The Iron-Hydrogen Peroxide-Iodide System Is Fungicidal: Activity Against the Yeast Phase of Blastomyces dermatitidis

Abstract

A series of experiments show the potency of a newly described microbicidal system, involving iron, H₂O₂, and halide, in killing a fungus (Blastomyces dermatitidis). B dermatitidis has previously been shown susceptible to the myeloperoxidase-H₂O₂ halide system. The present studies show killing of either of two strains in 1 hour if Fe^{+ +} at 5 × 10⁻⁵M, H₂O₂ at 5 × 10⁻M and Kl at 5 × 10⁻⁴M are all present (P < 0.001). EDTA, a Fe^{+ +} chelator, abrogates killing. The mechanism presumably utilizes hydroxyl radical, since an inhibitor, ethanol, also neutralizes the system. The bactericidal and fungicidal system is of great potential importance in vivo.