Antimicrobial blue light and quinine combo effective for treatment of mold infections: Study

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.

The results of the study are as follows:

• 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