The Research Of Enterococcus Faecalis Biofilm Formation And Drug Effects

Objective: In this work we use the Atomic Force Microscopy(AFM) observ the surface of Enterococcus Faecalis and the dynamic forming process of Enterococcus Faecalis biofilms at air condition.The focus of a comparative study of two kind of antimicrobial agents about sodium hy- pochlorite and teicoplanin to the Enterococcus Faecalis biofilms sensitivity.Methods:Experitment one: Use the Atomic Force Microscopy observe the surface of Enterococcus Faecalisr at air condition and in2-Ddisplay.Experitment two:In vitro we use the cellulose nitrate film to construct the Enterococcus Faecalis biofilms model,and then place the biofilms under the AFM to observe the surface changes of biofilms development. MTT me- thod was used to test the bioactivity of Enterococcus Faecalis biofilms.Experiment three:We first uses two time of dilution method deter- minations to determine the sodium hypochlorite and teicoplanin against Enterococcus faecalis in minimal inhibitory concentration (MIC) and mini- mum bactericidal concentration (MBC).In vitro construct the mature Enterococcus Faecalis biofilms model , plus different concentrations of sodium hypochlorite and teicoplanin to determine the number of viable and judge teicoplanin and sodium hypochlorite on Enterococcus faecalis biofilm inhibition.Results: Experitment one: AFM can image morphology of Entero- coccus Faecalis 2-Ddisplay.The cell surfaces of strain Enterococcus Fae- calis were not regular because of the presence ofthe amorphous substance on the colony surface.Experitment two: Gradually determine that at 6 hours the initial biofilm formed and at 24 hours the biofilms maintained the steady-state. AFM height images showed topographical changes due to biofilm deve- lopment, which were used to characterize several aspects of the bacterial surface, such as the presence of extracellular polymeric substance, and the biofilm development stage.Experitment three: sodium hypochlorite to the Enterococcus Faecalis smallest bacteriostasis density (MIC) and the smallest sterilization density (MBC) respectively be 0.625%,1.25% and teicoplanin to the Enterococcus Faecalis smallest bacteriostasis density (MIC) and the smallest sterilization density (MBC) respectively be 1ug/ml,4ug/ml. 2MIC ~ 10MIC of sodium hypochlorite and teicoplanin both can inhibit Enterococcus faecalis biofilm.Conclusion:1. Application of atomic force microscopy can observe the surface of Enterococcus faecalis.2.The experiment had initially determined the biofilms basically for- med the time is 6h, the mature time was 24 h, the structure is more stable after the formation3. The biomembrane state excrement intestinescoccus compared to floats the fungus to have the formidable antibiotic nature.