This study sheds light on biofilms of different dermatophyte species, which will contribute to a better understanding of the pathophysiology of dermatophytosis. Further studies of this type are necessary to investigate the processes involved in the formation and composition of dermatophyte biofilms.

1. The study of changes that persist after drug discontinuation could be fundamental to understand the mechanisms involved in craving and relapse. 2. In this work the changes occurring in muscarinic, D1- and D2-like receptors after 30 min (immediate), 1 day (early), 5 and 30 days (late) withdrawal periods were studied, in the striatum of rats treated once a day for 7 days with cocaine 20 and 30 mg/kg, i.p. 3. Binding assays were performed in 10% homogenates and ligands used were [3H]-N-methylscopolamine, [3H]-SCH 23390, and [3H]-spiroperidol for muscarinic (M1 + M2-like), D1-, and D2-like receptors, respectively. 4. Muscarinic receptors presented a downregulation at all doses and discontinuation times, while the dissociation constant (Kd) for this receptor decreased after 30 min, 5 and 30 days abstinence times. In relation to D1-like receptors we found an antagonistic effect with 100% increase in receptor number 30 min after the last cocaine injection, but after 1-day withdrawal a downregulation was observed with both doses that persisted up to 30 days, only with the higher dose. The dissociation constant value (Kd) for this receptor showed a decrease only with 5 and 30 days withdrawal. An increase occurred with D2-like receptors at all doses and withdrawal periods studied, while Kd increased in 30-min, 5, and 30 days withdrawal. 5. In this work we found that the subchronic cocaine treatment produces early and long-lasting modifications in cholinergic muscarinic as well in dopaminergic receptors that persist up to 30 days of cocaine withdrawal.

Sporotrichosis, caused by species of Sporothrix schenckii complex, is the most prevalent subcutaneous mycosis in many areas of Latin America. The aim of this study was to evaluate the ability of Sporothrix spp. to form biofilms in vitro and to characterize the growth kinetics, morphology, and antifungal susceptibility of biofilms against classical antifungals. We investigated the ability of strains to produce biofilms in vitro and determined the effects of exposure to amphotericin B, itraconazole, caspofungin, ketoconazole, voriconazole, and fluconazole at minimum inhibitory concentration (MIC) against planktonic form and at 10× MIC and 50× MIC on the biomass and metabolic activity of these biofilms. Biofilm structure was analyzed by optical microscopy using Congo-red staining, confocal and scanning electron microscopy. Strains were classified for biofilm-forming ability, through the analysis of absorbance of crystal violet retained by biomass of mature biofilms. We found that all S. brasiliensis (n = 10), S. schenckii sensu stricto (n = 2), S. globosa (n = 2), and S. mexicana (n = 4) strains were strong biofilm-producers. The analyzed biofilms had dense network of hyphae and conidia immersed in extracellular matrix, with presence of water channels. Antifungal drugs at the three tested concentrations showed different effects on biomass and metabolic activity of biofilms. However, the best inhibitory response was observed with 50× MIC of amphotericin B and caspofungin, which reduced these parameters. Furthermore, high drug concentrations, especially amphotericin B and caspofungin, showed antifungal activity against these biofilms, probably because they damaged the architecture and extracellular matrix, allowing diffusion of the drugs.

As shown by recent research, most of the clinically relevant fungi, including dermatophytes, form biofilms in vitro and in vivo, which may exhibit antimicrobial tolerance that favour recurrent infections. The aim of this study was to determine the minimum inhibitory concentrations (MICs) of itraconazole (ITC), voriconazole (VCZ) and griseofulvin (GRI) against Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum in planktonic and biofilm growth. For the planktonic form, susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI), document M38-A2, while biofilm susceptibility was evaluated using the XTT colorimetric essay. The planktonic growth of all strains was inhibited, with MIC values ranging from 0.00195 to 0.1225 μg/mL for VRC, 0.00195 to 0.25 μg/mL for ITC and <0.0039 to 4 μg/mL for GRI, while a 50-fold increase in the MIC was required to significantly reduce the metabolic activity (P < .05) of dermatophyte biofilms. In brief, the ability of dermatophytes to form biofilms may be a contributing factor for the recalcitrance of dermatophytoses or the dissemination of the disease.

Dermatophytoses are infectious skin diseases of public health importance because of their transmissibility and high prevalence, especially among school-age children. This is the first study aiming to estimate and report the burden of dermatophytoses on school-age children in Cape Verde. Children attending the afternoon shift of three elementary schools in the city of Achada Igreja, Cape Verde were observed; samples were collected from 60 students with suspected lesions, including hair, nails, and skin scraping. A total of 19 dermatophyte isolates were obtained, corresponding to a point prevalence of 7.63%. Morphological species identification demonstrated 3 different species Trichophyton soudanense, Trichophyton rubrum, and Trichophyton violaceum; re-identification by sequencing the (Internal transcribed spacer) ITS-5.8S rDNA region revealed T. soudanense as the most prevalent species, with only one case of T. rubrum. We document T. soudanense infections in the skin, nails, and scalp, and not only as an agent of tinea capitis as described before. This study reinforces the need of using culture and accurate identification methodologies for gathering epidemiological trends of dermatophytoses throughout the archipelago, especially in school-age students.

Withania chevalieri, endogenous from Cape Verde, is a medicinal plant used in ethnomedicine with a large spectrum of applications, such as treating skin fungal infections caused by dermatophytes. The aim of this work was to chemically characterize the W. chevalieri crude ethanolic extract (WcCEE), and evaluate its bioactivities as antidermatophytic, antioxidant, anti-inflammatory and anticancer, as well as its cytotoxicity. WcCEE was chemically characterized via HPLC–MS. The minimal inhibitory concentration, minimal fungicidal concentration, time-kill and checkerboard assays were used to study the antidermatophytic activity of WcCEE. As an approach to the mechanism of action, the cell wall components, β-1,3-glucan and chitin, and cell membrane ergosterol were quantified. Transmission electron microscopy (TEM) allowed for the study of the fungal ultrastructure. WcCEE contained phenolic acids, flavonoids and terpenes. It had a concentration-dependent fungicidal activity, not inducing relevant resistance, and was endowed with synergistic effects, especially terbinafine. TEM showed severely damaged fungi; the cell membrane and cell wall components levels had slight modifications. The extract had antioxidant, anti-inflammatory and anti-cancer activities, with low toxicity to non-tumoral cell lines. The results demonstrated the potential of WcCEE as an antidermatophytic agent, with antioxidant, anti-inflammatory and anticancer activity, to be safely used in pharmaceutical and dermocosmetic applications.