Effects of bone cement loaded with teicoplanin, N-acetylcysteine or their combination on Staphylococcus aureus biofilm formation: an in vitro study
Hasan Göçer1, Dilek Emir2, Mehmet Emin Önger3, Nevzat Dabak1
1Department of Orthopedics and Traumatology, Medical Faculty of Ondokuz Mayıs University, Samsun, Turkey
2Department of Medical Microbiology, Medical Faculty of Ondokuz Mayıs University, Samsun, Turkey
3Department of Histology and Embryology, Medical Faculty of Ondokuz Mayıs University, Samsun, Turkey
Keywords: Biofilm; bone cement; N-acetylcysteine; periprosthetic joint infection; Staphylococcus aureus; teicoplanin.
Objectives: This study aims to demonstrate the antibiofilm effects of teicoplanin alone, N-acetyl cysteine (NAC) alone, or combination of both compounds when mixed with bone cement. Materials and methods: A total of four groups were formed by using six cement samples in each, prepared with bone cement having different contents in each group. Group 1 (control group): cement alone without any drugs added. Group 2: 40 g cement, 400 mg teicoplanin. Group 3: 40 g cement, 6 g NAC. Group 4: 40 g cement, 6 g NAC, 400 mg teicoplanin. All cement samples were infected with Staphylococcus aureus for 48 hours at 36.5 °C. Bacterial colonies were then counted by serial dilution method. Bacteria were counted using scanning electron microscopic (SEM) images.
Results: Counts of bacteria colonies were 5.83±1.60 [mean colony forming unit (cfu) x 105±standard deviation (SD)] in group 1, 0.12±0.56 in group 2, 0.11±0.65 in group 3, and 0.01±0.001 in group 4. Significant difference was found between group 1 and all other groups (p<0.05), and between group 4 and all other groups (p<0.05). According to SEM analysis, counts of bacteria (mean±SD) were 1.88±0.45, 0.75±0.26, 0.21±0.22, and 0.13±0.25 in groups 1, 2, 3, and 4, respectively. Significant difference was found between group 1 and all other groups (p<0.05), and between group 4 and all other groups (p<0.05).
Conclusion: N-acetyl cysteine, teicoplanin, and their combination significantly reduced formation of biofilm compared to the control group. Also, combination of NAC and teicoplanin had the highest antibiofilm effect.