Atividade bactericida e inibição da formação de biofilmes de Staphylococcus aureus pelo vidro bioativo F18

Abstract

The number of surgeries for implants placement and prostheses that are performed annually in the world have been growing exponentially, together with concerns about infections that can affect patients in the postoperative period. In this context, the bactericidal properties of bioactive glasses have been widely studied. F18 is a new bioacitive glass developed at the Vitreous Materials Laboratory of the Department of Materials Engineering of the Federal University of São Carlos (LaMaV-DEMa/UFSCar), which presents the possibility of manipulation in different formats, such as powder, and can be used in the coating of implants and in direct applications in the skin, aiding in the healing of wounds. The objectives of this study were to evaluate the in vitro antibiofilm and bactericidal activity of F18 biofilms of Staphylococcus aureus and bactericidal activity in biofilms of methicillin-resistant Staphylococcus aureus (MRSA). For this purpose, the ability to inhibit the growth of the biofilm by F18 was verified, maintaining a direct contact between the bacterial inoculum and the biomaterial. In addition, the bactericidal activity of the dissolution products of F18 and of the powder was investigated by means of direct application, at concentrations of 50 mg/mL, 25 mg /mL, 12,5 mg/mL, 6,25 mg/mL and 3,12 mg/mL. Finally, the influence of pH on the bactericidal activity was analyzed. It was observed that F18 presented antibiofilm activity after 12 hours of direct contact between the inoculum of S. aureus and the biomaterial reducing in more than 6 logs the viable bacterial population. In addition, F18 presented bactericidal activity in a preformed biofilms of S. aureus and MRSA, reducing more than 6 logs of viable bacterial cells after 24 hours of contact with 50mg/mL in the two forms of application tested. It was noted that pH neutralization is directly related to the decrease in bactericidal efficacy of F18. The results extended the possibility of using the F18 bioactive glass due to its effectiveness in the antibiofilm and bactericidal activity under the conditions tested. In the future, it may result in its use as an aid in the treatment of infections.