In vitro Antifungal Activities of Several Disinfectants Against Candida Species

Park, Chin Young; Kim, Su Chul; Lee, Seung Chul; Kim, Young Pyo; Won, Young Ho

Abstract

BACKGROUND: The increased incidence of fungemia by hospital-acquired infection necessitates reevaluation of fungicidal activities of antiseptics and disinfectants.
OBJECTIVE
We examined the candidacidal activity of several disinfectants including ethanol, phenol, povidone-iodine, and methanol which has been used commonly in the hospital. Candidal species tested were Candida albicans, Candida krusei, Candida parapsilosis and Candida guillermondii.
METHODS
All candidial stains were cultured in Sabouraud-dextrose agar (SDA), and the spore numbers of them were measured by a hemocytometer. After candidial suspensions were mixed with disinfectants of different concentration for 30 second, they were washed with physiologic saline to remove disinfectants. The suspensions were adjusted into 1x10(4) cfu/ml and were cultured in SDA at 30 degrees C for 72 hours. Minimal fungicidal concentration (MFC) was defined as the minimum concentration of a disinfectant to effect no growth of candidial strains. Minimal inhibitory concentration (MIC) was defined as the minimum concentration of a disinfectant to effect minimum growth of candidial strains.
RESULTS
Our results showed that MFCs of candidial strains were 30~45% in Ethanol, 40~55% in methanol, 0.025~0.06% in povidon-iodine and 1~2% in phenol. All strains tested were killed by ethanol, methanol and povidone-iodine within 2 min at MIC, except phenol.
CONCLUSION
In conclusion, concentrations of disinfectants generally used in the hospital are sufficient to kill candidial strains. Careful procedure should be done in mycologic studies to eliminate the fungicidal effect of disinfectants.