Showing 5 results for Nikoomanesh
Volume 2, Issue 1 (1-2016)
Abstract
Background: Adhesion and biofilm formation are two important steps in Candida pathogenesis. The aim of the current study was to investigate the presence of bcr1 gene in Candida albicans (C. albicans) isolates from women with vaginal candidiasis and its impact on biofilm formation. Methods: We used 50 clinical isolates which confirmed C. albicans by PCR-RFLP. Then total RNA was extracted from C. albicans isolates by glass bead and lysis buffer, and cDNA was synthesized using reverse transcriptase enzyme. RT-PCR (Reverse Transcriptase PCR) was used to evaluate the expression of bcr1 gene. Biofilm formation was evaluated in 96-well microplate and then tetrazolium reduction was assayed. All data were analyzed using t-test by SPSS software. Results: Fifty clinical isolates out of 150 were confirmed as C. albicans by using PCR-RFLP method. All the isolates were resistant to fluconazole, 47/50(94%) isolates had bcr1 gene by using PCR, and 45(95.7%) out of 47 isolates, showed BCR1 expression by the RT-PCR. Isolates which harbored bcr1 gene was succeed to form a dense biofilm on microplate. Comparison of the results of the tetrazolium reduction assay on the two isolates that had BCR1expression and two isolates that had no BCR1 expression showed significant differences (p=0.014). Conclusion: According to our result, all of the isolates that had bcr1 gene expression according to RT-PCR, were also resistant to fluconazole in disk diffusion test and additionally, their adherence was higher compared to the control group. These results indicate that there is a positive relation between expression of bcr1 gene and biofilm formation.
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.
Volume 7, Issue 3 (Summer 2021)
Abstract
Backgrounds: Due to the emergence of multidrug-resistant Candida species, the discovery of new antifungal agents with minimum side effects is essential. The aim of this study was to investigate the antifungal activity of caprylic acid and nano-encapsulated caprylic acid against C. albicans as well as their effect on the expression of EFG1 gene.
Materials & Methods: In this laboratory trial study, the minimum inhibitory concentration (MIC) of caprylic acid and nano-encapsulated caprylic acid against C. albicans was evaluated at various concentrations (400-625 and 1.3-50 μL/mL, respectively). Real time-PCR was performed to assess the expression level of EFG1 gene. Cytotoxicity effect of caprylic acid and nano-encapsulated caprylic acid was evaluated on SW480 cell line using MTT test.
Findings: Antifungal activity findings displayed that MIC90 and MIC50 values of caprylic acid were 500 and 450 μg/mL, respectively, whereas MIC90 and MIC50 values of nano-encapsulated caprylic acid were 6.2 and 3.1 μg/mL, respectively. The expression of EFG1 gene significantly decreased in the groups treated with caprylic acid and nano-encapsulated caprylic acid compared to the control group. According to the cytotoxicity evaluation findings, the viability of cells treated with caprylic acid was significantly higher than that of cells exposed to nano-encapsulated caprylic acid.
Conclusions: According to the obtained results, nano-encapsulated caprylic acid successfully inhibited C. albicans growth at a lower concentration compared to caprylic acid. Overall, it was found that nano-encapsulated caprylic acid is a promising antifungal agent against Candida species; however, further studies are needed to be performed about nano-encapsulation of caprylic acid.
Volume 8, Issue 4 (fall 2022)
Abstract
Backgrounds: In this research, an attempt was made to identify Candida isolates collected from women with suspected vulvovaginal candidiasis using single Multiplex PCR reaction as a swift and valid method. Beside, this method was compared with phenotypic methods.
Materials & Methods: In this study, 250 vaginal swabs were collected from patients referring to obstetrics and gynecology specialists. In addition to phenotypic methods, multiplex PCR designed by species-specific primers was performed to identify Candida isolates in a single reaction. Descriptive statistics were analyzed by t-test and Chi-square test in SPSS software (Ver. 22) (p< .05).
Findings: According to the results, 92 positive samples were diagnosed using the culture method. Four species were identified by culturing the specimens on CHROM agar. The most common Candida species isolated was C. albicans (54.3%), followed by C. parapsilosis (28.2%), C. glabrata (17.4%), and C. krusei (1.0%). The most common Candida spp. identified by Multiplex PCR method were C. albicans (50.0%), C. glabrata (33.7%), and C. parapsilosis (6.2%). Also, three mixed infections with C. albicans and C. glabrata as well as C. albicans and C. parapsilosis were identified
Conclusion: In comparison to phenotypic methods, considering the cost-effectiveness of PCR methods, the single multiplex PCR reaction was shown to be efficient in epidemiological studies on pathogenic species.
