect that the vegetables they buy are safe to eat, so free of any bacteria which could make them sick.

However, the growing environment creates challenges. Organic supplements used to maintain healthy soils, and water used to irrigate crops, can potentially contain pathogenic bacteria such as E. coli, Salmonella and Listeria.

The vegetable industry needs research-based guidelines on how to produce and supply crops safely. This includes understanding what organic supplements can be used, and how potential risks can be managed to ensure produce is safe to eat.

Hort Innovation, together with the vegetable industry, recently completed a study on the survival of human pathogens in soil and irrigation water, and on leafy vegetables. The project was led by the Fresh Produce Safety Centre, in conjunction with Applied Horticultural Research, Freshcare and the University of Sydney.

The project sought to answer two key questions:

1. If manures are added to soil, how long does it take for any human pathogens to die off to environmental levels?
2. What happens when water contaminated with human pathogens is used to irrigate leafy vegetables?

Factsheets and guidelines

Two short factsheets have been produced which summarise the key findings. These are aimed at vegetable producers and explain how to manage risks from compost and from irrigation water:

Factsheet – Reducing Food Safety Risks From Pre-harvest Water

Factsheet – Reducing Food Safety Risks From Manures

Also available are more detailed guidelines on how to manage risks from compost and from irrigation water. These are aimed at supply chain managers and regulators:

Reducing Food Safety Risks From Pre-harvest Water

Using Manures to Grow Vegetables – A Guide to Reducing Risk

Other resources:

• The report of the Hort Innovation VG16042 project is available here.
• Journal article by Dr Jenny Ekman and others, Persistence of human pathogens in manure-amended Australian soil used for production of leafy vegetables, Agriculture, vol 11, issue 1, 28 December 2020, is available here.
• Article by Dr Jenny Ekman, Pathogen Persistence on Leafy Vegetables, Vegetables Australia, 18 September 2020 is available here.

* Hort Innovation (HI), Applied Horticultural Research Pty Ltd (AHR), Fresh Produce Safety Centre (FPSC), Freshcare (FC) and the University of Sydney (USyd) make no representations and expressly disclaims all warranties (to the extent permitted by law) about the accuracy, completeness, or currency of information in this fact sheet. Users of this material should take independent action before relying on its accuracy in any way. Reliance on any information provided by HI, AHR, FPSC, FC or USyd is entirely at your own risk. HI, AHR, FPSC, FC and USyd are not responsible for, and will not be liable for, any loss, damage, claim, expense, cost (including legal costs) or other liability arising in any way (including from HI, AHR, FPSC, FC or USyd or any other person’s negligence or otherwise) from your use or non-use of information from project VG16042 Pathogen Persistence from Paddock to Plate or from reliance on information contained in this material or that HI, AHR, FPSC, FC or USyd provides to you by any other means.