9th International Mycological
Congress, Future strategies for the
control of fungal diseases,
Edinburgh Uk. Aug 1-6 2010.
Antifungal synergy produced in Candida albicans with 870nm/930nm Near
Infrared Photo-damage
E. Bornstein*1, S. Gridley2
1
Nomir Medical Technologies, United States, 2Blue Sky Biotech, United States
We have previously determined that 870nm/930nm near infrared energy will cause photodamage at physiologic temperatures to the fungal pathogens Candida albicans and Trichophyton
rubrum. This was measured as decreased trans-membrane potentials (∆Ψ mt and ∆Ψ p) and
increased radical oxygen species. Herein, we tested Candida albicans ATCC 14053 in vitro, with
a sub-lethal dose of 870nm/930nm laser energy and less than the minimum inhibitory
concentrations of terbinafine (0.5 ug/ml) and itraconazole (0.5 ug/ml), to surmise whether photodamage would synergistically lower the MIC of these antifungals. Irradiation consisted of 8640
J/cm2 over 30 minutes in saline, and samples were plated in quintuplicate.
With both molecules, the combination of sub-inhibitory 870nm/930nm energy and sub-MIC
antifungal concentrations killed ~ 85% more colony forming units than the sum of the individual
activities of each treatment alone, confirming synergy of the antifungal molecules with the light
therapy. There was a statistically significant difference in CFU distribution between Control and
Experimental colonies (terbinafine P=0.0143, and itraconazole P=0.0090).
We suggest that this antifungal synergy results from a photobiological attenuation of ATPdependent macromolecular synthetic pathways, via disruption of ∆Ψ mt and endogenous
generation of ROS, and could potentially be exploited in cutaneous antifungal therapy.
Keywords: Candida, Infrared, Itraconazole, Terbinafine