Comparison of the Listeria-Tek ELISA kit with cultural procedures for the detection ofListeria species in foods

Abstract The abilities of conventional cultural procedures to detect Listeria spp. inoculated into foods were compared to the Listeria-Tek ELISA kit. Three strains of L. monocytogenes and one of L. ivanovii were separately inoculated into either soft ripened (Camembert) cheese or roast chicken. The inoculation levels used were either 0·5–2 or 50–200 Listeria g −1 food. Similar results were produced by all methods. The best procedures were cultural procedures using enrichment in MOPS-buffered enrichment broth. UVMI-Fraser enrichment broths and the ELISA kit following this latter procedure. All three techniques recovered 97·5% of the inoculated strains. Of the agar media tested, Listeria selective medium (Oxford formulation) was superior to either modified McBrides agar or lithium chloride-phenylethanol-moxalactam (LPM) agar. Overall, the Listeria-Tek kit procedure produced results as good as the best cultural procedures used.