Cutaneous Mold Infections and Antimicrobial Blue Light

Cutaneous mold infections commonly result from an array of traumatic injuries that involve direct inoculation of contaminated soil into wounds.

Antimicrobial blue light (aBL) and the combination of aBL with quinine hydrochloride (aBL + Q-HCL) is effective for treating mold infections, according to a study published in The Journal of Infectious Diseases.

Primary cutaneous mold infections are especially caused by Aspergillus, Fusarium, Mucor, and Rhizopus spp. These infections may invade deeper tissues and cause disseminated fungal infections in the neutropenic host.

A group of researchers performed a study to explore the use of antimicrobial blue light (aBL; 405 nm wavelength) and the combination of aBL with quinine hydrochloride (aBL + Q-HCL) for the treatment of cutaneous mold infections.

Efficacy of aBL and aBL + Q-HCL in killing clinically important pathogenic molds (Aspergillus fumigatus, Aspergillus flavus, and Fusarium oxyprorum) was investigated. Ultraperformance liquid chromatography identified and quantified endogenous porphyrins in the mold conidia. Finally, a mouse model of dermabrasion wound infected with a bioluminescent variant of A. fumigatus was developed to investigate the efficacy of aBL in treating cutaneous mold infections.

Results of the Study

• Mold conidia are tolerant to aBL, but Q-HCL enhances efficacy.
• Transmission electron microscopy revealed intracellular damage by aBL. aBL + Q-HCL resulted in intracellular and cell wall damage.
• Porphyrins were observed in all mold strains, with A. fumigatus having the highest concentration.
• aBL and aBL + Q-HCL effectively reduced the burden of A. fumigatus within an established dermabrasion infection and limited recurrence posttreatment.

Thus, the researchers concluded that aBL and aBL + Q-HCL may offer a novel approach for the treatment of mold infections.

Reference

Leanse LG, dos Anjos C, Wang Y, Murray CK, Hooper DC, Dai T. Effective treatment of cutaneous mold infections by antimicrobial blue light that is potentiated by quinine. J Infect Dis. 2021;224(6):1024-1028. doi:10.1093/infdis/jiab058