Studies On Isolation, Purification And Antibacterial And Antivirus Activity Of Ostrich Neutrophil Antimicrobial Peptides

Fresh anticoagulant blood was connected and reated with 0.83% ammonium Chioride to yse the red blood cells whereas keep the leukocytes intact.Then the white blood cellswere dismpted by sonication and centrifugated.Pellets were resuspended in 10% acetic acid and stirred to extract peptides , followed by centrifogation and freeze-drying.The crude extract was collected andtresuspended in 0.0l% acetic acid.Antimicrobial activity was checked and the results showed that there natural antimicrobial substances in strich blood neutrophil.The crude extrac twas run by ion-exange chromatography to separate the anioonic and cationic fractions,and the latter showed antimicrobial activities.RP-HPLC method was The results of SDS一PAGE showed that the molecular weights of the active peaks was 4700-4980Da .Use the radial diffusion plate assay method, the crude extracts'antimicrobial activity against Escherichia.coli O78, Staphylococcus.aureus 1056MRSA and Candida.albicans ATCC10231 were revealed. The results showed that there were antimicrobial matters in ostrich neutrophil, and there were strongly active against all the bacteria strains above.Use the radial diffusion plate assay method, the iox-exchange chromatography fractions'antimicrobial activity against Escherichia.coli O78, Staphylococcus.aureus 1056MRSA and Candida.albicans ATCC10231 were revealed. The results showed that ostrich neutrophil antimicrobial peptides were cationic molecules. Different to other animals the avian cationic antimicrobial peptides were active against the bacteria, especially the Staphylococcus.aureus 1056MRSA, and the antimicrobial activity of the iox-exchange chromatography fractions against the Candida.albicans ATCC10231 were stronger than that against Escherichia.coli O78. Use the radial diffusion plate assay method, the reversed phase high performance liquid chromatography (RP-HPLC) fractions'antimicrobial activity against Escherichia.coli O78, Staphylococcus.aureus 1056MRSA and Candida.albicans ATCC10231 were revealed. The results showed that Compared with the reported ostrich neutrophil antimicrobial peptides, the peptides of our research obtained have stronger activity. Treated the Newcastle disease virus(NDV) and Infectious bronchitis virus(IBV) with ABP, then inoculate them into chicken'embryo ,then measured the erythrocyte agglutination titer of NDV in chicken embryo allantoic fluids, and observe the pathological changes of chicken embryo. The result showed that the erythrocyte agglutination titer of NDV was lower than controlled series, and the pathological changes were less serious than controlled series, indicate that ABP can inhibit the pathological changes of chicken embryo caused by NDV and IBV.