Adhesion of Staphylococcus aureus to implants with different physicochemical characteristics

Adhesion of pathogenic Staphylococcus aureus (strain 209) to BT1-0 titanium disks (12 mm in diameter) with different coatings and noncoated was studied in vitro by photocolorimetry. Transparency of bacterial suspension in normal saline was evaluated after 2-h culturing with the implants at 37°C. The decrease of S. aureus content in the suspension due to its adsorption on implants was negligible and increased by 0.9-5.5% in comparison with the control (adhesion to glass). When the specimens were placed into bacterial suspension, the density of staphylococcal adsorption on the surface considerably increased (by 9-53%) in comparison with the control, which attested to active participation of the implants in bacterial adsorption. The degree of bacterial adhesion to the implants decreased in the following order: disk with calcium phosphate ceramic coating - disk with calcium phosphate X-ray amorphous coating - disk without coating - disk with cermet coating. The adhesion of Staphylococcus is a stochastic process depending on the sum of implant characteristics, in particular, on the phase composition of the coating, electric conductivity, and Ca/P ionic ratio. The authors conclude that the formation of antibacterial properties of coating by saturating them with antibiotics or impregnation with metals, specifically silver ion implantation, is justified, because it reduces the postimplantation infection risk.