抗菌肽天蚕素B对铜绿假单胞菌感染小鼠创面的抗菌作用

目的观察抗菌肽天蚕素B对小鼠铜绿假单胞菌感染创面的抗菌效果。方法于30只ICR小鼠背部切除全层皮肤(创面为1 cm×1 cm),将铜绿假单胞菌菌液涂抹于创面制成感染模型,并随机分为对照组、磺胺米隆组、抗菌肽组,伤后3 h分别用含等渗盐水、100 g／L磺胺米隆溶液、1g／L天蚕素B的纱布湿敷,每组10只。伤后1～4 d对各组小鼠创面行大体观察;伤前和伤后4 d测量体温,抽取血液观察白细胞变化;伤后4 d检测痂下肌肉组织细菌定量和观察存活情况。结果对照组创面分泌物多、创面潮湿;磺胺米隆组、抗菌肽组创面结痂、干燥、无明显分泌物。各组小鼠术后体温多数上升、白细胞计数均减少。抗菌肽组痂下肌肉组织细菌定量为(42±50)集落形成单位(CFU)／g,明显少于磺胺米隆组(886±804)CFU／g(P<0．05),两组均明显低于对照组(41±28)×105CFU／g(P<0．01)。对照组小鼠伤后4 d存活数明显少于抗菌肽组、磺胺米隆组(P<0．05)。结论天蚕素B对ICR小鼠铜绿假单胞菌感染创面有明显的抗感染作用,可明显降低其死亡率。

The antibacterial effect of cecropin B on Pseudomonas aeruginosa infection of wounds in mice

OBJECTIVE: To investigate the antibacterial effect of a particular antimicrobial peptide Cecropin B(CB) on Pseudomonas aeruginosa infection of wound in mice. METHODS: Thirty ICR mice were enrolled in the study, and the Pseudomonas aeruginosa infection model was reproduced by excision of the full layer of dorsal skin with an area of 1 cm x 1 cm. Then they were randomly divided into C ( control, n = 10, with wet compress of isotonic saline at 3 postinjury hour( PIH) ) , M (with hydropathic compress of 100 g/L mafenide at 3 PIH), A (with wet compress of 1 000 mg/L Cecropin B at 3 PIH) groups. The changes in body temperature and hemogram in each group were determined before and 4 days after injury. Quantitative examination were used to detect the quantity of bacteria in muscular tissue of the wounds, and the survival of the mice were observed on 4 post-injury day( PID). RESULTS: The wounds were moist with more exudation in C group,while that in other groups were dry without obvious exudation. The body temperature of the majority of the mice in each group were elevated, but the number of leucocytes in each group was lowered after operation. The quantity of bacteria in muscle in A group[ (42 +/- 50) CFU/g] was obviously lower than that in M group [(886+/-804) CFU/g, P <0.05] , and it was all obviously lower than that in C group[ (41 +/-28) x 10(5) CFU/g, P <0.01]. The number of surviving mice after 4 PID in C group was evidently smaller than that in A and M groups( P <0. 05). CONCLUSION: The cecropin B possesses obvious anti-bacterial effect on the Pseudomonas Aeruginasa infected wounds of ICR mice, and it can reduce the mortality.