Food Testing Lab - Listeria monocytogenes

Listeria is an organism that is ubiquitous in the environment. Unlike some other food related pathogens, it is not disseminated from animals. For high-risk populations (the very old, the very young, pregnant, and immunocompromised) a very little amount of Listeria in food can be highly dangerous. Listeria monocytogenes is the most pathogenic of the species.

L. monocytogeneshas been associated with such foods as raw milk, supposedly pasteurized fluid milk, cheeses (particularly soft-ripened varieties), ice cream, raw vegetables, fermented raw-meat sausages, raw and cooked poultry, raw meats (all types), and raw and smoked fish. Its ability to grow at temperatures as low as 3°C permits multiplication in refrigerated foods.

This method detects the presence or absence of the bacterium. A confirmation charge may be incurred in cases of Presumptive Positive screens. 

50g (250g for 125g testing) minimum sample is recommended. Environmental surface samples can also be analyzed.

EMSL Test Codes:

Listeria monocytogenes:

• VIDAS (LMX-AOAC 2013.11): F159 (Environmental), F237 (25g), F723 (125g)
• BAX (AOAC-RI 121402): F229 (Environmental), F188 (25g)

Sample retention time – 30 days, unless highly perishable