Study on Preparation and Characteristics of Chicken Egg Yolk Immunoglobulin against β-hemolyticus Streptococcus

摘要

Passive immunization using pathogen-specific antigen is a potential method for preparation of specific antibody, which is significant to diagnosis and prevention of diseases. The objective of this study is to prepare and identify egg yolk immunoglobulin (IgY) against fi-hemolyticus streptococcus for diagnosis and prevention of diseases caused by fihemolytic streptococcus. Specific IgY was prepared by hens immunized with fi-hemolytic streptococcus and was extracted from the yolks of eggs by polyethylene glycol two-step precipitation method. The purity and the content of IgY were tested by sodium dodecyl sulfate-polyacrylamine gel electrophoresis (SDS-PAGE) and Bradford method, the activities of IgY were evaluated by Enzyme-linked immunosorbent assay (ELISA), bacteriostatic test and agar gel diffusion test. The purity of IgY could reach 95% with a yield of 108 mg of IgY per egg in the study. And the titer was 1:5120, which could remain for 50 days. According to the agar diffusion test and bacteriostatic test, IgY could combine with fi-hemolytic streptococcus specifically and inhibit the growth of fi-hemolyticus streptococcus in vitro. The current work suggested that this specific IgY was potential as a therapeutic treatment for diagnosis and prevention of diseases caused by fi-hemolytic streptococcus.