克拉霉素和头孢他啶对体外腹膜透析管大肠杆菌生物被膜的干预作用

The effects of Clarithromycin and Ceftazidime on the biofilm of Escherichia coli in peritoneal dialysis catheter in vitro

目的通过在腹膜透析管(简称腹透管)上建立大肠杆菌(Escherichia coli,E.coli)生物被膜(bio-film,BF)模型,探讨克拉霉素和头孢他啶对腹透管E.coli BF的体外影响。方法按透析后无菌腹透液-腹透管系统建立体外E.coli BF模型。用试管二倍稀释法测定药物的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结晶紫染色法观察克拉霉素对E.coli形成BF的干预作用。1/4 MIC克拉霉素、1 MBC头孢他啶单独和联合作用(1/4MIC克拉霉素+1MBC头孢他啶)成熟BF后,以连续稀释法、结晶紫染色半定量法和扫描电镜(SEM)观察药物作用后BF的变化。结果腹透管上成功建立E.coli BF,1 d形成早期BF,7 d形成成熟BF。与对照组比较克拉霉素干预E.coli形成BF于1、3、7 d的酶标值均降低(P<0.05)。克拉霉素组、头孢他啶组、克拉霉素+头孢他啶组(联合组)与对照组比较,BF内活菌数和BF酶标值均减少,且联合组减少更显著(P<0.01)。SEM观察到联合组对成熟BF破坏更明显。结论本实验在腹透管上成功建立E.coli BF模型。克拉霉素可减少E.coli对腹透管的黏附和抑制E.coli BF的形成,且与头孢他啶联合对腹透管E.coli BF呈抗菌协同作用。

Objective To investigate the effects of Clarithromycin and Ceflazidime on the biofilm （BF） of Esche- richia coli （ E. coli） in peritoneal dialysis catheter in vitro. Methods The E. coli BF model was established using the per- itoneal dialysis solution and catheter. The minimal inhibitory concentration （ MIC ） and minimum bactericidal concentration （MBC） of Clarithromycin and Ceftazidime against E. coli were determined by tube broth dilution method. Crystal violet staining was used to evaluate the effect of Clarithromycin on the formation of E. coli BF. The matured BF was treated by Clarithromycin, Ceftazidime and their combination; and subsequently evaluated with serial dilutions, crystal violet staining and scanning electronic microscope （SEM）. Results The peritoneal dialysis catheter BF was successfully established, with early and matured BF observed on the 1 st and 7th day, respectively. The Clarithromycin intervention significantly re- duced the formation of E. coli BF, representing with reduction in enzyme production on the 1st, 3rd and 7th day （P 〈 O. 05 ）. The viable bacteria count and enzyme production were significantly reduced with the treatment of Clarithromycin, Ceflazidime and their combination, among which the it was significantly the most prominent in combination treatment group （P 〈 0. 01 ）. It was also demonstrated by SEM that the combination treatment could significantly damage E. coli BF. Con- clusion E. coil BF is successfully established on the surface of peritoneal dialysis catheter. Clarithromycin inhibits the ad- herence of E. coli and the formation of E. coli BF, and enhances the anti - bacterial activity of Ceftazidime against E. coli BF.