Study On Preparation And Characteristics Of Chicken Egg Yolk Immunoglobulin Against Group A β-hemolyticus Streptococcus

β-hemolyticus streptococcus is the main pathogen of streptococcal infection. According to the different specific antigen in the cell wall (polysaccharides) it is divided into A～H, K～T a total of 18 family, and then the group is divided into several serotype according to different surface proteins M, K, T, S. The group caused pathogenicity to human in (3-streptococcus hemolyticus is group A, which has strong pathogenicity, often causes human and animal diseases such as skin, subcutaneous tissue of the suppurative inflammation, respiratory infections, pharyngitis outbreak of epidemic prevalence and neonatal sepsis, bacterial endocarditis, scarlet fever and rheumatic fever, glomerulonephritis, etc. Currently, macrolide antibiotics and (3-lactam antibiotics are mostly used to treat diseases caused by Group A P-streptococcus hemolyticus, But the drug resistance of bacteria are growing. So it is urgent to making the search for a safe and efficient succedaneum of antibiotics.Chiken egg yolk immunoglobulin (IgY) provides an inexpensive and effective source of antibodies for the passive immunization of animals. It is a promising alternative for the treatment and prevention of bacteria infections, and has shown to be effective against a number of pathogens. The objective of this study is to prepare and identify egg yolk immunoglobulin (IgY) against Group Aβ-hemolyticus streptococcus for diagnosis and prevention of diseases caused by (3-hemolytic streptococcus. Specific IgY was prepared by hens immunized withβ-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 92.5% with a yield of 10.8±0.87 mg of IgY per egg in the study. And the titer was 1:5120, which could remain for 30 days. The stability of the Purified specific IgY to heat and PH was studied. The result showed that the IgY stable at pH 4～9 and below 75℃and have high specificity. According to the agar diffusion test and bacteriostatic test, IgY could combine with Group Aβ-hemolytic streptococcus specifically and inhibit the growth of P-hemolyticus streptococcus in vitro when antibody concentration was greater than 10 mg/mL. The minimum inhibitory concentration (MIC) was 25 mg/mL. The current work suggested that this specific IgY was potential as a therapeutic treatment for diagnosis and prevention of diseases caused by Group Aβ-hemolytic streptococcus.