Effects of bone cement loaded with teicoplanin, N-acetylcysteine or their combination on Staphylococcus aureus biofilm formation: an in vitro study

Abstract

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 degrees 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 10(5)+/- 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.