Members of the genus Listeria are ubiquitous and only one species is pathogenic. Listeria have been isolated from various food products including dairy products, meat, vegetables, and seafood, as well as from environmental samples taken, in particular, from food processing plants.
Listeria monocytogenes is the only species considered as pathogenic for humans. Listeriosis in humans may cause pathologies such as meningitis, septicaemia, encephalitis and abortions. Groups at risk include pregnant women, neonates, immunocompromised patients, and the elderly. Listeria monocytogenes is widespread in the environment and is a potential risk when raw, partially processed and even some fermented food are consumed.

The standard medium “par excellence”

• In accordance with the NF EN ISO 11290 standard “Horizontal method for the detection and enumeration of Listeria monocytogenes” (Amendment 2005).
• Described in the BAM (Bacteriological Analytical Manual) Chapter 10, 2003.

Simple and reliable interpretation

• All species of Listeria grow on the agar producing turquoise-blue colonies (glucosidase activity).
• An opaque halo appears around Listeria monocytogenes colonies, enabling their differentiation (phospholipase C activity).
• Listeria ivanovii, found infrequently in food matrices, also produces an opaque halo and grows on this medium at a rate that is slower and more polymorphic than L. monocytogenes.
• This selective agar medium also inhibits most other bacteria and yeasts.

Performance “one step ahead”

• Possibility to read Listeria monocytogenes after just 24 hours incubation: carefully selected ingredients ensure the performance is enhanced.
• Quality control is in accordance with NF EN ISO 11290 recommendations and follows the principle of XP CEN ISO/TS 11133-2 guidelines.
• Direct identification of characteristic isolated colonies has been validated using API Listeria without purification.
• Constant quality and the same level of performance from lot to lot is ensured with proven manufacturing processes.
• Fully validated expiry date established in real time.
• Evaluated using a range of naturally and artificially contaminated food matrices.

Multi-purpose agar

• Detection of Listeria monocytogenes.
  • According to the NF EN ISO standard detection method, another agar of any type (such as PALCAM or Oxford media) must be used in parallel to the chromogenic medium.
  • With short protocol, validated by AFNOR/16140 (BIO 12/14 - 04/05) as an alternative method for the analysis of human food products and environmental samples. Validation extension obtained in 2008 to add new identification/confirmation methods such as API Listeria without purification and several other methods including a new rapid test, RAPIDEC® Lmono.
• Enumeration of Listeria monocytogenes.
  • According to the NF EN ISO standard enumeration method.
  • With simplified protocol, validated by AFNOR/16140 (BIO 12/24 - 03/08) as an alternative and simplified method for enumeration, including all the identification/confirmation method already validated for the short validated detection method.
• Detection of Listeria spp
  • With short protocol, validated by AFNOR/16140 (BIO 12/14 - 04/05). Validation extension obtained in 2008 for Listeria spp detection including simplified confirmation methods such as: PALCAM or ID color Catalase directly on isolated colonies.
• Confirmation of positive results obtained with the VIDAS® tests (LMO2, LIS and LSX).