Shiga toxin-producing Escherichia coli (E. coli STEC), including the O157 strain, poses a significant food safety risk, especially to vulnerable groups such as young children and the elderly. Eurofins Food Testing UK offers accredited microbiological testing for E. coli STEC, supporting food producers with detection of Shiga toxin genes (stx1, stx2) and pathogenic strains across raw materials, finished products, and processing environments.
Understanding E. coli STEC
E. coli is naturally found in the intestinal microbiota of humans and animals, but strains with the stx gene, which produces Shiga toxin, can cause serious illness. E. coli STEC strains capable of causing clinical disease are often referred to as EHEC (Enterohemorrhagic E. coli). These can damage the kidneys, colon, nervous system, and brain, making them a critical food safety concern across the UK and Europe.
Transmission and contamination routes
The main sources of E. Coli STEC Shiga toxin transmission include raw and undercooked food products, including
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Undercooked minced beef
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Raw milk and unpasteurised dairy products
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Raw vegetables and sprouted seeds
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Unpasteurised juices (e.g. apple juice)
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Contaminated water or flour
Contamination often occurs during slaughter, milking, irrigation, effluent from ruminant farms, or food handling or processing. Cattle and sheep are common carriers without showing symptoms. Drinking water can also be contaminated accidentally or due to a lack of adequate treatment.
Testing recommendations
Due to the high risk, self-check microbial monitoring for E. coli STEC is strongly advised for
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Ready-to-eat foods, particularly those eaten raw
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High-risk raw ingredients
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Environments with hygiene vulnerabilities
Regulatory approaches in the UK and Europe
In the UK, the detection of any STEC (Shiga Toxin-producing E. coli) in ready-to-eat (RTE) foods is considered a serious public health risk, which might necessitate action such as immediate product withdrawal or recall. For foods intended for further processing, a risk assessment determines the appropriate response.
Across Europe, there is no harmonised EU regulation for STEC risk so regulatory approaches vary, for example
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Germany: Any detection of stx genes leads to mandatory withdrawal
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Sweden and Belgium: Require the presence of both stx1/2 and eae genes for action
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Ireland, Italy, Netherlands, and Romania: Action is based on the presence of stx1 or stx2 genes in RTE foods
This diversity underscores the necessity for UK food businesses to implement tailored testing and compliance strategies, particularly when exporting to European markets.
Analytical solutions & risk management*
Eurofins offers flexible and validated methods for detecting STEC E. Coli
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stx1 and stx2 genes (Shiga toxins)
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eae gene (intimin)
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E. coli O157 and non-O157 serogroups
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Confirmatory culture and PCR
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ISO 17025-accredited results
We also provide food consultancy to support E. coli risk management
*Note: We are continuously developing new methodologies to meet evolving needs. For details on accreditation status and turnaround times for specialist microbiological testing, please contact your local Eurofins Food Testing UK laboratory as some services are delivered locally, while others may be delivered through our network of Eurofins Laboratories and Competence Centres.
Protect your consumers and comply with complex UK and European requirements for E. coli STEC, contact us or call +44 (0) 845 604 6740.
