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 examine d using Oxford (Oxoid) and PALCAM (Merck) listeria-selective agars. Se ven (13%) samples were positive for Listeria monocytogenes and 14 (27% ) samples were positive for other Listeria species, while 31 (59%) sam ples were negative for Listeria species. The effectiveness of PALCAM a nd Oxford medium for the isolation of L. monocytogenes from the meat s amples was compared. PALCAM medium was consistently more effective in suppressing other micro-organisms thus enhancing the possibility of de tecting Listeria species present in low numbers. The isolation of List eria species for identification was also easier using PALCAM medium.