地榆对MRSA生物被膜形成的抑制作用

Inhibitory effects of Sanguisorba officinalis L. on MRSA biofilms formation

目的研究地榆对MRSA41577菌株生物被膜(bacterial biofilm,BF)的抑制作用。方法采用刚果红法和结晶紫半定量法检测供试菌株BF的形成能力;采用氯化三苯基四氮唑(TTC)法测定地榆对MRSA41577BF形成和成熟BF的抑制作用,以及地榆与万古霉素联用对MRSA41577成熟BF的抑制作用。结果地榆对MRSA41577BF形成和成熟BF有显著的抑制作用,其抑制MRSA41577BF形成的最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimal bactericidal concentration,MBC)分别为1 mg/m L和8 mg/m L。抑制MRSA41577成熟BF的MIC为4 mg/m L。当用亚抑菌浓度的地榆与万古霉素联合作用后,可显著提高成熟BF对万古霉素的敏感性。万古霉素的浓度≤64μg/m L时,对MRSA41577成熟BF没有破坏作用,当1/4MIC的地榆与4μg/m L万古霉素联用,即可对供试菌株成熟BF有抑制作用。结论地榆对MRSA41577BF形成有显著的抑制作用,其作用机制与地榆破坏BF结构,使万古霉素等抗生素渗透到BF内来完成杀菌作用有关。

Objective To investigate inhibitory effects of Sanguisorba officinalis L. on biofilms of MRSA41577. Methods Congo red agar method and crystal violet semi-quantitative method were used to detect the biofilms-forming ability of tested strains; TTC assay was used to detect inhibitory effects of Sanguisorba officinalis L. on biofilms formation and mature biofilms of MRSA41577,as well as effects of Sanguisorba officinalis L. in combination with vancomycin on mature biofilms of MRSA41577. Results Sanguisorba officinalis L. showed significant inhibitory both on biofilms formation and mature biofilms,minimum inhibitory concentration（MIC） and minimal bactericidal concentration（MBC） of biofilms formation were 1 mg/m L and 8 mg/m L,MIC of mature biofilms was 4 mg/m L. The sensitivity of mature biofilms to vancomycin was greatly increased when Sanguisorba officinalis L. was combined with vancomycin with subinhibitory concentrations. Sanguisorba officinalis L. at 1/4 MIC can inhibit mature biofilms when combined with vancomycin at 4 μg/m L, while vancomycin didn＇t show inhibitory effects on mature biofilms when concentrations were below 64 μg/m L.Conclusion Sanguisorba officinalis L. has significant inhibitory on biofilms formation, the mechanism may be related to Sanguisorba officinalis L. destroyed biofilms and make vancomycin penetrate into the biofilms to finish the bactericidal activity.