News
Sep 1, 2025 - Foods
MultipleRecallsDueToListeria-HygieneMeasuresAndChallengeTestsEspeciallyImportant
In recent weeks, several aspic-coated fish products have been recalled in Germany after Listeria monocytogenes was detected. Products from both a food manufacturer and a trading company were affected. In Switzerland, listeria also appeared in ready-to-eat foods such as soft cheese.
Listeria can be well controlled through targeted checks, good hygiene, and challenge tests. Manufacturers of ready-to-eat products should regularly review their processes and take risks seriously to ensure food safety in the long term.
Health Risks from Listeria monocytogenes
Listeria monocytogenes is a pathogenic bacterium that is particularly dangerous for pregnant women, newborns, the elderly, and immunocompromised individuals. An infection can cause mild flu-like symptoms or gastrointestinal issues, but in severe cases can lead to meningitis, sepsis, or miscarriages.
Causes and Risk Factors
Listeria mainly occurs in ready-to-eat products that contain animal ingredients or have been processed under unfavorable storage and production conditions. Main causes of contamination include: hygiene deficiencies in production
Insufficiently validated cleaning processes
Lack of awareness of food safety
Seasonal conditions such as high temperatures and humidity, as well as increased monitoring, also contribute to the detection of listeria. For manufacturers of perishable, ready-to-eat foods, challenge tests with Listeria monocytogenes are a key tool. These tests provide an indication of whether listeria can multiply in food during its shelf life. This is particularly important for two reasons:
Due Diligence: Every food business operator must ensure that their products pose no health risk until the end of their shelf life.
Evaluation of manufacturing processes: Since listeria is widespread in the environment, contamination cannot be completely ruled out. Challenge tests indicate whether the product composition or storage conditions promote growth. If so, hygiene and safety measures in production must be even stricter.
We recommend manufacturers regularly test ready-to-eat products for Listeria monocytogenes and conduct so-called challenge tests during product development to realistically assess the bacteria's growth potential.
In our laboratory, we conduct challenge tests with Listeria monocytogenes and other microorganisms such as Salmonella. We provide quick and reliable results and are happy to advise you on all matters related to food safety.
Our customer advisors are happy to assist you.