Efficacy of antifungal agents against fungal spores: An in vitro study using microplate laser nephelometry and an artificially infected 3D skin model

Abstract

Dermal fungal infections seem to have increased over recent years. There is further a shift from anthropophilic dermatophytes to a growing prevalence of zoophilic species and the emergence of resistant strains. New antifungals are needed to combat these fungi and their resting spores. This study aimed to investigate the sporicidal effects of sertaconazole nitrate using microplate laser nephelometry against the microconidia of Trichophyton , chlamydospores of Epidermophyton , blastospores of Candida , and conidia of the mold Scopulariopsis brevicaulis . The results obtained were compared with those from ciclopirox olamine and terbinafine. The sporicidal activity was further determined using infected three‐dimensional full skin models to determine the antifungal effects in the presence of human cells. Sertaconazole nitrate inhibited the growth of dermatophytes, molds, and yeasts. Ciclopirox olamine also had good antifungal activity, although higher concentrations were needed compared to sertaconazole nitrate. Terbinafine was highly effective against most dermatophytes, but higher concentrations were required to kill the resistant strain Trichophyton indotineae . Sertaconazole nitrate, ciclopirox olamine, and terbinafine had no negative effects on full skin models. Sertaconazole nitrate reduced the growth of fungal and yeast spores over 72 h. Ciclopirox olamine and terbinafine also inhibited the growth of dermatophytes and molds but had significantly lower effects on the yeast. Sertaconazole nitrate might have advantages over the commonly used antifungals ciclopirox olamine and terbinafine in combating resting spores, which persist in the tissues, and thus in the therapy of recurring dermatomycoses.

Small, Cationic Antifungal Proteins from Filamentous Fungi Inhibit Candida albicans Growth in 3D Skin Infection Models

“…To follow the induction of the innate immune response in the skin model, the secreted (pro-) inflammatory cytokines IL-6 and IL-8 were quantified in CCM collected after 48 h of incubation. IL-6 and IL-8 are expressed in keratinocytes and fibroblasts in response to fungal infection and secreted in sufficient amounts to be detectable by enzyme-linked immunosorbent assay (ELISA) in the CCM of skin models ( 38 , 40 , 43 ). As shown in Fig.…”

“…These models can be purchased commercially and represent a feasible alternative to animal testing for pathophysiological studies and pharmacological investigations ( 36 , 37 ). Some publications reported on the use of human 3D FT models to study the fungal infection of the skin and test new antifungal compounds ( 38 – 40 ).…”

Effects of Histamine and the α-Tocopherol Metabolite α-13′-COOH in an Atopic Dermatitis Full-Thickness Skin Model

“…Full-thickness skin models were cultured based on previous publications [ 69 , 70 , 71 ]. Normal human dermal fibroblasts (Promocell, Sickingenstrasse, Heidelberg, Germany) were cultured in Dulbecco’s modified Eagle’s medium (DMEM; BioConcept, Paradiesrain, Alschwil, Switzerland) supplemented with 2% fetal calf serum (FCS; PAN-Biotech, Gewerbepark, Aidenbach, Germany), 0.5% gentamicin (Thermo Fisher, Waltman, MA, USA), 5 μg/mL insulin and 5 ng/mL human fibroblastic growth factor (Cellsystems, Triosdorf, Germany) at 37 °C in a 5% CO 2 atmosphere to approximately 90% confluence.…”

Cold Atmospheric Plasma Exerts Antimicrobial Effects in a 3D Skin Model of Cutaneous Candidiasis

“…The skin models exhibited a fully differentiated epidermis consisting of stratum basale, stratum spinosum, stratum granulosum, and stratum corneum (Figure 2a). The thickness of the dermis was less pronounced compared to other full skin models [15] as no additional matrix was provided for the skin model [16,17]. PAS (periodic acid-Schiff) staining allowed easy distinction of the hyphal growth of C. albicans in the infected models.…”

“…Three-dimensional skin models were manufactured as previously reported [16,17]. C. albicans (ATCC MYA-2876) was cultured on Sabouraud Dextrose Agar (SDA) plates (bioMérieux, Craponne, France).…”