Listeria monocytogenes

Listeria monocytogenes is a persistent bacteria that lurks throughout the food chain. This bacteria can survive at low temperatures and poses a serious risk to food producers, with potential contamination of end products and severe consequences for consumers. How does this bacteria pose a serious threat to food producers and consumers?

Listeria: the bacterium

Listeria is a group of bacteria found in nature. Listeria monocytogenes is a species within this group that can make you ill. It is a gram-positive, rod-shaped bacteria that can survive for extended periods under colder conditions. The bacteria can multiply at temperatures between 3 and 42°C and can therefore survive in the refrigerator. It is also found in soil, silage, water, and food. Listeria monocytogenes can cause the bacterial infection Listeriosis.

Listeria in animals

The Listeria bacteria mainly occurs in ruminants but can also be found in other mammals. Many animals carry the bacterium in their intestines without showing symptoms. When animals do show symptoms, adult ruminants often exhibit neurological signs. Young ruminants and other animals may develop septicaemia with general symptoms of illness. Animals are generally infected via the faecal-oral route (through faeces that come into contact with the mouth). Ruminants can also become infected by consuming contaminated roughage. Since Listeria is common in animals, the greatest risk for humans lies primarily in consuming raw products, such as cheeses made from unpasteurised milk, pre-packaged meat and fish products, or other animal products.

Contamination with Listeria monocytogenes

Human contamination with Listeria monocytogenes often occurs indirectly. People can become ill by consuming contaminated food. This often results in a mild infection or food poisoning, which usually resolves within a few days. However, the bacterium is dangerous for vulnerable groups. For example, pregnant women are at greater risk if they become infected, with the greatest danger being the risk of miscarriage. It is therefore crucial to take steps to prevent contamination for all consumers.

Prevention in the food industry

Listeria Monocytogenes is found in animal products, but this is not the only possible source of contamination in your process. Due to biofilm formation in water pipes, this pathogen can enter the process water. In addition to Listeria, other bacteria, moulds, and yeasts can accumulate in the biofilm, leading to cross-contamination with food. To prevent contamination with Listeria monocytogenes in your end products, you can disinfect your process water preventively. Watter offers a sustainable system that produces an effective disinfectant on-site (in-situ). Our solution is made from salt, water, and electricity. The salt and water solution is electrolysed, resulting in a disinfectant with HOCl as the active ingredient. Our disinfection solution is an excellent alternative to traditional disinfectants, as we achieve the desired log reduction with lower dosages. You can use our product for both process water and surface disinfection.