绿原酸对铜绿假单胞菌生物膜干预作用的体外研究

Intervention of Chlorogenic Acid on Pseudomonas aeruginosa Biofilm in vitro

目的研究绿原酸(chlorogenic acid)在体外抑制铜绿假单胞菌(PAE)生物膜(BF)形成的作用;对早期、成熟BF的破坏及其与头孢他啶(CAZ)的协同杀菌作用。方法构建体外PAO1生物膜模型;2倍稀释法测定最低抑菌浓度(MIC);扫描电镜(SEM)观察载体表面BF形态;连续稀释法行活菌计数。结果24 h载体表面PAE黏附量,绿原酸组少于红霉素(ERY)组和空白对照组(P<0.05);SEM观察绿原酸组和ERY组仅见少量散在的游离细菌,而空白对照组可见大量分布均匀的微菌落和游离细菌;建模3 d,SEM观察绿原酸组仅偶见聚集的细菌,菌体间有少量稀薄的黏液样物质,BF规模小于ERY组和空白对照组,建模7 d SEM观察绿原酸组仅见稀少的薄层BF;绿原酸组载体表面活菌计数少于空白对照组和ERY组(P<0.05);对于早期和成熟BF内PAE,绿原酸+CAZ组,载体表面PAE数量明显少于各对照组(P<0.05)。结论绿原酸可以抑制PAE的BF形成,并对早期和成熟BF具有破坏作用,对于BF内PAE与CAZ有协同杀菌作用,并且强于ERY组。

OBJECTIVE To investigate the effect of chlorogenic acid alone and in combination with ceftazidime （CAZ）on Pseudomonas aeruginosa （PAE） biofilm in vitro. METHODS PAO1 was for biofilm formation in vitro. Biofilm was observed by scanning electron mieroscope（SEM）. Viable bacterial counts were determined by serial dilution. Minimal inhibitory concentration was measured by double dilution. RESULTS Biofilm and viable bacterial counts of PAE adhered to the surface of catheter in chlorogenic acid group were less to the control after cultivated 24 h and 7 d（P〈0. 05）. At the third day, there were small quantity accumulative bacteria in chlorogenic acid group, among them was mucus. The chlorogenic acid could destroy early and mature biofilm. The viable bacterial counts of PAE in chlorogenic acid combined with CAZ group decreased evidently in 3 d and 7 d（P〈0. 05）. CONCLUSIONS Chlorogenic acid can restrain PAE from forming biofilm in vitro. Combined with CAZ, it can also destroy the biofilm of PAE and enhance the effect of CAZ on PAE within the biofilm.