TABLE 4.

Validation of CBD-MS plating with naturally contaminated food samples

Food type or parameterNo. of samples positive/no. tested (% positive)a
CBD-MS platingStandard plating method
Meat and meat products6/26 (23)5/26 (19)
Poultry9/13 (69)9/13 (69)
Fish and seafood25/92 (27)23/92 (25)
Dairy products4/110 (4)4/110 (4)
Delicatessen salads1/34 (3)1/34 (3)
Total positive (Listeria spp.)45/275 (16)42/275 (15)
Positive for L. monocytogenes28/275 (10)26/275 (9)
Relative performance (%)b10093
Total time required (h)48c96d
  • a Values were rounded to the next whole number.

  • b Relative performance was set at 100% for the system which detected the most positive samples.

  • c Selective enrichment for 22 h, CBD-MS, and plate incubation for 24 h.

  • d International IDF standard/ISO norm (selective enrichment for 48 h and plate incubation for 48 h).