Antimicrobial Efficacy of Silver-Hydroxyapatite

The antimicrobial activity of the AgHA, AgHA-C, and AgHA-T suspensions and tetracycline and ciprofloxacin were investigated in vitro using the reference Staphylococcus aureus ATCC 25923 (ATCC, Old Town Manassas, VA, USA), Escherichia coli ATCC 25922 (ATCC, Old Town Manassas, VA, USA), and Candida albicans ATCC 10231 (ATCC, Old Town Manassas, VA, USA) microbial strains. The antimicrobial assays were done according to a methodology previously reported in [69 (link),70 (link),71 (link),72 (link)], with 0.5 McFarland standard microbial cultures. Afterward, the samples were inoculated using 1.5 mL microbial suspension of a density of 5 × 10⁶ CFU/mL (colony forming units/mL), prepared in phosphate-buffered saline (PBS), and incubated for 24, 48, and 72 h, respectively. As a positive control (C+), free microbial culture was assessed at the same time intervals. Afterward, the suspension was collected at different time intervals (24, 48, and 72 h) and incubated on a LB agar medium for 24 h at 37 °C. The number of CFU/mL was determined for each of the incubated samples with the microbial suspensions. The values of the CFU/mL were determined. The experiments were performed three times and the data were presented as mean ± SD. The statistical analysis was performed using the ANOVA single-factor test.