中文摘要：

目的研究环丙沙星（CIP）、乳铁蛋白多肽嵌合体（LFchimera）单用及二者联合对铜绿假单胞菌毒力因子生成的影响。方法以铜绿假单胞菌野生菌株PAO1为实验菌株,分为对照组（无任何干预的铜绿假单胞菌野生菌株PAO1）,CIP（0.04μg/mL）组,LFchimera（0.25μmol/L）组,LFchimera（1μmol/L）组,CIP（0.04μg/mL）＋LFchimera（1μmol/L）组,分别测定毒力因子绿脓菌素的浓度（氯仿萃取法）、弹性蛋白酶（弹性蛋白-刚果红法）、胞外蛋白水解酶（偶氮酪蛋白法）。结果和对照组比较,CIP组,LFchimera（0.25μmol/L）组,LFchimera（1μmol/L）组,CIP（0.04μg/mL）联合LFchimera（1μmol/L）组的绿脓菌素浓度下降,弹性蛋白酶和蛋白水解酶活性降低,差异均有统计学意义（均P〈0.05）;CIP组和LFchimera（0.25μmol/L）组比较,绿脓菌素浓度、弹性蛋白酶和蛋白水解酶活性的差异均无统计学意义（均P〉0.05）;LFchimera（1μmol/L）组绿脓菌素浓度、弹性蛋白酶和蛋白水解酶活性较CIP组和LFchimera（0.25μmol/L）组降低,差异均有统计学意义（均P〈0.05）;CIP（0.04μg/mL）联合LFchimera（1μmol/L）组和各单独用药组比较,绿脓菌素浓度下降,弹性蛋白酶和蛋白水解酶活性降低,差异均有统计学意义（均P〈0.05）。结论亚抑菌浓度的CIP和LFchimera都对铜绿假单胞菌毒力因子（绿脓菌素、弹性蛋白酶和蛋白水解酶）的生成有抑制作用,随着LFchime-ra浓度的提高这种抑制作用加强,而CIP联合LFchimera能进一步增强这种抑制作用,说明两者在抗铜绿假单胞菌毒力因子方面有协同作用。

英文摘要：

Objective To investigate the effect of ciprofloxacin（CIP）in combination with lactoferrin-derived peptides chimera（LFchimera）on virulence factors of Pseudomonas aeruginosa（P.aeruginosa）.Methods The wild type strain of P.aeruginosa-PAO1was used as experimental strain.Five groups were established,including control group（the wild type strain of P.aeruginosa-PAO1without any intervention）,CIP group（0.04μg/mL）group,LFchimera（0.25and 1μmol/L） groups,LFchimera（1μmol/L）plus CIP（0.04μg/mL）group.The virulence factors,including pyocyanin,elastase and extracellular proteolytic enzyme,were determined by chloroform extraction method,Elastin-Congo Red method and Azocasein method,respectively.Results The pyocyanin concentration,elastase activity and proteolytic enzyme activity were significantly reduced in the CIP group,0.25μmol/L LFchimera group,1μmol/L LFchimera group and CIP plus LFchimera group compared with those in the control group（P〈0.05）.There was no significant difference in the virulence factors between the CIP group and the 0.25μmol/L LFchimera group（P〈0.05）.Moreover,the level of the virulence factors was substantially reduced in the CIP plus LFchimera group when compared with 1μmol/L LFchimera group and CIP group（P〉0.05）.Conclusion Both CIP and LFchimera at sub-MICs can inhibit the production of virulence factors（such as pyocyanine,elastase and proteolytic enzyme）in Pseudomonas aeruginosa.They have synergistic effect on the resistance of virulence factors in Pseudomonas aeruginosa.