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Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms
BACKGROUND: Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment. The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ(24(25))-sterol methyltran...
Autores principales: | , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2009
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2679025/ https://www.ncbi.nlm.nih.gov/pubmed/19379501 http://dx.doi.org/10.1186/1471-2180-9-74 |
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author | Ishida, Kelly Rodrigues, Juliany Cola Fernandes Ribeiro, Marcos Dornelas Vila, Taíssa Vieira Machado de Souza, Wanderley Urbina, Julio A Nakamura, Celso Vataru Rozental, Sonia |
author_facet | Ishida, Kelly Rodrigues, Juliany Cola Fernandes Ribeiro, Marcos Dornelas Vila, Taíssa Vieira Machado de Souza, Wanderley Urbina, Julio A Nakamura, Celso Vataru Rozental, Sonia |
author_sort | Ishida, Kelly |
collection | PubMed |
description | BACKGROUND: Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment. The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ(24(25))-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5α-pregnan-3β-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of Candida spp., analysing the ultrastructural changes. RESULTS: AZA and EIL were found to be potent growth inhibitors of Candida spp. isolates. The median MIC(50 )was 0.5 μg.ml(-1 )for AZA and 2 μg.ml(-1 )for EIL, and the MIC(90 )was 2 μg.ml(-1 )for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were Candida non-albicans (CNA) species, but several of them, such as C. guilliermondii, C. zeylanoides, and C. lipolytica, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain C. krusei (ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay. CONCLUSION: Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control Candida spp. infections, including those caused by azole-resistant strains. |
format | Text |
id | pubmed-2679025 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2009 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-26790252009-05-08 Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms Ishida, Kelly Rodrigues, Juliany Cola Fernandes Ribeiro, Marcos Dornelas Vila, Taíssa Vieira Machado de Souza, Wanderley Urbina, Julio A Nakamura, Celso Vataru Rozental, Sonia BMC Microbiol Research article BACKGROUND: Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment. The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ(24(25))-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5α-pregnan-3β-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of Candida spp., analysing the ultrastructural changes. RESULTS: AZA and EIL were found to be potent growth inhibitors of Candida spp. isolates. The median MIC(50 )was 0.5 μg.ml(-1 )for AZA and 2 μg.ml(-1 )for EIL, and the MIC(90 )was 2 μg.ml(-1 )for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were Candida non-albicans (CNA) species, but several of them, such as C. guilliermondii, C. zeylanoides, and C. lipolytica, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain C. krusei (ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay. CONCLUSION: Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control Candida spp. infections, including those caused by azole-resistant strains. BioMed Central 2009-04-20 /pmc/articles/PMC2679025/ /pubmed/19379501 http://dx.doi.org/10.1186/1471-2180-9-74 Text en Copyright ©2009 Ishida et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research article Ishida, Kelly Rodrigues, Juliany Cola Fernandes Ribeiro, Marcos Dornelas Vila, Taíssa Vieira Machado de Souza, Wanderley Urbina, Julio A Nakamura, Celso Vataru Rozental, Sonia Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms |
title | Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms |
title_full | Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms |
title_fullStr | Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms |
title_full_unstemmed | Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms |
title_short | Growth inhibition and ultrastructural alterations induced by Δ(24(25))-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms |
title_sort | growth inhibition and ultrastructural alterations induced by δ(24(25))-sterol methyltransferase inhibitors in candida spp. isolates, including non-albicans organisms |
topic | Research article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2679025/ https://www.ncbi.nlm.nih.gov/pubmed/19379501 http://dx.doi.org/10.1186/1471-2180-9-74 |
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