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In vitro susceptibility of Candida albicans to four disinfectants and their combinations
T M Waltimo1, D Orstavik, E K Sirén
1NIOM, Scandinavivan Institute of Dental Materials, Haslum, Norway. tuomas.waltimo@helsinki.fi
Aim:
The aim of this study was to evaluate the susceptibility of seven strains of Candida albicans to four disinfectants: iodine potassium iodide, chlorhexidine acetate, sodium hypochlorite and calcium hydroxide. In addition, all possible pairs of the disinfectants were tested in order to compare the effect of the combination and its components.
Methodology:
Filter paper discs were immersed in standardized yeast suspensions and then transferred to disinfectant solutions of different concentrations and incubated at 37 degrees C for 30 s, 5 min, 1 h and 24 h. After incubation the filter paper discs were transferred to vials with PBS and glass beads that were then vigorously shaken for dispersal of the yeast cells. PBS with resuspended yeasts was serially diluted 10-fold. Droplets of 25 microL from each dilution were inoculated on TSB agar plates and incubated in air at 37 degrees C for 24 h. The number of colony-forming units was then calculated from appropriate dilutions.
Results:
C. albicans cells were highly resistant to calcium hydroxide. Sodium hypochlorite (5% and 0.5%) and iodine (2%) potassium iodide (4%) killed all yeast cells within 30 s, whilst chlorhexidine acetate (0.5%) showed complete killing after 5 min. Combinations of disinfectants were equally or less effective than the more effective component. All C. albicans strains tested showed similar susceptibility to the medicaments tested.
Conclusions:
This study indicates that sodium hypochlorite, iodine potassium iodide and chlorhexidine acetate are more effective than calcium hydroxide against C. albicans in vitro. However, combining calcium hydroxide with sodium hypochlorite or chlorhexidine may provide a wide-spectrum antimicrobial preparation with a long-lasting effect.
Insights
Sodium hypochlorite, iodine potassium iodide, and chlorhexidine acetate effectively kill Candida albicans. Calcium hydroxide is less effective, but combinations may offer broad-spectrum antimicrobial action.
Area of Science:
- Microbiology
- Antimicrobial agents
- Infection control
Background:
- Candida albicans is a common opportunistic fungal pathogen.
- Effective disinfection is crucial for preventing C. albicans infections.
Purpose of the Study:
- To evaluate the efficacy of four disinfectants against Candida albicans.
- To compare the effectiveness of disinfectant combinations.
Main Methods:
- Susceptibility testing of seven C. albicans strains.
- Exposure to disinfectants (iodine potassium iodide, chlorhexidine acetate, sodium hypochlorite, calcium hydroxide) at various concentrations and time points.
- Colony-forming unit counts to determine microbial viability.
Main Results:
- Sodium hypochlorite and iodine potassium iodide demonstrated rapid killing of C. albicans.
- Chlorhexidine acetate showed complete killing within 5 minutes.
- Calcium hydroxide exhibited high resistance from C. albicans cells.
Conclusions:
- Sodium hypochlorite, iodine potassium iodide, and chlorhexidine acetate are potent in vitro disinfectants against C. albicans.
- Combining calcium hydroxide with sodium hypochlorite or chlorhexidine acetate may yield enhanced, broad-spectrum antimicrobial preparations.