COMPARATIVE-STUDY OF 2 PLATING MEDIA (PALCAM AND OXFORD) FOR DETECTION OF LISTERIA SPECIES IN A RANGE OF MEAT-PRODUCTS FOLLOWING A VARIETY OF ENRICHMENT PROCEDURES

Fifty-two different varieties of sausage, salami and pate were examined using Oxford (Oxoid) and PALCAM (Merck) listeria-selective agars. Seven (13%) samples were positive for Listeria monocytogenes and 14 (27%) samples were positive for other Listeria species, while 31 (59%) samples were negative for Listeria species. The effectiveness of PALCAM and Oxford medium for the isolation of L. monocytogenes from the meat samples was compared. PALCAM medium was consistently more effective in suppressing other micro-organisms thus enhancing the possibility of detecting Listeria species present in low numbers. The isolation of Listeria species for identification was also easier using PALCAM medium.