家蝇消化腺抗菌肽生物活性的研究

Study on the biological activity of antibacterial peptides from digestive glands of houseflies

目的研究家蝇消化腺抗菌肽抗菌活性和细胞毒性。方法针刺细菌感染法诱导家蝇幼虫表达抗菌肽,采用显微解剖的方法解剖并收集成蝇中肠,用超声破壁低温离心等技术提取、纯化抗菌肽,用提取的抗菌肽进行抑菌试验及细胞毒性试验。结果金黄葡萄球菌诱导的家蝇中肠抗菌肽抑菌环直径为1.3 cm,正常成蝇中肠抗菌肽抑菌环直径为1.1 cm,青霉素及蛆血淋巴抗菌肽抑菌环直径分别为1.0和<0.5 cm。细胞毒性试验中,各浓度抗菌肽组细胞生长正常。讨论中肠抗菌肽抑菌活性优于蝇蛆血淋巴抗菌肽的抑菌活性,且细胞毒性低。

Objective To investigate the antimicrobial activity and cytotoxicity of antibacterial peptides from digestive glands of houseflies.Methods Housefly larvae were inoculated with bacterium to induce antibacterial peptides.The midgut of houseflies was collected and microdissected.Antibacterial peptides were extracted and purified from the midgut by ultrasound and hypothermia centrifugation.The extracted samples were tested for antimicrobial activity and cytotoxicity.Results The inhibition zone produced by antibacterial peptides from the midgut of houseflies infected with Staphylococcus aureus had a diameter of 1.3 cm.The inhibition zone produced by antibacterial peptides from the midgut of normal flies had a diameter of 1.0 cm.The inhibition zone produced by penicillin had a diameter of 1.0 cm and that produced by antibacterial peptides from hemolymph had a diameter of less than 0.5 cm.In cytotoxicity tests,groups of cells with different levels of antibacterial peptides developed normally.Conclusion Antibacterial peptides from the midgut had greater antimicrobial activity than did antibacterial peptides from hemolymph,and antibacterial peptides from the midgut had a low level of cytotoxicity.