Fact sheet on Escherichia coli (E. coli)

General information
Escherichia coli (E. coli) belongs to the family Enterobacteriaceae and is a natural inhabitant of the intestines of humans and animals. Therefore these bacteria regularly occur in raw animal foods. Since these organisms can survive for a long time in the environment, they are also detected in raw plant-based foods.
The occurrence of these bacteria should be significantly reduced by appropriate hygiene measures. They are an important hygiene indicator and some strains can cause severe foodborne gastrointestinal illnesses.

• More specific information on some representatives: see fact sheets for the strains EHEC / STEC / VTEC

Characteristics

• Rod-shaped bacteria
• Gram-negative
• Oxidase-negative
• Catalase-positive

Origin / Occurrence

• Natural inhabitant of the intestinal tract of humans and animals
• Because some representatives can survive for a long time in the environment, they also occur in soil, in plant-based foods and in surface water

Significance

• Hygiene indicator for fecal contamination
• Indication of inadequate production and personnel hygiene
• Survives for a long time in the environment (i.e. several contamination sources should be considered)
• Indicator for potential health hazards from some E. coli strains (e.g. STEC/EHEC) and other pathogens of fecal origin

Growth conditions

• Temperature:
  • Optimum: +30 °C to +37 °C
  • Minimum: +7 °C
  • Generally no growth above +50 °C
• pH value: growth at 4.4 to 9.0
• a_w value: growth at high water activity of at least 0.95
• Oxygen requirement: growth with and without oxygen (facultative anaerobe)

Inactivation by heating

• At +72 °C for at least 2 minutes exposure time (Attention: check core temperature)

1. Check the performance of cleaning and disinfection:
   1. Hygiene plan
   2. Execution of cleaning and disinfection e.g. dosing of disinfectant, contact time, use of appropriate and clean materials and cleaning cloths
2. Avoid moisture residues and biofilms. Ensure thorough drying of systems, equipment and surfaces
3. Train staff regarding potential errors and improvement measures
4. Repeat cleaning and disinfection
5. Verify effectiveness by visual on-site inspections, environmental tests and follow-up testing

1. Check work organization in the facility
   1. Separate work areas, equipment and utensils for raw and processed foods
   2. Separation of “clean” and “unclean” areas and activities
2. Train staff regarding potential errors and improvement measures
3. Verify effectiveness by visual on-site inspections and follow-up testing

1. Train staff regarding potential errors and improvement measures
2. Regular cleaning and disinfection of hands or regular glove changes
3. Regular changing of work clothing. Ensure cleanliness of work clothing
4. Train staff on infection control requirements
5. Verify effectiveness by visual on-site inspections and follow-up testing

1. Check incoming products at goods receipt for e.g. incoming/transport temperature, shelf life, packaging, deviations or abnormalities
2. This also applies to goods before use in production. In case of doubt, do not use the food and consult a supervisor
3. Check microbiological specifications. If necessary, initiate laboratory testing of suspicious products or request results from the supplier
4. Verify effectiveness by follow-up testing

1. Check processes, production protocols and documentation
2. Inactivation of most bacteria from a core temperature of +72 °C for at least 2 minutes. Exceptions are e.g. heat-stable spores and toxins. In these cases significantly higher temperatures and time exposure are required. Further information can be found in the respective information sheets (fact sheets)
3. Check correctness of processes and temperatures
   1. In general, holding temperatures above +60 °C are required
   2. Rapid cooling: after 3 hours a core temperature of at least +7 °C must be reached (particular caution is required for large quantities)
4. Verify effectiveness by follow-up testing

1. Request traceability of the cold chain from transport or the supplier
2. Check incoming and storage temperatures
3. Control cooling temperatures / cold chain during processing, transport and sale
4. If ageing (or too long shelf life) is suspected, perform appropriate storage tests
5. Verify effectiveness by follow-up testing

1. Maintain distance from fields with animal husbandry; keep wild animals away from fields by e.g. fences or nets
2. Water hygiene: contaminated water must not be used for irrigation. Irrigation and drainage systems must be appropriate. Regular monitoring of microbiological water quality
3. No use of microbially contaminated fertilizers in crop production
4. Personnel & work hygiene during harvest or downstream steps
5. Remove soil or contaminants by washing
6. Verify effectiveness by follow-up testing

1. Check processes, environmental conditions, production protocols and documentation
2. Verify effectiveness by follow-up testing