DEVELOPMENT OF A RANDOM AMPLIFICATION OF POLYMORPHIC DNA TYPING METHOD FOR LISTERIA-MONOCYTOGENES

The 10-mer primer OPM-01 (5'-GTT GGT GGC T-3') was used to generate ra ndom amplification of polymorphic DNA (RAPD) profiles by polymerase ch ain reaction for 91 strains of Listeria monocytogenes from raw milk, f ood, and veterinary, medical, and food-environmental sources. The prof iles obtained contained 1 to 10 bands within the molecular size range of 0.5 to 5.0 kbp. Reproducibility was enhanced by annealing at low st ringency and introducing a 1-min ramp time between annealing and exten sion temperatures. Thirty-three RAPD profiles were observed, with spec ific profiles being observed for strains from each source. RAPD profil es allowed discrimination within serogroups, although five RAPD profil es which were not confined to one serotype were found. Within food str ains, one RAPD profile was more common than others, suggesting this to be a common type among strains from this source.