Escherichia coli, commonly known as E. coli, is a type of bacteria that exists in the intestines of animals, including humans. Many types of E. coli are harmless, and in fact can be beneficial to the digestive system. However, certain types of E. coli can cause illness or even death. One particular class of E. coli, known as Shiga toxin-producing E. coli (STEC), can be particularly life-threatening. Here are four key facts that food processors need to know.
1. Where is E. coli found and what are the effects?
Found in foods such as raw beef and poultry, raw dairy products, leafy greens, and sprouts, E. coli can cause conditions ranging from gastrointestinal illness to life-threatening infections, particularly in higher-risk groups such as the elderly and those with weakened immune systems. E. coli O157:H7 is one STEC strain that has caused outbreaks in the United States through contaminated or undercooked food. According to the FDA, E. coli O157:H7 outbreaks have been linked to:
- Romaine lettuce from both Arizona and California.
- Leafy greens.
- Soy nut butter.
- Spring mix.
- Ready-to-eat salads.
The CDC estimates that STEC strains, including E. coli O157:H7, cause 265,000 illnesses and 30 deaths each year in the U.S.
2. How is E. coli transmitted?
In a food processing environment, E. coli O157:H7 can be transmitted through infected beef or other meats that cross-contaminate other foods via surfaces, utensils, or food handling. When this contaminated food is not properly cooked in the home or in a commercial environment, the result is an increased risk of infection. In the case of produce, contamination often occurs during cultivation, harvesting, or handling.
3. How can E. coli O157:H7 infections be prevented?
According to the World Health Organization, E. coli prevention occurs at three levels in the food supply chain: agricultural production, food processing, and food preparation. Producers of fruits and vegetables are encouraged to:
- Practice daily hygiene.
- Protect fields from contamination.
- Use treated manure.
- Reduce risk of contaminated irrigation water.
- Keep equipment clean and dry.
Meat and poultry producers are similarly encouraged to:
- Screen animals for pathogens prior to slaughter.
- Use hygienic slaughtering practices.
- Educate workers on hygienic practices.
At the household level, the risk of E. coli contamination can be significantly reduced by:
- Thoroughly cooking food.
- Washing fruits and vegetables.
- Avoiding consumption of raw or unpasteurized dairy products.
- Regularly washing hands.
Of course, many of these measures also help prevent the spread of other pathogenic bacteria, so they are generally good daily practices to adopt throughout the food handling process.
4. How can E. coli be prevented in food processing environments?
In addition to taking measures to prevent cross-contamination, manufacturers can take extra steps to treat food processing environments to reduce the spread of E. coli. The first step is creating a prevention program so that an outbreak doesn’t occur in the first place. Being proactive can save companies millions of dollars in recall costs and lost business, not to mention immeasurable brand damage.
One approach to E. coli prevention includes regular sanitizing, which reduces bacteria to safe levels without impacting the quality of the product. In a manufacturing environment, bacteria can be found on food handling surfaces, in processing equipment, on walls and ceilings, and in drains. Creating protocols that address all of these areas will help ensure that all potentially contaminated surfaces are sanitized. This includes measures such as disassembling equipment, using products that are able to adhere to vertical walls long enough for the chemicals to be effective, and ensuring that sanitizers are both diluted properly and allowed to stay on surfaces for minimum contact times.
Because sanitizers remove bacteria only to a safe level, it’s important to understand that some bacteria may remain behind. This is significant because it could lead to resistance or the development of biofilms. A 5-log reduction (99.999 percent) means that out of every one million microorganisms, 10 will survive. This might be considered a safe level, but the 10 remaining bacteria will grow over time. Regular sanitizing reduces the chances of an outbreak or the development of biofilms because bacteria are routinely reduced to a safe level.
When an outbreak does occur or biofilms develop, disinfection is required to more effectively treat the bacteria that are present in the food processing environment. In contrast to sanitizing, which lowers bacteria to safe levels, disinfecting destroys or irreversibly inactivates bacteria on hard surfaces.