Abstract:
The discovery of IgY in chicken eggs has gained interest due to its use in
immunodiagnosis, immunotherapy and treatment of diseases. This study used eggs from
White Leghorn chicken immunized with a peptide antigen from Salmonella entrica
serovar typhi, using precipitin ring formation in radial immunodiffusion assay as the
indicator. IgY crude isolates from egg yolk was obtained by water dilution method.
Bradford assay results showed that the total protein content of these crude isolates ranged
from 1.5-7 mg /ml yolk during the egg laying period. SDS-PAGE detected the presence
of IgY and measured its purity to be about 85%-94%. Radial immnudiffusion assay was
used to determine the immunoreactivity of IgY against S. typhi. Peak diameters were
observed at 100% heat killed bacteria (-1.26 x 105 CFU/ml) and 12.5% antibody dilution.
Pearson analysis also showed that there is a strong positive correlation between the
protein content and immunospecificity of IgY against heat killed S. typhi.
Immunospecific reaction was also observed at 100%-12.5% S. typhi peptide antigen and
12.5% antibody dilution. Based on these results, IgYs in the crude isolates were
immunospecific for the antigen in Salmonella typhi.
