Fraser method. Following AFNOR V08-
055. The enrichment broth half-Fraser was prepared
using Fraser Broth Base (Oxoid, Madrid, Spain),
supplemented with a half of the Selective Supplement
Fraser (nalidixic acid 20 mg/l and acriflavine chlorhidrate
25 mg/l). For the first enrichment, inoculated
broth was incubated for 24 h at 30F1 jC, and then
0.1 ml was transferred to a tube with 10 ml of the
second selective enrichment Fraser, which was prepared
adding the total vial of selective supplement.
After 24 and 48 h of incubation at 30F1 jC, the
second enrichment was plated onto Palcam selective
agar.