Effects of Cosmetic Preservatives on Healthy Facial Skin Microflora.

Objective: The present study was designed to evaluate the effects of seven common preservatives used in Iranian cosmetic products on facial skin microflora. Methods: Fifteen healthy volunteers, aged 20 to 35 years, were recruited. Three symmetrical sites from the cheeks of each volunteer were selected and samples were collected. DNA was extracted from the culture using the boiling method. The fungi's internal transcribed spacer (ITS) region was amplified using ITS1/ITS4 primers, for 16s to identify bacteria and Staphylococcus specific primers. The effects of the preservatives were assessed based on growth on broth culture media. Results: Primary identification was based on yeast on CHROM agar, in which 15 different yeasts were isolated; then, PCR was used to identified the species as: C. albicans (n: 14; 93%), C. orthopsilosis (n: 1; 7%). One primary identified yeast on Dixon media was precisely differentiated as M. furfur using the PCR method. Fifteen primary identified cocci on tryptic soy agar media were identified as Staphylococcus epidermis. All the preservatives showed to inhibit the growth of isolated fungi, but not that of bacterial microflora. Conclusion: The present study showed preservatives in cosmetic products can alter skin microflora while also preventing the growth of pathogenic bacteria.

The in vitro effect of nanoliposomal amphotericin B against two clinically important dermatophytes.

AIMS: The present study aimed to investigate the antifungal activity of amphotericin B-loaded nanoliposomes against Trichophyton interdigitale and Trichophyton rubrum. Moreover, it was attempted to assess the obtained resistance in vitro. METHODS: In total, 29 archived clinical strains, namely, T. interdigitale (n = 16) and T. rubrum (n = 13), were included in this study. These strains were determined using a previous ITS1-ITS2 region sequence. Moreover, a liposomal formulation of amphotericin B was formulated by a thin-film hydration method. Particle size, polydispersity index (PdI), and zeta potential (ZP) were measured by a Zetasizer. Furthermore, physicochemical properties, such as appearance, aggregation of particles, particle size, PdI, and ZP, were determined at 0-, 1-, and 3-month intervals. A scanning electron microscope (SEM) was also used to examine nanoparticles structure. The minimum inhibitory concentration (MIC) of amphotericin B-loaded nanoliposomes, itraconazole, efinaconazole, terbinafine, and ciclopirox was determined according to the protocol of the broth microdilution method of CLSI M38-A2. The morphological changes of T. interdigitale and T. rubrum strains exposed to the amphotericin B-loaded nanoliposomes were observed using SEM. RESULTS: The amphotericin B-loaded nanoliposomes displayed a lower MIC compared to those of the amphotericin B and liposomes when used separately. Based on the results, amphotericin B-loaded nanoliposomes induced no drug resistance in any of the tested strains. CONCLUSION: Accordingly, amphotericin B-loaded nanoliposomes can be a potent antifungal for the topical treatment of onychomycosis. There was no in vitro evidence regarding the resistance of the tested strains to amphotericin B-loaded nanoliposomes. This reflects that amphotericin B-loaded nanoliposomes have a low probability to induce drug resistance in dermatophyte species.

Drug Sensitivity Profile of Fungi Isolated from Onychomycosis Patients and Evaluation of Squalene Epoxidase Mutation in One Terbinafine-Resistant Trichophyton mentagrophytes Species.

Background: The resistance to treatment of onychomycosis is increasingly reported. The present study aimed to assess the antifungal activity of itraconazole, terbinafine, luliconazole, and efinaconazole against dermatophytes, molds, and also yeast isolated from patients with onychomycosis. Furthermore, the mechanism of resistance to terbinafine in resistant Trichophyton mentagrophytes species was evaluated using the squalene epoxidase (SQLE) gene sequence. Methods: A total of 71 fungal isolates were collected from 97 patients with suspected onychomycosis. The identification of fungal species was performed using conventional and molecular approaches. In vitro drug susceptibility for itraconazole, terbinafine, luliconazole, and efinaconazole was carried out using the broth microdilution method according to the CLSI-M60 and CLSI-M38 3rd ed., respectively. The SQLE gene of one terbinafine-resistant T. mentagrophytes was amplified using the specific primers. Results: Efinaconazole and luliconazole demonstrated higher effectiveness against all isolates in the study. One mismatch was detected at position 1177, which showed A → C change associated with Phe397Leu amino acid substitution of the SQLE protein in terbinafine-resistant T. mentagrophytes. Conclusion: The occurrence of resistant strains of organisms causing onychomycosis should be considered and evaluated. Furthermore, the identification of amino acid changes responsible for resistance to antifungals is a useful consideration in drug-target interaction.