Melanogenesis in dermatophyte species in vitro and during infection

• DOI: 10.1099/mic.0.047928-0
• Publication Date: 2011-05-13T01:16:26Z
• Authors: Sirida Youngchim; Soraya Pornsuwan; Joshua D. Nosanchuk; Wiyada Dankai; Nongnuch Vanittan...
• Keywords: Microsporum gypseum; Dermatophyte; Epidermophyton floccosum

Dermatophytes are keratinophilic fungi that the most common cause of fungal skin infections worldwide. Melanin has been isolated from several important human pathogens, and polymeric pigment is now recognized as an virulence determinant. This study investigated whether dermatophytes, including Trichophyton rubrum , mentagrophytes Epidermophyton floccosum Microsporum gypseum, produce melanin or melanin-like compounds in vitro during infection. Digestion pigmented microconidia macroconidia dermatophytes with proteolytic enzymes, denaturant hot concentrated acid yielded dark particles retained size shape original cells. Electron spin resonance spectroscopy revealed derived conidia contained a stable free radical signal, consistent pigments being melanin. Immunofluorescence analysis demonstrated reactivity melanin-binding mAb hyphae, well isolate particles. Laccase, enzyme involved melanization, was detected by agar plate assay using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) substrate. Skin scrapings patients dermatophytoses septate hyphae arthrospores were reactive mAb. These findings indicate can Based on what known about function factor other pathogenic fungi, this may have similar role pathogenesis dermatophytic diseases.