亚抑菌浓度庆大霉素对铜绿假单胞菌的影响

Effet of sub-minimal inhibitory concentration of Gentamycin on

摘要:

：目的探讨亚抑菌浓度庆大霉素（GEN）对铜绿假单胞菌（PAO1）浮游菌和生物膜的影响。方法采用 微量肉汤稀释法检测PAO1对GEN的敏感性。采用96 孔板比浊法检测亚抑菌浓度GEN对PAO1浮游菌生长 的影响，并通过结晶紫染色法检测亚抑菌浓度GEN对PAO1生物膜形成的影响。采用化学反应比色法测定亚抑 菌浓度GEN 对PAO1 毒力因子表达的影响。结果GEN 对PAO1 的最低抑菌浓度为2 μg/ml；而当GEN浓 度≤0.250μg/ml时，不影响PAO1 浮游菌的增殖；当GEN为0.125μg/ml时，能促进PAO1生物膜的形成（ < 0.05），且在一定范围内（0.125～0.250 μg/ml）随着GEN 浓度增高，其促进生物膜形成的能力越强；0.125 和 0.250 μg/ml GEN 能促进群体密度信号系统相关基因I、、I、、、和毒力因子青脓素、弹性 蛋白酶、碱性蛋白酶的表达（ <0.05），且呈一定的剂量依赖性。结论亚抑菌浓度GEN 在一定浓度范围内能 促进PAO1 生物膜的形成，并进一步促进群体密度信号系统相关基因和毒力因子的表达。

Abstract:

Objective To study the effect of Gentamycin of sub-minimal inhibitory concentration (sub-MIC) on . Methods Microdilution method was used to detect the sensitivity of to Gentamycin. And the turbidity method was used to check the effect of sub-MIC of Gentamycin on the growth of planktonic bacteria. Then, crystal violet method was used to explore the effect of sub-MIC Gentamycin on the biofilm formation of . Finally, chemical colorimetric method was utilized to test the effect of sub-MIC Gentamycin on the virulence factor production of . Results The MIC of Gentamycin on was 2 滋g/ml. Gentamycin 臆0.250 滋g/ml had no influence on the growth of planktonic bacteria. Gentamycin could significantly enhance the biofilm formation at the concentration of 0.125-0.250 滋g/ml and in a dose-dependent manner ( < 0.05). At the same time, 0.125 and 0.250 滋g/ml Gentamycin could significantly promote the expressions of the quorum sensing system (QS) related genes , , , , and , and the virulence factors pyocyanin, elastase and alkaline protease in a dose-dependent manner ( < 0.05). Conclusions sub-MIC Gentamycin could enhance the biofilm formation and the expressions of QS related genes and virulence factors.