Research on the effect of TiO2 nanotubes coated by gallium nitrate on Staphylococcus aureus-Escherichia coli biofilm formation

Abstract

Background: In clinical practice, the cases with bacterial infection caused by titanium implants and bacterial biofilm formation on the surface of titanium materials implanted into human body can often be observed. Thus, this study aimed to demonstrate whether the mixed biofilm of Staphylococcus aureus/Escherichia coli can be formed on the surface of titanium material through in vitro experiments and its formation rules. Methods: The titanium plates were put into the well containing S aureus or/and E coli. Bacterial adhesion and biofilm formation were analyzed by crystal violet, XTT method, confocal laser scanning microscopy, and scanning electron microscopy. Results: The results of bacterial adhesion in each group at 6-72 hours showed that the number of bacterial adhesion in each group was increased with the extension of time and reached to the highest level at 72 hours. Moreover, the biofilm structure in the S aureus-E coli group was significantly more complex than that of the simple S aureus group or E coli group, and the number of bacteria was also significantly increased in the S aureus-E coli group. Conclusion: Those data provide a laboratory basis for the prevention and treatment of mixed infection of subsequent biological materials.