罗红霉素与氟罗沙星联合应用对铜绿假单胞菌生物被膜的影响

目的 研究罗红霉素（ＲＸＭ）对铜绿假单胞菌生物被膜（ＢＦ）形成的抑制及其对氟罗沙星（ＦＬＲＸ）杀灭ＢＦ细菌的增效作用。方法 采用改良的平析增减法建立ＢＦ模型，经不同浓度ＲＸＭ和ＦＬＲＸ合用后，进行银染法鉴定、扫描电镜（ＳＥＭ）观察、多糖蛋白复合物（ＧＬＸ）含量测定、噻唑兰试剂盒（ＭＴＴ）法测定ＢＦ存活细菌数。结果 １／１６倍最低抑菌深度（ＭＩＣ）、１／４ＭＩＣ ＲＸＭ可非常显著地抑制ＢＦ多糖蛋白复

Influence of roxithromycin combined with fleroxacin on bacterial biofilm induced by pseudomonas aeruginosa

OBJECTIVE: To investigate the influence of roxithromycin (RXM) on the production of glycocalyx (GLX) and the synergic effect of RXM and fleroxacin (FLRX) on P. Aeruginosa biofilms. METHODS: Bacterial biofilm (BF) was established and was influenced by RXM and FLRX with different concentrations. The samples were detected with scanning electron microscope and by a rapid method after BF was stained with AgNO3 solution. The synergism of antibacterial activities of RXM and FLRX to P. Aeruginosa was studied by computer image analysis and MTT method. RESULTS: GLX production was reduced significantly by both 1/16 MIC and 1/4 MIC RXM (P < 0.01). 1/16 MIC and 1/4 MIC RXM showed no bactericidal activities to P. Aeruginosa in biofilms, while viable counts in biofilms almost had no difference. However, RXM could enhance the bactericidal activity of FLRX to P. Aeruginosa in biofilms. When FLRX of different concentrations was combined with 1/16 MIC and 1/4 MIC RXM respectively, the difference of the stained BF was counted up by computer image analysis system with significance of P < 0.05 and the viable counts were reduced significantly (P < 0.05). The results was in accordance with SEM pictures. CONCLUSION: RXM has no direct bactericidal activities to P. Aeruginosa in biofilms, but it could inhibit GLX production. It can be considered that RXM could enhance antibacterial activities of FLRX by enhancing the permeability of FLRX into biofilms.