家蝇幼虫抗菌肽对阴沟肠杆菌感染小鼠创面的抗菌活性

Antibacterial effect of the antibacterial peptide from housefly larvae on Enterobacter cloacae infected wound in mice

目的:观察抗菌肽对阴沟肠杆菌感染小鼠创面的抗菌作用。方法:超声处理诱导家蝇幼虫产生抗菌肽,经分离纯化后,体外实验分析抗菌肽的抑菌特性。取ICR小鼠30只,切除背部1cm×1cm全层皮肤,涂抹阴沟肠杆菌菌液作为感染模型,随机分为3组。伤后2h和每天各组分别用等渗生理盐水、100g/L的磺胺米隆或0.1g/L抗菌肽滤纸湿敷,伤前和伤后3d抽血观察白细胞变化;伤后3d痂下肌肉组织细菌定量和计算存活率。结果:抗菌肽纯化蛋白对阴沟肠杆菌的抑菌活性较强;术后3组白细胞记数均减少,对照组显著低于其他两组(P<0.05);痂下肌肉组织细菌定量抗菌肽组(99±32)×102CFU/g和磺胺米隆组(87±31)×102CFU/g,均显著低于对照组(504±338)×103CFU/g(P<0.01);对照组伤后3d存活率明显少于其他两组(P<0.05)。结论:超声处理能诱导家蝇幼虫产生抗菌肽,其对阴沟肠杆菌感染的ICR小鼠创面有较强抗感染作用。

Objective： To investigate the antibacterial effects of the antibacterial substances on Enterobacter cloacae infection of wound in mice. Methods： Antibacterial substances of the larvae of housefly were induced by ultrasonic treatment,and its antibacterial activity was investigated with inhibition experiment in vitro. Thirty ICR mice were enrolled in the study, and the Enterobacter cloacae infection model was reproduced by excision of the full layer of dotal skin with an area of 1 cm×1 cm. Then they were randomly divided into group C （ control , n=10 , with wet compress of isotonic saline）,group M（with hydropathic compress of 100 g/L mafenide） and group A（with wet compress of 0.1 g/L antibacterial peptide）.The changes of white blood cell counts in each group were determined before and 3 days after injury. Bacterial growth in muscular tissue of the wounds and the survival of the mice were observed at 3 days after injury. Results： The purified peptide was highly potent against Enterobacter cloacae in vitro. The number of leucocytes in each group was decreased after operation, with significantly less number in group C than in group M and A. Bacterial growth in muscle demonstrated a difference between treated groups and group C at 3 days [group M： （87 ± 31 ） ×10^2 CFU/g; group A： （99 ± 32） × 10^2 CFU/g; group C： （504 ± 338） ×10^3 CFU/g]（P〈O.01 ）.The survival after 3 days in group C （60%） was evidently smaller than that in group A （90%）and M （90%）（P〈0.05）. Conclusion： The antibacterial peptide of housefly which is induced by ultrasonic treatment possesses obvious antiacterial effect on the Enterobacter cloacae infected wounds of ICR mice.