Aims This study aimed to investigate the mechanism of antifungal action of Streptomyces libani dichloromethane extract fraction A (DCEFA) against Aspergillus fumigatus and the host cytotoxicity. Methods and Results DCEFA was purified from S. libani by autobiography and showed strong antifungal activity against A. fumigatus. A combination of electron microscopy, cell permeability assays, total oxidant status (TOS) assay, cell cytotoxicity assay, and hemolysis activity were carried out to determine the target site of DCEFA. Exposure of A. fumigatus to DCEFA caused the damage to membranous cellular structures and increased release of cellular materials, potassium ions and TOS production. DCEFA was bound to ergosterol but did not affect fun

Cryptococcosis is an opportunistic fungal infection caused mainly by Cryptococcus neoformans. The aim of the present study was to evaluate the inhibitory effect of aureobasidin A on C. neoformans with special focus on its mode of action. The effect of aureobasidin A on cell membrane ergosterol content, cell wall permeability, membrane pumps activities, the total oxidant status (TOS) and melanin production was evaluated. Cytotoxicity and cell hemolysis, and laccase (LacI) and β1,2-xylosyltransferase (Cxt1p) gene expression were also evaluated. Aureobasidin A reduced melanin production and increased extracellular potassium leakage at 0.5?MIC concentration. This peptide has no effect on fungal cell wall integrity. Cell membrane ergosterol con

Fungal species resistant to current antifungal agents are considered as a serious threat to human health; the dilemma that has dragged attentions toward other sources of antifungals such as antimicrobial peptides (AMPs). In order to improve biological activity of a recently described antifungal peptide MCh-AMP1 from Matricaria chamomilla flowers, MCh-AMP1dimer (DiMCh-AMP1), containing 61 amino acid residues connected by flexible linker (GPDGSGPDESGPDES) was designed, expressed in Escherichia coli and its structure was analyzed using bioinformatics tools. DiMCh-AMP1 synthetic gene was cloned into pET-28a expression vector, which was then used to transform E. coli BL21 (DE3) strain. His-tag purification was achieved using metal-chelate affini

Design, Dimerization, and Recombinant Production of MCh-AMP1–Derived Peptide in Escherichia coli and Evaluation of Its Antifun

Background- Dermatophytes are a homogeneous group of species with low genetic diversity and there are still many uncertainties about the boundaries among species. Objectives- Aiming at clarifying the relationships among species in the genus and introducing suitable genes for multilocus sequence typing (MLST), a new MLST scheme approach was developed to characterize the major pathogenic dermatophytes. Methods- We performed maximum parsimony, MrBayes, RAxML, and eBURST analyses, based on the MLST scheme to scrutinize the evolution within 95 clinical isolates and 4 reference strains belonging to the four major dermatophytes species. Then, the discriminatory power, pairwise genetic distances, ratio dN/dS, and sequence types (STs) of these isola

Objective: Precise identification of dermatophyte species significantly improves treatment and controls measures of dermatophytosis in human and animals. This study was designed to evaluate molecular tools effectiveness of the gene sequencing and DNA-based fragment polymorphism analysis for accurate identification and differentiation of closelyrelated dermatophyte species isolated from clinical cases of dermatophytosis and their antifungal susceptibility to the current antifungal agents. Materials and Methods: In this experimental study, a total of 95 skin samples were inoculated into mycobiotic agar for two weeks at 28 C. Morphological characteristics of the isolated dermatophytes were evaluated. DNA was extracted from the fungal culture f

Materials and Methods: For the purpose of the study, the growth, urease, synergism activity, and disk diffusion of C. neoformans were assessed in eugenol-treated culture. The minimum inhibitory concentration (MIC) was determined by the Clinical and Laboratory Standards Institute M27-A3 method at a concentration range of 0.062-2 mg/mL. Subsequently, the expression of Cxt1p genes was studied at the MIC50 concentration of eugenol using real-time polymerase chain reaction. Results: The obtained results showed that eugenol at the concentrations of 125 and 500 ?g/mL resulted in 50% and 100% growth inhibition in C. neoformans, respectively. In terms of urease activity, the results showed that the addition of MIC50 of eugenol and fluconazole to ure

Background: The Candida albicans is one of the most important global opportunistic pathogens, and the incidence of candidiasis has increased over the past few decades. Despite the established role of skin in defense against fungal invasion, little has been documented about the pathogenesis of Candida species when changing from normal flora to pathogens of vaginal and gastrointestinal epithelia. This study was carried out to determine in vivo and in vitro pathogenesis of clinical C. albicans strains isolated from skin lesions Methods: In this study, association of in vivo and in vitro pathogenesis of C. albicans isolates with different evolutionary origins was investigated. Oral and systemic experimental candidiasis was established in BALB/C

Background and Purpose: The present study was conducted to investigate the inhibitory effects of Carum carvi essential oil (EO) against ERG6 gene expression in relation to fungal growth and some important virulence factors in Candida albicans.Materials and Methods: The minimum inhibitory concentration (MIC) of C. carvi EO against C. albicans was determined by the Clinical and Laboratory Standards Institute M27-A4 method at a concentration range of 20-1280 μg/ml. Furthermore, the expression of ERG6 gene was studied at the 0.5? MIC concentration of C. carvi EO using real-time polymerase chain reaction. The proteinase and phospholipase activities, cell surface hydrophobicity (CSH), and cell membrane ergosterol (CME) content of C. albicans wer

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Background: It is estimated that more than 80% of cases of human infections are related to biofilm formation by invasive bacteria. So, in this study, we considered the activity of cellobiose dehydrogenase enzyme (CDH) isolated from Aspergillus niger, as an antibiofilm agent, on biofilm of clinical Staphylococcus epidermidis and Pseudomonas aeruginosa isolates. Methods: In this study, five standard strains of Aspergillus niger were purchased for CDH production. Of the 42 isolated bacterial strains, 24 strains were Staphylococcus epidermidis and 18 strains were Pseudomonas aeruginosa. Zymogram method was used for screening of CDH. The CDH activity was measured by monitoring the decrease in absorbance of 2, 6-dichlorophenolindophenol (DCPIP) s

Abstract Background and Objectives: Soil bacteria have extreme population diversity among natural sources and are able to produce a wide array of antifungal metabolites. This study aimed toisolate and identifythebioactive metabolite-producing bacteria from forest soils and evaluate their antimicrobial potent against some pathogenic organisms. Materials and Methods:In this study, soil samples werescreened?for antifungal activity against?Aspergillus fumigatuson glucose-yeast extract (GY) agar using a visual agar plate assay method. All growing bacteria were examined for antifungal activity, and antagonistic bacteria were identified based on 16S ribosomal RNA sequence analysis. For optimization ofthe production of antifungal bioactive metaboli