兔防御素对耐药绿脓杆菌的抗菌活性及机制研究  

in vitro Antimicrobial Activity of Defensins from Rabbit Neutrophils Against Pseudomonas Aeruginosa and Its Multiple-drug-resistance Strains

作　　者：赵伟业[1] 董碧蓉[1] 周焱[1] 

机构地区：[1]四川大学华西医院老年科,成都610041

出　　处：《四川大学学报（医学版）》2005年第1期83-85,共3页Journal of Sichuan University(Medical Sciences)

摘　　要：目的　探讨兔中性粒细胞防御素对绿脓杆菌耐药株的抗菌活性及其作用机制。方法　用柠檬酸抽提法 ,从家兔中性粒细胞溶酶体中提出防御素粗制品 ,经酸性尿素聚丙烯酰胺凝胶电泳 (AU- PAGE)分离纯化。体外采用微量琼脂糖扩散实验 ,观察兔中性粒细胞防御素 NP2 对绿脓杆菌 ATCC2 785 3及其多重耐药株的抗菌活性 ,透射电镜观察防御素作用后绿脓杆菌各株超微结构的变化。结果　采用柠檬酸抽提法和酸性尿素聚丙烯酰胺凝胶电泳成功地分离纯化出兔中性粒细胞防御素 NP2 。 NP2 对绿脓杆菌 ATCC2 785 3及其多重耐药株有明显的抗菌活性 ,抗菌活性随防御素浓度升高而增强。透射电镜观察显示 ,防御素作用后的菌株细胞膜不连续 ,胞内成分固缩 ,伴空泡形成 ,胞间有大量漏出物。结论　家兔中性粒细胞防御素 NP2 对绿脓杆菌多重耐药株具有杀菌活性。Objective To investigate the role and mechanism of defensins from rabbit neutrophils against the multi-drug-resistant (MDR) strains of Pseudomonas aeruginosa. Methods Defensins were extracted from rabbit peritoneal neutrophil granules with citric acid and purified by acid urea polyacrylamide gel electrophoresis(AU-PAGE). An agrose gel radial diffusion assay for bactericidal activity in vitro was used and ultrastructural changes of the killed Pseudomonas aeruginosa were examined by use of transmission electron microscope. Results NP 2 was isolated and puried successfully by AU-PAGE. NP 2 demonstrated concentration-dependent killing of Pseudomonas aeruginosa and its MDR strain. When the two kinds of Pseudomonas aeruginosa cells exposed to NP 2 were examined by transmission electron microscope, we found that the cell membrane was incomplete, the components of cells condensed into pyknotic bodies accompanied by vacuolization, and there was some transudate between the cells. Conclusion Defensin from the rabbit neutrophils exerts potent bactericidal activity against the MDR strain of Pseudomonas aeruginosa. The findings under electron microscope suggest the theory that defensins are capable of destabilizing the cell membrane permeability and causing the death of microorganism.

关 键 词：防御素 中性粒细胞 绿脓杆菌 多重耐药株 

分 类 号：R392[医药卫生—免疫学]