Detection of listeria monocytogenes in foodstuffs using chromogenic isolation media.

A study was carried out to compare two selective plating media commonly used to detect Listeria monocytogenes in food samples (Palcam and Oxford agar) with two more recently formulated chromogenic media (ALOA and Rapid'L.mono). A comparison was also made between the identification systems API-Listeria and Monocytogenes ID Discs. The results obtained from the analysis of 132 food samples showed that the chromogenic media allowed Listeria monocytogenes to be detected more rapidly and with higher levels of specificity and sensitivity. The efficiency of the Monocytogenes ID Discs test was confirmed, giving results comparable to those obtained with API-Listeria, but in a simpler and quicker manner.