Laying Hen’s Primary Immune Response to Staphylococcal Protein A (SpA)

Our aim was to provide information about the production of Egg White Immunoglobulin (EWIg) with specificity to Staphylococcal protein-A, a surface antigen of Staphylococcus aureus and to study the inhibition of this bacterium growth in pre- and post-immunized hens. A sandwich Enzyme-Immunosorbent Assay (ELISA) showed a large concentration of anti-SpA antibodies in the eggs from hens immunized with protein A. The titer of these antibodies was at least 5 to 6-folds of that of the eggs from pre-immunized hens 10 days post-immunization. Inhibition of the growth of S. aureus by anti-SpA antibodies purified by SpA-affinity chromatography (PURE-1A) was observed in laying hens vaccinated. Growth of the bacteria in blood agar plates occurred in antibody samples from preimmunized laying hens only. Inhibition of the agglutination of SpA-bearing Staphylococcus aureus cells by purified anti-SpA antibodies was observed in vitro. The authors are not aware of previous studies of the primary immune system response developed in eggs from laying hens, so this research could set a precedent in the field of egg white immunoglobulin technology. The use of hyper-immune eggs as alternative to the use of antibiotics could be advantageous for the large amount of antibodies produced, low cost, the reduction of antigenic variation and very low toxicity.