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Showing 2 results for Bashardoust
Volume 2, Issue 3 (7-2016)
Abstract
Background: This study was performed to determine antifungal activity of silver nanoparticles (nano-Ag) compared to voriconazole on clinical and standard strains of Aspergillus fumigatus.
Materials and Methods: Inhibitory potency of nano-Ag was determined using microtiter broth dilution method. Susceptibility tests were performed against A. fumigatus isolated from BAL (bronchoalveolar lavage) of patients who suffered from respiratory problems and compared with the strain (ATCC: 204305) by broth dilution antifungal susceptibility test of filamentous fungi approved by the Clinical and Laboratory Standards Institute M38-A. In addition, cytotoxicity effect of silver nanoparticles was studied on epithelial cell line by MTT assay.
Results: From 60 BAL samples the following strains were isolated; A. flavus (n=21), A. niger (n=3), and A. fumigatus (n=1). The minimum inhibitory concentration (MIC90) values of nano-Ag were 0.25 and 0.5 μg.mL-1 for standard strain and clinical isolates respectively. The Minimum Fungicidal Concentration (MFC) values of nano-Ag were 0.5 and 1 μg.mL-1for standard strain and clinical isolates respectively. MIC90 values of voriconazole were 0.125 and 0.25 μg.mL-1 for standard strain and clinical isolate respectively. The MFC values of voriconazole were 0.25 and 0 μg.mL-1 for standard strain and clinical isolates respectively. Silver nanoparticles exhibited low cytotoxicity in 0.25 μg.mL-1 concentration.
Conclusion: Our results showed high antifungal activity of silver nanoparticles against Aspergillus isolates. Furthermore, the availability of a wide form of nano-Ag structures can be considered as novel agents to decrease fungal burden in medical application.
Volume 4, Issue 2 (Spring 2018)
Abstract
Aims: Candida albicans a polymorphic fungus can grow as yeast, pseudohyphae and true hyphae forms. The hyphal form has a key role in infection process during invasion to mucosal membrane. A cluster of genes contribute in controlling of hyphae formation in C. albicans, include SAP6, HWP1 and RIM101. Farnesol is a quorum sensing molecule which inhibits switching of yeast-to-hyphae form. The aim of this study was to investigate the effect of farnesol on yeast-to-hyphae morphogenesis and its related gene expressions in C. albicans.
Materials and Methods: In this laboratory trial study, C .albicans was exposed to various concentration (5, 10, 20, 50, 100, 150 and 300µM) of farnesol and the rate of yeast cell proliferations and germ tube formation was evaluated by different methods and microscopic examination. Real time-PCR was performed to assess the expression levels of the hyphae-specific genes SAP6, HWP1 and RIM101. The results were analyzed by IBM SPSS 23 software using Student's t-test and one-way ANOVA.
Findings: The yeast growth reduced 5% in 300µM of farnesol approximately (p<0.05). Germ tube formation strongly suppressed. Moreover, Real time-PCR analysis showed that 300µM farnesol decreased HWP1 and SAP6 gene expressions significantly in comparison to control group (p<0.05), whereas, there was no difference in the expression of RIM101 gene.
Conclusion: Farnesol in 300µM concentration can inhibits growth and proliferation of C. albicans yeast cells and also inhibits hyphal formation. Farnesol can affect the expression of virulent genes including pathogenic genes that are associated with hyphae morphogenesis such as SAP6 and HWP1.
