Detection and identification ofListeria monocytogenes in foodby PCR and oligonucleotide-specificcapture plate hybridization

This paper reports on an ELISA-based detection method for PCR-amplified Listeria monocytogenes iap gene fragment. During PCR, a label(digoxigenin-11-dUTP)is incorporated in the amplicon. After amplification, the product obtained is hybridized in streptavidin-coated microtitre plates prepared with biotinylated-specific oligonucleotide as a DNA probe, and then an enzyme immunoassay reveals the specifically bound complex, which permits identification of L. monocytogenes. A total of 48 food samples were tested to validate the method involved. The PCR-oligonucleotide specific capture plate hybridization (OSCPH) is easily applicable and much faster than traditional detection of L. monocytogenes in food. The hybridization in microtitre plates is also more sensitive than routine agarose gel electrophoresis.