To isolate Listeria monocytogenes from processed meats and poultry, the following
procedure is recommended by the U.S. Department of Agriculture.
1. Add 25 g of test material to 225 mL of UVM Modified Listeria Enrichment Broth
and mix or blend thoroughly.
2. Incubate for 20-24 hours at 30°C.
3. Transfer 0.1 mL of the incubated broth to Fraser Broth. Incubate at 35°C for 26 ± 2 hours.
4. At 24 and 48 hours, streak the Fraser Broth culture to Modified Oxford Agar.
5. Incubate the Modified Oxford plates at 35°C for 24-48 hours.