Listeria monocytogenes dosage (by research)

The detection of Listeria monocytogenes is an essential microbiological analysis to guarantee food safety. This pathogenic bacterium, responsible for listeriosis, can grow at refrigerated temperatures and persist in industrial environments, making its detection crucial in ready-to-eat products, refrigerated foods, and food production areas.

Listeria monocytogenes detection method aims to identify the presence or absence of the bacteria in a sample, in accordance with European regulatory requirements (Regulation (EC) No. 2073/2005). Unlike enumeration, this qualitative approach allows for confirmation of contamination even at very low levels.

Objective of the analysis

This microbiological research is essential for:

• Check for the absence of Listeria monocytogenes in food products before they are placed on the market.
• Ensure compliance with the microbiological criteria defined by European regulations.
• Ensuring the health safety of products intended for vulnerable populations (infants, pregnant women, the elderly).
• Monitor the hygiene of production lines and contact surfaces.
• Prevent batch recalls and preserve the brand's reputation.

The analysis is integrated into self-monitoring plans, HACCP protocols and microbiological quality audits.

Analytical methods

At YesWeLab, the search for Listeria monocytogenes is carried out according to the ISO 11290-1 , the reference method for the qualitative detection of the bacterium in food and environmental samples.

Testing on specific culture media:
The sample is first subjected to a selective enrichment phase, designed to promote the growth of Listeria monocytogenes while inhibiting other bacteria. After incubation, the presence of typical colonies is confirmed on selective media, then by biochemical or molecular tests.

PCR (Polymerase Chain Reaction)
Real-time PCR is a rapid and sensitive method for detecting Listeria monocytogenes in samples. This technique is used in addition to, or as a replacement for, culture, providing faster results (24 to 48 hours) and increased sensitivity.

sequencing
(NGS) for in-depth analysis allows for the precise identification of Listeria and the tracing of their origin. This approach is used in research and development, as well as for cross-contamination studies and genomic traceability.

All analyses are carried out in ISO 17025 accredited laboratories and according to validated protocols guaranteeing the reliability and reproducibility of the results.

Industrial applications

The search for Listeria monocytogenes concerns a wide range of sectors:

• Dairy products (cheeses, raw milk, yogurts)
• Ready-to-eat deli meats and meats
• Seafood products (smoked fish, frozen fish)
• Unpasteurized fruits, vegetables, salads and juices
• Processed plant-based products and prepared meals
• Environmental samples (water, surfaces, work atmospheres)

This analysis is particularly recommended for products with a long shelf life or for consumption without prior cooking.

Affected matrices

• Ready-to-eat foods
• Refrigerated fresh produce
• Ingredients of animal or plant origin
• Industrial surface and air samples
• Agri-food production environments

Recommended Related Analyses

For comprehensive microbiological testing, YesWeLab recommends combining the following:
Listeria monocytogenes count (by enumeration) – to accurately quantify microbial contamination;
Salmonella spp. testing – another major foodborne pathogen;
Enterobacteriaceae enumeration – a general indicator of hygienic contamination;
and Coliform enumeration – useful for assessing potential fecal contamination.

Why choose YesWeLab?

YesWeLab relies on a network of partner laboratories specializing in food microbiology, accredited to ISO 17025 and equipped for the rapid detection of foodborne pathogens. We support manufacturers in their regulatory controls, the validation of cleaning processes, and environmental monitoring.

Our digital platform allows you to centralize your analytical needs, track your samples and receive your results in a simple, fast and secure way.