IADR Abstract Archives
Rapid Fungicidal Activity of Chitosan against Candida albicans
Objectives: Chitosan is a natural product with many favourable properties including antimicrobial activity. We previously found chitosan derivatives that are active against several common oral Candida species. Here, we aim to examine antifungal activity of shrimp chitosan on Candida albicans at various exposure times.
Methods: Log-phase cultures of Candida albicans ATCC 90028 at approximately 106 cells/ml were incubated for various length of time with 1x Minimum Fungicidal Concentration (MFC; 3mg/ml) of chitosan oligomer (7-9 kD) and polymer (900-1,000 kD) (Taming Enterprise, Ltd., Thailand) dissolved in 0.1% acetic acid. In these experiments, media alone or 0.1% acetic acid were included as negative controls and 0.12% chlorhexidine as a positive control. At various time points (1, 3, 5, 10, 30 and 60 minutes), the cells were washed with Yeast Peptone Dextrose (YPD) broth, and serially diluted. Appropriate dilutions were plated on YPD agar plates and incubated at 30°C for 48 hours to determine the number of colonies forming unit (CFU) remaining at each time point. The experiment was repeated 3 times.
Results: Both oligomer and polymer chitosan at the concentration of 3 mg/ml showed time-dependent anti-Candida activity against Candida albicans. They reduced the number of C.albicans by 2 orders of magnitude (99% killing) within 1 minute and by 3 orders of magnitude at later time points. On the other hand, 0.12% Chlorhexidine solution required 10 minutes to achieve a similar level of activity.
Conclusions: Oligomer and polymer chitosan has rapid fungicidal activity and could kill 99% of Candida albicans cells within 1 minute of exposure.
Methods: Log-phase cultures of Candida albicans ATCC 90028 at approximately 106 cells/ml were incubated for various length of time with 1x Minimum Fungicidal Concentration (MFC; 3mg/ml) of chitosan oligomer (7-9 kD) and polymer (900-1,000 kD) (Taming Enterprise, Ltd., Thailand) dissolved in 0.1% acetic acid. In these experiments, media alone or 0.1% acetic acid were included as negative controls and 0.12% chlorhexidine as a positive control. At various time points (1, 3, 5, 10, 30 and 60 minutes), the cells were washed with Yeast Peptone Dextrose (YPD) broth, and serially diluted. Appropriate dilutions were plated on YPD agar plates and incubated at 30°C for 48 hours to determine the number of colonies forming unit (CFU) remaining at each time point. The experiment was repeated 3 times.
Results: Both oligomer and polymer chitosan at the concentration of 3 mg/ml showed time-dependent anti-Candida activity against Candida albicans. They reduced the number of C.albicans by 2 orders of magnitude (99% killing) within 1 minute and by 3 orders of magnitude at later time points. On the other hand, 0.12% Chlorhexidine solution required 10 minutes to achieve a similar level of activity.
Conclusions: Oligomer and polymer chitosan has rapid fungicidal activity and could kill 99% of Candida albicans cells within 1 minute of exposure.