鱼腥草素钠对铜绿假单胞菌黏附的清除作用及对生物被膜形成的影响

目的:研究鱼腥草素钠(houttuyfonate sodium,SH)对铜绿假单胞菌(Pseudomonas aeruginosa,Pa)黏附的清除作用及对生物被膜(biofilm,BF)形成的影响。方法:用96孔板孔建立铜绿假单胞菌黏附生物被膜,MTT法检测膜内菌的代谢变化、评价药物对黏附菌的最小清除浓度(minimum eliminateing concentration,MEC)及最小抑膜浓度(sessile minimal inhibitoryconcentration,SMIC);菌落计数法观察药物对黏附、膜内菌量影响;扫描电镜观察药物对受试菌黏附作用及生物被膜的形态结构影响。结果:鱼腥草素钠对铜绿假单胞菌的MEC80为500 mg·L-1,MEC50为125 mg·L-1,对铜绿假单胞菌早期生物被膜和成熟生物被膜SMIC80均为500 mg·L-1,早期生物被膜、成熟生物被膜SMIC50分别为31.25,1.95 mg·L-1。250 mg·L-1药物浓度使载体上黏附的及初步生物被膜、成熟生物被膜内的活菌数明显减少,和对照组比较差异显著(P<0.05),扫描电镜观察黏附载体上的细菌明显减少,连续用药后,成熟生物被膜阶段载体上未见有生物被膜结构,菌量明显减少并且细菌形态发生变异,由杆状变为球杆状。结论:鱼腥草素钠对铜绿假单胞菌的黏附有较强的清除活性,通过连续给药能抑制铜绿假单胞菌生物被膜的形成。

Effects of houttuyfonate sodium on eliminating adhesion of Psedomonas aeruginosa and forming biofilms

Objective: To investigate the effect of houttuyfonate sodium (HS) on eliminating adhesion of Psedomonas aeruginosa(Pa) and forming biofilms.Method: Pa biofilms were established in 96-hold plates. MTT assay was used to evaluate the changes in metabolism of biofilms and assess the minimum eliminating concentration and minimum biofilm inhibitory concentration for adherent Pa. The colony counting method was used to observe the effect of HS on Pa adhesion and biomass in biofilms. SEM was employed to examine the effect of HS on adhesion of tested Pa and morphology of biofilms.Result: MEC₈₀ and MEC₅₀ of HS for adherent Pa was 500 mg·L^-1 and 125 mg·L^-1, respectively. Meanwhile, its SMIC₈₀ for either early or mature biofilms of Pa was 500 mg·L^-1, and SMIC₅₀ for early and mature biofilms of Pa were 31.25, 1.95 mg·L^-1, respectively. At the concentration of 250 mg·L^-1, the number of viable bacteria in the state of adhesion and in initial and mature biofilms decreased significantly, compared with the control group (P<0.05). The number of bacteria on adherent carriers notably reduced under SEM. Following the continuous administration, there were no visible biofilms on carriers in the mature biofilm phase, with the biomass remarkably shrinking and the bacterial morphology changing from bacillus into coccobacillus.Conclusion: HS displayed powerful effect on eliminating adherent Pa, and can inhibit Pa biofilm from being formed through continuous administration.