It’s likely that you’ve heard about outbreaks of Listeria in the news lately. Here at Puritan, it’s our goal to educate our valued customers and readers about the dangers of this bacteria, as well as the illness it causes. With the proper steps, food production facilities can ensure that their equipment and food is free of this dangerous bacteria.
Listeria is a unique bacteria which causes an illness called Listeriosis. This bacteria is unique in that it can survive, and even grow on refrigerated food. Without proper testing of food preparation and processing facilities, listeria can be easily overlooked because contaminated food looks normal, smells and even tastes normal!
What is Listeria?
The numerous outbreaks of listeria in recent years have been attributed to the poor sanitation programs in food processing plants. Contamination occurs when cooked or pasteurized food comes in contact with an unsanitized surface before it is packaged. Examples of these surfaces include filling equipment, conveyors, slicers, dicers, blenders, and gloves. To minimize the risk of product contamination, it is necessary to identify at what step of the food processing the exposed food is most likely to become contaminated. These surfaces are referred to as the “primary” or high-risk environment, but listeria can also be found in other parts of a food processing facility, including walk-in refrigerators, warehouses, and washrooms. Rarely, listeria can also be found in drains, floors, walls, ceilings, trolleys, and cleaning equipment.
The Dangers of Listeriosis
If a food production or processing facility packages and distributes food contaminated with listeria, those who eat it are at risk for listeriosis. Most commonly, people get listeriosis by eating contaminated deli meat or vegetables, or unpasteurized milk and dairy products. Common symptoms include fever, stiff neck, dizziness, vomiting, and diarrhea. The illness worsens quickly and can even become fatal in pregnant women, older adults and people with weak immune systems. Unfortunately, it often takes an outbreak of illness for a food processing facility to realize it has listeria contamination. This delay puts people’s lives at risk, and could be prevented if facilities take proper precautions.
Sanitation and Sampling
Since listeria can be found in so many places in a facility, it’s imperative for any facility that produces or processes food to implement thorough environmental monitoring and sanitation programs. Swab sample collection has become the standard practice for sanitation monitoring in food processing plants, identifying not only listeria, but other foodborne pathogens as well. In order to keep your facility safe and healthy, be sure to stock the right products to ensure your samples are accurate. Selecting the right environmental transport medium and the appropriate sampling collection device will help keep your facility clean and safe.
Choose Products You Can Rely On
Choosing the right sampling swab is imperative for fast and accurate sampling of all surfaces in your food processing facility. Experts recommend a large, firm, foam-tipped swab like those found in our EnviroMax®, (dry)/EnviroMax Plus® (pre-moistened) sampling swabs. The benefits of foam-tipped swabs for food safety testing are their large tips, which increases sample and elution counts and their rigid paddle-like design which allows for a firm and even application.
Environmental sampling kits like Puritan’s ESK® Sampling Kits are easy to use and recommended for environmental monitoring in all types of food product facilities. Available with four pre-filled options (Neutralizing Buffer, Buffered Peptone Water, Leetheen Broth, and Butterfield’s Solution) all available in 4ml or 10ml configurations. For ease of use, the kit features a swab, which is tightly secured inside the screw cap, designed to sample a variety of surfaces including equipment and hard-to-reach areas.
Follow the step-by-step guide below on how to swab for Listeria using Puritans' ESK® Sampling Kits.
- Use an aseptic technique to peel open the pouch.
- Determine which surface you intend to sample. If you’re sampling a flat surface, a sterile square sampling template may help.
- Carefully, remove the cap of the vial with the pre-moistened swab attached.
- Hold the swab at a 30° angle and wipe the sample area using a back and forth motion, rotating the swab as you wipe.
- Return the swab to the vial containing the rinse solution, the screw the cap closed until tight.
- Transfer the sample to the laboratory for analysis within 4 hours. If you aren’t able to process the sample immediately, refrigerate at 2 - 4°C, for up to 24 hours until processed.
Using stringent sanitation practices and following an environmental sampling program, while using the right products, will help food processing and production facilities reduce contamination of listeria, protect the health of their customers, and help maintain their reputation for high-quality food.