IADR Abstract Archives
Effect of N-acetylcysteine on Candida Albicans Biofilm
Objectives: Candida albicans biofilms are associated with local and systemic infections, are difficult to treat, and tolerant to antifungal agents. The therapies against biofilms are relevant for more effective treatments. This study evaluated the effect of N-acetylcysteine (NAC) in biofilm of C. albicans susceptible (CaS) and resistant to fluconazole (CaR).
Methods: The susceptibility of planktonic cultures of CaS and CaR to NAC was determined by the Minimum Inhibitory/Fungicidal Concentrations (MIC/MFC), and the time-kill curves were performed. The effect of NAC on biofilms formation and mature biofilms (48h) was evaluated by viability (CFU/mL) and total biomass (crystal violet). The data were analyzed by the ANOVA/Welch and Tukey/Gomes-Howell or Kruskal-Wallis tests (α=0.05).
Results: The MIC90 for both strains was 25 mg/mL. Although no CFM value was found, NAC significantly reduced fungal viability by 1.80 to 2.85 log10 for both strains evaluated. NAC 12.5 mg/mL increased the viability of CaS and CaR in 0.3 and 0.57 log10, respectively. For the time-kill curves, only concentrations ≥ MIC reduced fungal growth for 24h, which was more evident between 8-10h. NAC 100 and 50 mg/mL reduced the biofilm formation (1.41 to 2.77 log10, and 39 to 89% of biomass) of both strains, but NAC 12.5 mg/mL increased the viability of CaS (0.74 log10). For mature biofilms, only NAC 100 mg/mL reduced the viability of CaS and CaR in 0.98 and 2.30 log10, respectively, and NAC 50 and 25 mg/mL reduced CaR by 1.26 and 0.64 log10, respectively. NAC 12.5 mg/mL increased the viability of CaS (0.25 log10). NAC 100 mg/mL reduced the biomass in 68% for both strains, and for CaR NAC 50 and 25 mg/mL also reduced the biomass in 64 and 48%, respectively.
Conclusions: NAC showed fungistatic effect against CaS and CaR, with a concentration-dependent effect, and its antibiofilm effect was due to its fungistatic action.
Methods: The susceptibility of planktonic cultures of CaS and CaR to NAC was determined by the Minimum Inhibitory/Fungicidal Concentrations (MIC/MFC), and the time-kill curves were performed. The effect of NAC on biofilms formation and mature biofilms (48h) was evaluated by viability (CFU/mL) and total biomass (crystal violet). The data were analyzed by the ANOVA/Welch and Tukey/Gomes-Howell or Kruskal-Wallis tests (α=0.05).
Results: The MIC90 for both strains was 25 mg/mL. Although no CFM value was found, NAC significantly reduced fungal viability by 1.80 to 2.85 log10 for both strains evaluated. NAC 12.5 mg/mL increased the viability of CaS and CaR in 0.3 and 0.57 log10, respectively. For the time-kill curves, only concentrations ≥ MIC reduced fungal growth for 24h, which was more evident between 8-10h. NAC 100 and 50 mg/mL reduced the biofilm formation (1.41 to 2.77 log10, and 39 to 89% of biomass) of both strains, but NAC 12.5 mg/mL increased the viability of CaS (0.74 log10). For mature biofilms, only NAC 100 mg/mL reduced the viability of CaS and CaR in 0.98 and 2.30 log10, respectively, and NAC 50 and 25 mg/mL reduced CaR by 1.26 and 0.64 log10, respectively. NAC 12.5 mg/mL increased the viability of CaS (0.25 log10). NAC 100 mg/mL reduced the biomass in 68% for both strains, and for CaR NAC 50 and 25 mg/mL also reduced the biomass in 64 and 48%, respectively.
Conclusions: NAC showed fungistatic effect against CaS and CaR, with a concentration-dependent effect, and its antibiofilm effect was due to its fungistatic action.