E. Waak et al., Comparison of the ISO and IDF methods for detection of Listeria monocytogenes in blue veined cheese, INT DAIRY J, 9(2), 1999, pp. 149-155
The International Dairy Federation Revised Provisional IDF Standard 143:199
0 (1990) is compared with the ISO Draft International Standard ISO/DIS 1129
0-1 (1995) for detection of Listeria monocytogenes in inoculated samples of
the blue veined cheeses Gorgonzola and Adelost (Swedish blue mould cheese)
and in non-inoculated market cheeses of mostly soft mould cheese. The ISO
method detected L, monocytogenes significantly more frequently than the IDF
method when inoculated Gorgonzola samples were analysed. For inoculated Ad
elost, and non-inoculated market cheeses the methods were equally good. The
selective isolation media PALCAM and Oxford Listeria selective agar, were
compared for recovery of Listeria spp. Less growth of non-listeria colonies
was obtained on PALCAM agar compared to Oxford Listeria selective agar esp
ecially after the primary enrichment step of the ISO method. Consequently,
it was easier to identify and isolate growth of Listeria species from the c
heeses on the PALCAM agar. (C) 1999 Elsevier Science Ltd. All rights reserv
ed.