CFA Briefing – Relevance of generic E coli (inc testing issues) to food safety

Escherichia coli (E. coli) is a bacterium commonly found in the gut of humans and warm-blooded
animals. Most strains of E. coli are harmless and some provide many health benefits to the host; for example,
they prevent colonisation of the gut by harmful pathogens.

However, there are small groups of E. coli, referred to as pathogenic E. coli, that can cause severe disease in
humans, which are well known to be transmitted by food and/or water and have been implicated in major
foodborne outbreaks worldwide e.g. radish sprouts in Japan, sprouted seeds in Germany and France, raw / undercooked
beef products in the UK and USA.

This briefing note looks at the relevance of generic E. coli to food safety referring to fresh produce and is also relevant to all food types.

With sections including transmission, testing and prevention it concludes:

  • A positive for E. coli O157 alone may not cause illness.
  • The stx (Shiga toxins) gene has to be isolated in an E. coli, usually with a gene for attachment for the isolate to cause serious illness.
  • All parties agree with the confirmed stage of the method, but FSA’s decision to call isolation of stx alone as presumptive is misleading.
  • Action required in the event of a presumptive result is inappropriate and not possible for the industry.
  • Food safety can only be controlled by routinely testing for indicator organisms e.g. generic E. coliĀ and monitoring trends to proactively prompt investigation.
  • HACCP and PRPs are paramount, supported by environmental and product monitoring.

 

CFA 057 22 Briefing paper – relevance of generic E coli (inc testing issues and STEC) to food safety