Updating Corneofungimetry: A Bioassay Exploring Dermatomycoses and Antifungal Susceptibility

Abstract

Superficial dermatomycoses are frequent conditions in humans and animals. Specific treatment modalities have been designed using a variety of different antifungal compounds. The need for antifungal susceptibility testing (AST) has been growing steadily over the last two decades due to the extending number of newer antifungal agents. Objective inter- and intraindividual comparisons of their respective efficacies are nearly impossible to perform in vivo. Currently, a series of standardized AST methods and interpretative guidelines have been designed. However, their clinical relevance for dermatomycoses is not consistent. The corneofungimetry bioassay was designed to test comparatively a series of antifungals on pathogenic fungi growing on sheets of human stratum corneum. Computerized morphometric assessments bring numerical values allowing statistical comparisons. Variants of corneofungimetry address more specific aspects related to fungal cell adhesion, fungitoxicity and lipid-dependent fungi.

Dermatophyte Growth in Glabrous Skin Dermatophytoses of Immuno Compromised Hosts

“…In experimental settings, some analytical assessments of disease severity and therapeutic activity on dermatophytoses are possibly performed on CSSS using computerized image analysis of the corneofungimetry bioassay [17][18][19][20][21]. Beyond conventional antifungigrams [22] quantifications of the restricted fungal extent following antifungals are conveniently performed in experimental dermatomycosis [10,17,23]. Oral or topical antifungals are initially administered to healthy volunteers for a defined restricted period of time (usually a couple of days) before CSSS samplings.…”

“…Corneofungimetry has some advantages over conventional in vitro anti fungigrams that are clearly influenced by both the culture medium composition and the physiological state of the microorganism [23]: (a) the treatment is applied in vivo in conditions normally encountered by patients, (b) the initial fungal load is possibly controlled, (c) the growth substrate is only composed of corneocytes without any additional compounds, and (d) any influence of corneocytes including natural antimicrobial peptides and Toll-like receptors is respected. An appropriate choice of treatment is helped by this procedure, and should reduce some inappropriate therapeutic decisions [24].…”

Cyanoacrylate Skin Surface Stripping and the 3S-Biokit Advent in Tropical Dermatology: A Look from Liège

“…In particular, some quantifications of dermatomycosis severity and antifungal activity are performed using corneofungimetry on CSSS [31, 32]. Microscopic fungi can be cultured in vitro using corneocytes as a growth substrate, particularly on CSSS.…”