Antimicrobial activity of varying concentrations of two different chemical solutions against Candida albicans biofilms

Aim To compare the antimicrobial activity of different concentrations
of tetraacetylethylenediamine + sodium perborate
(TAED + P) with that of sodium hypochlorite (NaOCl) against
Candida albicans biofilms.
Methodology Biofilms were generated using cellulose nitrate
membrane filters. Membranes were inoculated with a suspension
of C. albicans in BHI agar. Plates were then incubated for 48 h at
37C. After incubation, the membranes were transferred into tubes
containing 5 mL of the selected antimicrobial solution or sterile saline solution. Samples were taken after 2, 5, 20 and 30 min,
transferred into tubes containing neutralizing broth for 5 min,
diluted and then plated. After incubation, CFU/membrane were
determined. Three replicates were performed for each sample.
Statistical analysis was performed by using ANOVA and Tukey–
Kramer tests at a P level of 0.05 to determine the interaction
between time and concentration of the chemicals tested on biofilm
viability.
Results Significant differences (P < 0.05) were found in the
comparisons of all the concentrations of the two antimicrobial
agents tested, TAED + P, NaOCl against the control group after
each time point. No statistically significant differences were found
between NaOCl and TAED + P solutions when used undiluted or at
high concentrations at various time points. While all concentrations
of NaOCl proved to be effective against C. albicans biofilms after
30 min of exposure, C. albicans biofilms treated with TAED+P were
totally eradicated at 20 and 30 min at all dilutions tested.
Conclusions The antimicrobial agents investigated in this experimental
biofilm model showed a different efficacy correlated with
the concentration and the duration of the exposure. Both TAED + P
and NaOCl were able to completely eliminate C. albicans biofilms at
different exposure times when used at high concentrations,
indicating that TAED + P has at least similar antimicrobial activity
to NaOCl under the conditions tested.