Introduction: Infections caused by Staphylococcus epidermidis form frequent complications after implantation of foreign bodies, including orthopedic implants. The ability of adhesion to synthetic surfaces is influenced by both the properties of the microorganisms under concern as well as physicochemical properties of the implant surface. In this study, biofilm formation abilities by S. epidermidis strains on orthopedic implants made of different materials have been evaluated.
Methods: Researches have been performed on 60 S. epidermidis strains. The implants for osteosynthesis--cortical bone screws: steel, steel coated with titanium and steel coated with nanocrystalline diamond were used for the analysis. Slime production ability was assessed using Congo Red Agar method. Cell surface hydrophobicity was determined by salt aggregation test (SAT) and bacterial adhesion to hydrocarbon test (BATH). Presence of the icaA, icaD, icaC and icaB genes was detected by PCR. Biofilm formation of S. epidermidis strains was analysed according to Richards method.
Results: Out of the 60 strains 43% were labeled as slime producing. 48% of S. epidermidis strains formed biofilm on steel screws, 43% on titanium implants and 45% of strains on implants coated with nanocristalline diamond. IcaA, icaD, icaC and icaB genes have been detected in 31%, 25%, 20% and 27% of the strains respectively.
Conclusions: The degree of biofilm formation was the lowest on the steel screws coated with titanium.