In vitro Effect of Four Kinds of Implant Materials on Biofilm Formation of Staphylococcus epidermidis / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate the in vitro effect of 4 kinds of implant materials on the biofilm formation of Staphylococcus epidermidis.METHODS S.epidermidis was cultured,purified and identified.Susceptibility test was done for S.epidermidis and the ability to produce biofilm was proven.The test samples were made into wafer shape for titanium alloy,Co-Cr-Mo alloy,ultrahigh molecular weight polyethylene(UHMWPE)and home-made polymethyl methacrylate(PMMA).S.epidermidis was cultured with 4 kinds of test samples for 5 days respectively.Bacteria adhering on surfaces of 4 kinds of test samples were dissolved with trypsin,and then diluted into bacterial suspensions.Each bacterial suspension was inoculated quantitatively and CFU were counted.Biofilm on surfaces of 4 kinds of test samples prepared by vacuum drying method was observed with SEM.RESULTS The strain proven to be S.epidermidis,was resistant to semisynthetic penicillins,and could produce biofilm.CFU count showed that CFU were the most on the UHMWPE surface and the number of CFU were(24.96?1.459)?105.CFU were(17.44?1.883)?105 on the PMMP surface.(0.424?0.065)?105 CFU were discovered on the surfaces of titanium alloy and(0.382?0.075)?105 CFU on Co-Cr-Mo alloy.When each group compared with UHMWPE and domestic PMMA respectively,all P value was