Antibacterial Activity Of Iodophor Against Staphylococus Aureus Biofilm On Surface Of Titanium Plate.An In Vitro Study

【Objective】1、To observe the antibacterial activity of iodophor against the planktonic state of Staphylococcus aureus. 2、To establish a 24 hours old Staphylococus aureus biofilm model on surface of titanium plate in vitro,and observe the structure of the biofilm by confocal laser scanning microscopy(CLSM) and scanning electron microscopy(SEM). 3、To observe the antibacterial activity of iodophor against Staphylococus aureus biofilm on surface of titanium plate,and provide treatment reference for the implant related infections. 【Methods】1、The suspension quantitative germicidal tests were carried out to observe the antibacterial activity of iodophor against the planktonic state of Staphylococcus aureus. 2、Staphylococus aureus was used to establish a 24 hours biofilm on the surfaces of titanium plate and was detected by the confocal laser scanning microscopy and scanning electron microscopy. 3、The clinical used iodophor was diluted in different concentration for experiment useage. The biofilm model was immersed in the iodophor for 5 min.After washing, ultrasound, vortex and so on, Colony forming unit(CFU) assays were performed to quantifying the viable bactertia in the biofilm.4、Use the 0.5% iodophor to treat the biofilm for 10 min,and the same CFU assays as above was performed. 【Results】1. In laboratory conditions, all planktonic Staphylococcus aureus could be killed in 30 seconds with 0.1%、0.2%、0.3%、0.4% and 0.5%iodophor(available iodine concentration). 2. After double fluorescent dye, large number of biofilm structure was detected by CLSM. Bacterium were aggregated into clumps or patchy.The viable bacteria overlapped with dead one, and made them show as yellow patches. Three-dimensional structure showed that the biofilm had certain thickness, the bacteria were gathered as clumps, the viable bacteria and the dead bacteria wrapped with each other. The SEM showed that the bacteria were wrapped with slime-like substance to form a thick cloud-like biofilm. 3. After immersed by iodophor for 5min,0.1%iodophor(available iodine concentration) was able to kill certain amount of bacteria in the biofilm. 0.3%iodophor or higher concentrations were able to reduce the bacteria load in the biofilm to a great extent.After immersed by 0.5%iodophor for 5min,most of the bacteria in the biofilm were killed,but not all of them.Extending the immersing time to 10 min,the CFU became zero. 【Conclusions】The iodophor has antibacterial activity against not only the planktonic state of Staphylococcus aureus,but also the 24 hours old Staphylococus aureus biofilm in vitro.And the antibacterial activity increased as the iodophor concentration increased. 0.3% iodophor or higher concentrations can reduce the bacteria load in the biofilm to a great extent. 0.5% iodophor can kill most of the bacteria in the biofilm but can not eliminate all of them.However extended to 10 min can kill all of the bacteria within the biofilm.