In vitro and in vivo efficacy of miramistin against drug-resistant fungi.

Abstract

Miramistin is a topical antiseptic with broad antimicrobial activity that was developed in the Soviet Union during the Cold War. To investigate the antifungal activity of miramistin against clinically relevant drug-resistant fungi. The in vitro activity of miramistin was determined following Clinical and Laboratory Standards Institute (CLSI) guidelines. Mammalian cell toxicity was tested using a McCoy cell line and topical and systemic tolerability, and in vivo efficacy was tested using Galleria mellonella models. The minimal inhibitory concentration (MIC) range against fungi was 1.56-25 mg l-1 (GM 3.13 mg l-1 ). In the G. mellonella model, miramistin provided potent survival benefits for Candida albicans and Aspergillus fumigatus infection. Miramistin was tolerated by McCoy cell lines at concentrations up to 1000 mg l-1 and was systemically safe in G. mellonella at 2000 mg kg-1. Topical administration at 32 000 mg l-1 was well tolerated with no adverse effects. These findings support further investigation of miramistin and suggest its possible use for treatment of superficial fungal infections.