This technique could lead to relatively rapid and inexpensive detection of SE in whole eggs by saving enrichment media
and reducing the incubation time. However, it has been reported that some SE strains did not multiply above 106 cells/ml in liquid whole egg after 24 h incubation at 37 jC without iron supplementation. There fore when liquid whole eggs are incubated without enrichment broth, a longer incubation time and iron supplementation would be required to allow SE to multiply to reach the cell density necessary for efficient detection. Although egg contents provide excellent nutrients for SE growth, use of enrichment broth helps maximize SE growth (Gast and Holt, 1998).