Antimicrobial blue light therapy for<i>Candida albicans</i>burn infection in mice

In this preclinical study, we investigated the utility of antimicrobial blue light therapy for <i>Candida albicans </i>infection in acutely burned mice. A bioluminescent strain of <i>C. albicans </i>was used. The susceptibilities to blue light inactivation were compared between<i> C. albicans </i>and human keratinocyte. <i>In vitro </i>serial passaging of<i> C. albicans </i>on blue light exposure was performed to evaluate the potential development of resistance to blue light inactivation. A mouse model of acute thermal burn injury infected with the bioluminescent strain of<i> C. albicans </i>was developed. Blue light (415 nm) was delivered to mouse burns for decolonization of <i>C. albicans</i>. Bioluminescence imaging was used to monitor in real time the extent of fungal infection in mouse burns. Experimental results showed that<i> C. albicans </i>was approximately 42-fold more susceptible to blue light inactivation in vitro than human keratinocyte (<i>P</i>=0.0022). Serial passaging of <i>C. albicans </i>on blue light exposure implied a tendency for the fungal susceptibility to blue light inactivation to decrease with the numbers of passages. Blue light reduced fungal burden by over 4-log₁₀ (99.99%) in acute mouse burns infected with <i>C. albicans </i>in comparison to infected mouse burns without blue light therapy (<i>P</i>=0.015).