猪小肠抗菌肽的杀菌作用及机理研究

The Bactericidal Activity and Function of the Antibacterial Peptide from Pig Intestine

酸性条件下提取猪小肠上段组织菌肽，测试１１种１３株细菌、病毒原虫的活性，大肠杆菌最敏感。

The antibacterial peptide was isolated from the upper part of a porcine small intestine and antimicrobial activity was tested for 11 species including 13 strains of bacteria,viruses and protozoa. Among them the most sensitive bacterum is Escherichia coh.When the polypeptide was at a concentration of 80μg/ml and E.coli growth was at a level of 2×10~5CFU/ml,100% of the bacteria were inactivated;Killing of 50% E.coli,Pseudomonas aeruginosa,Staphococcus aureus and Salmonella typhi, the dosage of the antibacterial peptide was 1.0,6.4,20 and 32μg/0.8ml,respectively.It has been proved that the antibacteria peptide possess bacteriostasis for resistant strains of S.aureus and S.typhi to 11 antibiotics.Observing the E.coli treated with the antibacteria peptide by TEM,one to several bleb- like structures were often seen on the terminal or subterminal of the bacterial body,the protoplasm flowed out,their electronic density of the organisms reduced,some of the dead bacteria only left wreckage of the cell walls.It is proved that the antibacterial peptide permeabilized the bacterial out- membrane and led to form the pores or voltage-dependent ion-permeable channels.In addition,the medical and pharmacal significance of antibacterial peptide has been discussed.