PALCAM Agar

PALCAM Agar is a selective medium used for the differentiation and isolation of Listeria monocytogenes and other Listeria, from milk and cheese, as well as in other food products, even high contaminated. The media can be used as a second media of choice in the context of the directives concerning the detection of Listeria monocytogenes in food microbiology. PALCAM agar can also be used as a confirmation test for Listeria spp using the COMPASS® Listeria method.

Principles

• Peptones and yeast extract favor the excellent growth of Listeria
• Glucose and starch are the energy sources for microbial development
• Sodium chloride maintains osmotic balance
• Listeria hydrolyze esculin to glucose and esculetin, the latter compound forming a black complex with ferric ions supplied by ferric citrate
• Accompanying microflora are inhibited by lithium chloride, ceftazidime, polymyxin, and acriflavine
• Fermentation of mannitol by contaminating bacteria that may grow causes phenol red to turn yellow, thereby orienting the diagnosis