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Super-paramagnetic iron oxide nanoparticles were synthesized by a co-precipitation method, which was further functionalized with chitosan (CS). The composite was investigated for binding with Nystatin (Nyst), a polyene polyhydroxy antifungal widely used in management of mucocutaneous fungal infections. The structure of the Fe3O4/CS/Nyst composite was characterized by different physicochemical techniques. Transmission electron microscope analysis revealed the Fe3O4/CS/Nyst composite with a mean diameter of ∼10–20 nm in a monodispersed spherical form. Fourier-transform infrared spectroscopy analysis confirmed the binding of CS on Fe3O4 NPs and also the loading of Nyst on the nanostructure. The UV–Vis absorption spectroscopy demonstrated the Nyst drug loading by 22% capacity. The antifungal activity of the Fe3O4/CS/Nyst was evaluated against Candida species and Aspergillus fumigatus, which demonstrated excellent activity with a minimum inhibitory concentration ranging from 2 to 16 μg/mL. The MTT assay was used to evaluate the toxicity of compounds which did not reveal any toxic effect on the adipose derived mesenchymal stem cells. Regarding remarkable antifungal activities and low toxicity of this magnetic nano-compound, it could be a good candidate for target therapy of mucocutaneous and local fungal infections. [ABSTRACT FROM AUTHOR]

Candida onychomycosis is a common fungal infection affecting the nails, primarily caused by Candida (C.) species. Regarding the increasing trend of Candida onychomycosis and the antifungal resistant phenomenon in recent years, this study aims to evaluate the epidemiological characteristics of Candida onychomycosis, the distribution of emerging species, and the antifungal susceptibility profiles of isolates. Onychomycosis caused by yeast species was confirmed through direct examination and culture of nail scraping among all individuals suspected to have onychomycosis and referred to a medical mycology laboratory between June 2019 and March 2022. Species of yeast isolates were identified using the multiplex PCR and PCR-RFLP methods. The antifungal susceptibility of isolates to common antifungal agents and imidazole drugs was evaluated according to the M-27-A3 CLSI protocol. Among 101 yeast strains isolated from onychomycosis, Candida parapsilosis complex (50.49%) was the most common species, followed by C. albicans (20.79%) and C. tropicalis (10.89%). Rare species of yeasts such as C. guilliermondii and Saccharomyces cerevisiae were also identified by molecular methods. Results obtained from antifungal susceptibility testing showed significant differences in MIC values of isoconazole, fenticonazole, and sertaconazole among different species. Overall, a fluconazole-resistant rate of 3% was found among Candida species. Moreover, there was a statistically significant difference in MICs of fenticonazole and clotrimazole between the two most prevalent causative species, C. parapsilosis complex and C. albicans. Correct identification of the causative agents of onychomycosis and performing susceptibility testing could be helpful in choosing the most appropriate antifungal therapy. [ABSTRACT FROM AUTHOR]

Background: The ability of dermatophytes to develop biofilm, as one of the virulence factors in fungal infections which contribute to antifungal resistance, is an outstanding aspect of dermatophytosis that has been noted recently. Because of the paucity of data about the biofilm formation by dermatophytes and their susceptibility to antifungal drugs, this study evaluated the biofilm formation by clinical isolates of dermatophytes and antibiofilm activity of common antifungals widely used to manage dermatophytosis. Methods: The ribosomal DNA internal transcribed spacer (ITS) regions sequencing for species identification of 50 clinical dermatophyte isolates was performed. The ability of isolates to form biofilm and inhibitory activity of itraconazole, terbinafine, and griseofulvin against biofilm formation was assayed by the crystal violet staining method. Optical microscopy and scanning electron microscopy (SEM) were applied for the visualization of the biofilm structures. Results: Trichophyton (T.) mentagrophytes (n: 14; 28%) and T. rubrum (n: 13;26%) were included in more than half of the dermatophyte isolates. Biofilm formation was observed in 37 out of 50 (74%) isolates that were classified as follows: nonproducers (n: 13; 26%), weak producers (n: 4; 8%), moderate producers (n: 16; 32%), and strong producers (n: 17; 34%) by comparison of the absorbance of biofilms produced by clinical strains with control. The mean IC50 values for terbinafine, griseofulvin, and itraconazole were 2.42, 3.18, and 3.78 μg/ml, respectively. Conclusions: The results demonstrated that most of the clinical dermatophyte isolates are capable to form biofilm in vitro with variable strength. Moreover, terbinafine can be suggested as the first‐line choice for the treatment of biofilm‐formed dermatophytosis. [ABSTRACT FROM AUTHOR]

Background and Purpose: Candida species are opportunistic fungal pathogens that cause mild to life-threatening infections in both immunocompetent and immunocompromised populations. The increasing prevalence of drug-resistant Candida species has posed a significant challenge to the management of infections in clinical settings. Therefore, this study aimed to investigate the direct antifungal and antibiofilm effect of vitamin D 3 against Candida species., Materials and Methods: The antifungal activity of vitamin D 3 was evaluated by broth microdilution method based on the Clinical and Laboratory Standard Institute. Prevention of biofilm formation by Candida albicans was measured using the XTT assay following exposure to different concentrations of vitamin D 3 . Moreover, expression of Agglutinin-like sequence gene 1 ( ALS 1), hyphal wall protein gene ( HWP 1), secreted aspartyl proteinase 6 gene ( SAP 6), and morphogenesis pathway regulatory gene ( EFG 1) were analyzed by real-time polymerase chain reaction using the comparative Ct method (ΔΔ Ct) after exposure to vitamin D 3 ., Results: Vitamin D 3 showed antifungal activity against Candida species ranging from 1-128 μg/mL. Furthermore, vitamin D 3 inhibited biofilm formation in a dose-dependent manner, with IC50 of 7.5 μg/mL. Treatment with vitamin D 3 resulted in significant upregulation of the EFG 1, ALS 1, and SAP 6 genes under hypha-inducing conditions to overcome environmental challenges., Conclusion: Results of the current study demonstrated that vitamin D 3 has a significant inhibitory effect on Candida growth and biofilm formation. Considering its demonstrated antifungal and antibiofilm properties, vitamin D 3 holds promise as a potential agent for medical applications., Competing Interests: The Authors declare that there is no conflict of interest., (Copyright: © 2021, Published by Mazandaran University of Medical Sciences on behalf of Iranian Society of Medical Mycology and Invasive Fungi Research Center.)

Background: Noble metal nanoparticles, due to their good physicochemical properties, have been exploited in biological applications. Among these metals, nanosilver has attracted great attention because of its optical properties and broad-spectrum antimicrobial activities with no drug tolerance., Purpose: The present study has attempted to conduct chemical synthesis of Fe 3 O 4 @PEG-Ag core/shell nanocomposites in aqueous solutions through co-precipitation of Fe 3+ and Fe 2+ ions, encapsulating the iron oxide core by poly (ethylene-glycol) (PEG) improve its hydrophilicity and biocompatibility, and immobilizing silver ions by application of NaBH 4 as a reducing agent., Patients and Methods: The synthesized structures were characterized by Fourier-transform infrared (FT-IR), field emission scanning electron microscopy, energy-dispersive X-ray spectrum, wavelength-dispersive X-ray, vibrating sample magnetometer, inductively coupled plasma-mass spectrometry and transmission electron microscopy methods. Antimicrobial activity of the nanostructures against Staphylococcus aureus , Escherichia coli and Candida albicans was evaluated by broth microdilution based on the methods suggested by Clinical Laboratory Standard Institute. Furthermore, the nanocomposite was tested for possible anti-parasitic effects against Leishmania major promastigotes by MTT assay. Also, its impacts on bacterial cell morphology were defined using atomic force microscopy. Moreover, toxicity of the nanostructure related to animal cell line was determined based on MTT assay., Results: In general, the synthesized core/shell nanostructure can demonstrate noticeable activity against the evaluated representative microorganisms while its toxicity against animal cell line is not considerable., Conclusion: This nanostructure can be applied as a smart drug delivery system with the help of an external magnetic field or it can be used as a powerful antibiotic agent along with other antibiotics that can form a shell on its structure., Competing Interests: Disclosure The authors report no conflicts of interest in this work.