Antifungal Photodynamic Therapy of Vaginal Candidiasis

Aim: The aim of this study to evaluate the photosensitizing efficacy of a cationic meso-tetrakis porphine on C. albicans and C. krusei.Design: An experimental in vitro study.Setting: National Institute of Enhanced Laser Science, Cairo University. Materials and Methods: Micro-organisms: C. albicans and C. krusei strains were isolated from the vagina and were prepared with a final cell concentration of the suspension of lx 106 cell/ml. Sample of the final concentrate from each strain was obtained and divided into 4 groups. Group I were irradiated with 632.8nm laser light after incubation with photosensitizer [meso-tetrakis (N-methyl-4-pyridyl) porphine], (L+P+). Group II were irradiated only with laser light (L+P-). Group III were exposed with photosensitizer only (L-P+). Group IV were neither exposed to laser nor to photosensitizer (L-P-) and were considered as controls. The photosensitizer, was used in the concentration of 1, 0.5, 0.2 and 0.1 µM. Helium Neon laser emitting light at wavelength of 632.8nm, with output power 5.5mW was used with irradiation time 5, 10, 15, 20, 25 and 30min. Outcome measures: The number of Candida colonies were determined by direct plate enumeration and expressed as percentage of CFU/ml reduction for each species for the different groups of the study. Transmission electron microscopy was performed prior and after laser photosensitization. Results: The percentage of reduction of CUF/ml increased dramatically with increasing the concentration of the photosensitizer, after laser irradiation, with significant effect at the higher concentration of 1µM. The lethal effect was more significant on the C. krusei than C. albicans (77.1% and 47.9% respectively) after 15min exposure. This reduction reached to 83% and 89% in case of C. albicans and C. krusei respectively. The sole use of laser radiation did not have any effect and the isolate use of photosensitizer did not reduce significantly the number of CFU/ml of C. albicans or C. krusei samples. Conclusion: Photodynamic activation of meso-tetrakis porphine by the Helium Neon laser irradiation at a wavelength of 632.8nm presented fungicide effect on all C. albicans and C. krusei.