1
|
Characterization of the Candida glabrata Transcription Factor CgMar1: Role in Azole Susceptibility. J Fungi (Basel) 2022; 8:jof8010061. [PMID: 35050001 PMCID: PMC8779156 DOI: 10.3390/jof8010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/03/2022] [Accepted: 01/05/2022] [Indexed: 11/18/2022] Open
Abstract
The prevalence of antifungal resistance in Candida glabrata, especially against azole drugs, results in difficult-to-treat and potentially life-threatening infections. Understanding the molecular basis of azole resistance in C. glabrata is crucial to designing more suitable therapeutic strategies. In this study, the role of the transcription factor encoded by ORF CAGL0B03421g, here denominated as CgMar1 (Multiple Azole Resistance 1), in azole susceptibility was explored. Using RNA-sequencing, CgMar1 was found to regulate 337 genes under fluconazole stress, including several related to lipid biosynthesis pathways. In this context, CgMar1 and its target CgRSB1, encoding a predicted sphingoid long-chain base efflux transporter, were found to contribute to plasma membrane sphingolipid incorporation and membrane permeability, decreasing fluconazole accumulation. CgMar1 was found to associate with the promoter of CgRSB1, which contains two instances of the CCCCTCC consensus, found to be required for CgRSB1 activation during fluconazole stress. Altogether, a regulatory pathway modulating azole susceptibility in C. glabrata is proposed, resulting from what appears to be a neofunctionalization of a Hap1-like transcription factor.
Collapse
|
2
|
Ribeiro GF, Denes E, Heaney H, Childers DS. What 'Omics Can Tell Us About Antifungal Adaptation. FEMS Yeast Res 2021; 21:6484793. [PMID: 34958354 PMCID: PMC8755904 DOI: 10.1093/femsyr/foab070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/22/2021] [Indexed: 12/01/2022] Open
Abstract
Invasive candidiasis, the most frequent healthcare-associated invasive fungal infection, is commonly caused by Candida albicans. However, in recent years other antifungal-resistant Candida species—namely Candida glabrata and Candidaauris—have emerged as a serious matter of concern. Much of our understanding of the mechanisms regulating antifungal resistance and tolerance relies on studies utilizing C. albicans, C. glabrataand the model yeast Saccharomyces cerevisiae. ‘Omics studies have been used to describe alterations in metabolic, genomic and transcriptomic expression profiles upon antifungal treatment of fungal cells. The physiological changes identified by these approaches could significantly affect fungal fitness in the host and survival during antifungal challenge, as well as provide further understanding of clinical resistance. Thus, this review aims to comparatively address ‘omics data for C. albicans, C. glabrata andS. cerevisiae published from 2000 to 2021 to identify what these technologies can tell us regarding cellular responses to antifungal therapy. We will also highlight possible effects on pathogen survival and identify future avenues for antifungal research.
Collapse
Affiliation(s)
- Gabriela Fior Ribeiro
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Eszter Denes
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Helen Heaney
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Delma S Childers
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| |
Collapse
|
3
|
Kaddah S, Khreich N, Kaddah F, Charcosset C, Greige-Gerges H. Pentacyclic triterpenes modulate liposome membrane fluidity and permeability depending on membrane cholesterol content. Int J Pharm 2021; 610:121232. [PMID: 34744000 DOI: 10.1016/j.ijpharm.2021.121232] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/05/2021] [Accepted: 10/23/2021] [Indexed: 12/08/2022]
Abstract
Since the membrane-related processes represent an integral part of the biological activities of drugs, their effect on the membrane dynamics is actually considered. In this study, we investigated the effect of pentacyclic triterpenes (TTPs), oleanolic acid (OA) and erythrodiol (ER), on the fluidity and permeability of liposomes membranes differing by their cholesterol content. All liposomes were prepared by reverse phase evaporation technique (REV). Spin-labeled liposomes exposed or not to TTPs were used for fluidity studies by using 5- and 16-doxyl stearic acids (DSA). TTPs-loaded liposomes (phospholipid:cholesterol of 1:1), and preformed vesicles exposed to TTPs were used for permeability studies by monitoring the release of sulforhodamine B (SRB) at 37 °C. The apparent release constants of SRB were determined by Higuchi model based on a biphasic curve shape (0-10 h; 10-48 h). TTPs-loaded liposomes were characterized for their size and homogeneity. Results showed that ER increased the membrane fluidity at the upper region of the membrane while the both TTPs produced a condensing effect at the deeper region of the membrane. The membrane composition was a critical parameter modulating the effect of TTPs on the membrane permeability. Also, this study consolidated the fact that a fluidizing membrane agent is not necessarily a permeabilizing-membrane compound.
Collapse
Affiliation(s)
- Samar Kaddah
- Bioactive Molecules Research Laboratory, Faculty of Sciences, Lebanese University, Lebanon; Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, France
| | - Nathalie Khreich
- Bioactive Molecules Research Laboratory, Faculty of Sciences, Lebanese University, Lebanon
| | - Fouad Kaddah
- École Supérieure d'ingénieurs de Beyrouth, Université Saint Joseph, Beyrouth, Mar Roukoz-Dekwaneh, Lebanon
| | | | - Hélène Greige-Gerges
- Bioactive Molecules Research Laboratory, Faculty of Sciences, Lebanese University, Lebanon.
| |
Collapse
|
4
|
Tonyali B, McDaniel A, Trinetta V, Yucel U. Evaluation of heating effects on the morphology and membrane structure of Escherichia coli using electron paramagnetic resonance spectroscopy. Biophys Chem 2019; 252:106191. [PMID: 31177024 DOI: 10.1016/j.bpc.2019.106191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/20/2019] [Accepted: 05/22/2019] [Indexed: 01/14/2023]
Abstract
Bacterial cell characteristics, such as size, morphology, and membrane integrity, are affected by environmental conditions. Thermal treatment results in related structural changes, extent of which is determined by the microorganism's survival skills and inactivation kinetics. The objective of this study was to characterize changes in cell structure of Escherichia coli during heating using the combined analysis of dynamic light scattering (DLS), electron paramagnetic resonance (EPR) spectroscopy, and transmission electron microscopy (TEM) techniques. The size of E. coli cells increased from 2.3 μm to 3.0 μm with heating up to 50 °C followed by a shrinkage with further heating up to 70 °C. The morphological changes were verified using transmission electron microscopy. Related changes in membrane integrity was quantified via the mobility of 16-doxylstearic acid (16-DSA) spin probe using EPR spectroscopy. Two order parameters S1 and S2 defined on x- and y-axes, respectively, decreased with increasing temperature indicating loss of membrane integrity. The combined techniques as in this study can be used to further understand factors that play role in survival behavior of microorganisms.
Collapse
Affiliation(s)
- Bade Tonyali
- Food Science Institute, Kansas State University, Manhattan, KS 66506, United States of America
| | - Austin McDaniel
- Food Science Institute, Kansas State University, Manhattan, KS 66506, United States of America
| | - Valentina Trinetta
- Food Science Institute, Kansas State University, Manhattan, KS 66506, United States of America; Animal Sciences and Industry, Kansas State University, Manhattan, KS 66506, United States of America
| | - Umut Yucel
- Food Science Institute, Kansas State University, Manhattan, KS 66506, United States of America; Animal Sciences and Industry, Kansas State University, Manhattan, KS 66506, United States of America.
| |
Collapse
|
5
|
Hokken MWJ, Zoll J, Coolen JPM, Zwaan BJ, Verweij PE, Melchers WJG. Phenotypic plasticity and the evolution of azole resistance in Aspergillus fumigatus; an expression profile of clinical isolates upon exposure to itraconazole. BMC Genomics 2019; 20:28. [PMID: 30626317 PMCID: PMC6327609 DOI: 10.1186/s12864-018-5255-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 11/15/2018] [Indexed: 01/26/2023] Open
Abstract
Background The prevalence of azole resistance in clinical and environmental Aspergillus fumigatus isolates is rising over the past decades, but the molecular basis of the development of antifungal drug resistance is not well understood. This study focuses on the role of phenotypic plasticity in the evolution of azole resistance in A. fumigatus. When A. fumigatus is challenged with a new stressful environment, phenotypic plasticity may allow A. fumigatus to adjust their physiology to still enable growth and reproduction, therefore allowing the establishment of genetic adaptations through natural selection on the available variation in the mutational and recombinational gene pool. To investigate these short-term physiological adaptations, we conducted time series transcriptome analyses on three clinical A. fumigatus isolates, during incubation with itraconazole. Results After analysis of expression patterns, we identified 3955, 3430, 1207, and 1101 differentially expressed genes (DEGs), after 30, 60, 120 and 240 min of incubation with itraconazole, respectively. We explored the general functions in these gene groups and we identified 186 genes that were differentially expressed during the whole time series. Additionally, we investigated expression patterns of potential novel drug-efflux transporters, genes involved in ergosterol and phospholipid biosynthesis, and the known MAPK proteins of A. fumigatus. Conclusions Our data suggests that A. fumigatus adjusts its transcriptome quickly within 60 min of exposure to itraconazole. Further investigation of these short-term adaptive phenotypic plasticity mechanisms might enable us to understand how the direct response of A. fumigatus to itraconazole promotes survival of the fungus in the patient, before any “hard-wired” genetic mutations arise. Electronic supplementary material The online version of this article (10.1186/s12864-018-5255-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Margriet W J Hokken
- Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA, Nijmegen, the Netherlands. .,Center of Expertise in Mycology Radboudumc/CWZ, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, the Netherlands.
| | - Jan Zoll
- Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA, Nijmegen, the Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, the Netherlands
| | - Jordy P M Coolen
- Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA, Nijmegen, the Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, the Netherlands
| | - Bas J Zwaan
- Department of Plant Sciences, Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708PB, Wageningen, The Netherlands
| | - Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA, Nijmegen, the Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, the Netherlands
| | - Willem J G Melchers
- Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA, Nijmegen, the Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, the Netherlands
| |
Collapse
|
6
|
Işık A, Acar Çevik U, Sağlık BN, Özkay Y. Synthesis, Characterization, and Molecular Docking Study of Some Novel Imidazole Derivatives as Potential Antifungal Agents. J Heterocycl Chem 2018. [DOI: 10.1002/jhet.3388] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Ayşen Işık
- Department of Pharmaceutical Chemistry, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
| | - Ulviye Acar Çevik
- Department of Pharmaceutical Chemistry, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
- Doping and Narcotic Compounds Analysis Laboratory, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
| | - Begüm Nurpelin Sağlık
- Department of Pharmaceutical Chemistry, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
- Doping and Narcotic Compounds Analysis Laboratory, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
| | - Yusuf Özkay
- Department of Pharmaceutical Chemistry, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
- Doping and Narcotic Compounds Analysis Laboratory, Faculty of PharmacyAnadolu University 26470 Eskişehir Turkey
| |
Collapse
|
7
|
Junior EFC, Guimarães CFRC, Franco LL, Alves RJ, Kato KC, Martins HR, de Souza Filho JD, Bemquerer MP, Munhoz VHO, Resende JM, Verly RM. Glycotriazole-peptides derived from the peptide HSP1: synergistic effect of triazole and saccharide rings on the antifungal activity. Amino Acids 2017; 49:1389-1400. [PMID: 28573520 DOI: 10.1007/s00726-017-2441-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 05/22/2017] [Indexed: 12/21/2022]
Abstract
This work proposes a strategy that uses solid-phase peptide synthesis associated with copper(I)-catalyzed azide alkyne cycloaddition reaction to promote the glycosylation of an antimicrobial peptide (HSP1) containing a carboxyamidated C-terminus (HSP1-NH2). Two glycotriazole-peptides, namely [p-Glc-trz-G1]HSP1-NH2 and [p-GlcNAc-trz-G1]HSP1-NH2, were prepared using per-O-acetylated azide derivatives of glucose and N-acetylglucosamine in the presence of copper(II) sulfate pentahydrate (CuSO4·5H2O) and sodium ascorbate as a reducing agent. In order to investigate the synergistic action of the carbohydrate motif linked to the triazole-peptide structure, a triazole derivative [trz-G1]HSP1-NH2 was also prepared. A set of biophysical approaches such as DLS, Zeta Potential, SPR and carboxyfluorescein leakage from phospholipid vesicles confirmed higher membrane disruption and lytic activities as well as stronger peptide-LUVs interactions for the glycotriazole-peptides when compared to HSP1-NH2 and to its triazole derivative, which is in accordance with the performed biological assays: whereas HSP1-NH2 presents relatively low and [trz-G1]HSP1-NH2 just moderate fungicidal activity, the glycotriazole-peptides are significantly more effective antifungal agents. In addition, the glycotriazole-peptides and the triazole derivative present strong inhibition effects on ergosterol biosynthesis in Candida albicans, when compared to HSP1-NH2 alone. In conclusion, the increased fungicidal activity of the glycotriazole-peptides seems to be the result of (A) more pronounced membrane-disruptive properties, which is related to the presence of a saccharide ring, together with (B) the inhibition of ergosterol biosynthesis, which seems to be related to the presence of both the monosaccharide and the triazole rings.
Collapse
Affiliation(s)
- Eduardo F C Junior
- Departamento de Química, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Carlos F R C Guimarães
- Departamento de Química, Universidade Federal de Minas Gerais, PO Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Lucas L Franco
- Faculdade de Farmácia, Universidade Federal de Minas Gerais, PO Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Ricardo J Alves
- Faculdade de Farmácia, Universidade Federal de Minas Gerais, PO Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Kelly C Kato
- Faculdade de Farmácia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Helen R Martins
- Faculdade de Farmácia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - José D de Souza Filho
- Departamento de Química, Universidade Federal de Minas Gerais, PO Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Marcelo P Bemquerer
- Laboratório de Espectrometria de Massa, Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)-Recursos Genéticos e Biotecnologia, Estação Parque Biológico, Final W5, Asa Norte, Brasília, DF, 70770-900, Brazil
| | - Victor H O Munhoz
- Instituto de Ciência e Tecnologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Jarbas M Resende
- Departamento de Química, Universidade Federal de Minas Gerais, PO Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Rodrigo M Verly
- Departamento de Química, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil.
| |
Collapse
|
8
|
Lv QZ, Yan L, Jiang YY. The synthesis, regulation, and functions of sterols in Candida albicans: Well-known but still lots to learn. Virulence 2016; 7:649-59. [PMID: 27221657 DOI: 10.1080/21505594.2016.1188236] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Sterols are the basal components of the membranes of the fungal pathogen Candida albicans, and these membranes determine the susceptibility of C. albicans cells to a variety of stresses, such as ionic, osmotic and oxidative pressures, and treatment with antifungal drugs. The common antifungal azoles in clinical use are targeted to the biosynthesis of ergosterol. In the past years, the synthesis, storage and metabolism of ergosterol in Saccharomyces cerevisiae has been characterized in some detail; however, these processes has not been as well investigated in the human opportunistic pathogen C. albicans. In this review, we summarize the genes involved in ergosterol synthesis and regulation in C. albicans. As well, genes in S. cerevisiae implicated in ergosterol storage and conversions with other lipids are noted, as these provide us clues and directions for the study of the homologous genes in C. albicans. In this report we have particularly focused on the essential roles of ergosterol in the dynamic process of cell biology and its fundamental status in the biological membrane system that includes lipid rafts, lipid droplets, vacuoles and mitochondria. We believe that a thorough understanding of this classic and essential pathway will give us new ideas about drug resistance and morphological switching in C. albicans.
Collapse
Affiliation(s)
- Quan-Zhen Lv
- a Center for New Drug Research, College of Pharmacy, Second Military Medical University , Shanghai , P.R. China
| | - Lan Yan
- a Center for New Drug Research, College of Pharmacy, Second Military Medical University , Shanghai , P.R. China
| | - Yuan-Ying Jiang
- a Center for New Drug Research, College of Pharmacy, Second Military Medical University , Shanghai , P.R. China
| |
Collapse
|
9
|
Ahmad A, Wani MY, Khan A, Manzoor N, Molepo J. Synergistic Interactions of Eugenol-tosylate and Its Congeners with Fluconazole against Candida albicans. PLoS One 2015; 10:e0145053. [PMID: 26694966 PMCID: PMC4980062 DOI: 10.1371/journal.pone.0145053] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 11/29/2015] [Indexed: 01/30/2023] Open
Abstract
We previously reported the antifungal properties of a monoterpene phenol “Eugenol” against different Candida strains and have observed that the addition of methyl group to eugenol drastically increased its antimicrobial potency. Based on the results and the importance of medicinal synthetic chemistry, we synthesized eugenol-tosylate and its congeners (E1-E6) and tested their antifungal activity against different clinical fluconazole (FLC)- susceptible and FLC- resistant C. albicans isolates alone and in combination with FLC by determining fractional inhibitory concentration indices (FICIs) and isobolograms calculated from microdilution assays. Minimum inhibitory concentration (MIC) results confirmed that all the tested C. albicans strains were variably susceptible to the semi-synthetic derivatives E1-E6, with MIC values ranging from 1–62 μg/ml. The test compounds in combination with FLC exhibited either synergy (36%), additive (41%) or indifferent (23%) interactions, however, no antagonistic interactions were observed. The MICs of FLC decreased 2–9 fold when used in combination with the test compounds. Like their precursor eugenol, all the derivatives showed significant impairment of ergosterol biosynthesis in all C. albicans strains coupled with down regulation of the important ergosterol biosynthesis pathway gene-ERG11. The results were further validated by docking studies, which revealed that the inhibitors snugly fitting the active site of the target enzyme, mimicking fluconazole, may well explain their excellent inhibitory activity. Our results suggest that these compounds have a great potential as antifungals, which can be used as chemosensitizing agents with the known antifungal drugs.
Collapse
Affiliation(s)
- Aijaz Ahmad
- Department of Oral Biological Sciences, School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, South Africa
| | - Mohmmad Younus Wani
- Departmento de Quimica, FCTUC, Universidade de Coimbra, Rua Larga, Coimbra, Portugal
| | - Amber Khan
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, South Africa
| | - Nikhat Manzoor
- College of Applied Medical Sciences, Taibah University, Al-Madinah Al-Munawarah, KSA
- Department of Biosciences, Jamia Millia Islamia, New Delhi, Delhi, India
- * E-mail: (JM); (NM)
| | - Julitha Molepo
- Department of Oral Biological Sciences, School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, South Africa
- * E-mail: (JM); (NM)
| |
Collapse
|
10
|
Wani MY, Ahmad A, Shiekh RA, Al-Ghamdi KJ, Sobral AJFN. Imidazole clubbed 1,3,4-oxadiazole derivatives as potential antifungal agents. Bioorg Med Chem 2015; 23:4172-4180. [PMID: 26164624 DOI: 10.1016/j.bmc.2015.06.053] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/18/2015] [Accepted: 06/20/2015] [Indexed: 11/25/2022]
Abstract
A series of compounds in which 2-(4-ethyl-2-pyridyl)-1H-imidazole was clubbed with substituted 1,3,4-oxadiazole was synthesized and subjected to antifungal activity evaluation. In vitro assays indicated that several clubbed derivatives had excellent antifungal activity against different strains of laboratory and clinically isolated Candida species. Structural Activity Relationship (SAR) studies revealed that the presence and position of substituents on the phenyl ring of the 1,3,4-oxadiazole unit, guides the antifungal potential of the compounds, where compound 4b, 4c and 4g were found to be active against all the tested fungal strains. Impairment of ergosterol biosynthesis upon the concomitant treatment of 4b, 4c and 4g, revealed the possible mechanisms of antifungal action of these compounds. Inhibitors snugly fitting the active site of the target enzyme, as revealed by molecular docking studies, may well explain their excellent inhibitory activity.
Collapse
Affiliation(s)
- Mohmmad Younus Wani
- Departmento de Quimica, FCTUC, Universidade de Coimbra, Rua Larga, Coimbra 3004-535, Portugal.
| | - Aijaz Ahmad
- Department of Oral Biological Sciences, University of Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
| | - Rayees Ahmad Shiekh
- Department of Chemistry, Faculty of Science, Taibah University, PO Box 30002, Al Madinah Al Munawarrah, Saudi Arabia
| | - Khalaf J Al-Ghamdi
- Department of Chemistry, Faculty of Science, Taibah University, PO Box 30002, Al Madinah Al Munawarrah, Saudi Arabia
| | - Abilio J F N Sobral
- Departmento de Quimica, FCTUC, Universidade de Coimbra, Rua Larga, Coimbra 3004-535, Portugal.
| |
Collapse
|
11
|
Antimicrobial and Antibiofilm Activity of Chitosan on the Oral Pathogen Candida albicans. Pathogens 2014; 3:908-19. [PMID: 25513734 PMCID: PMC4282891 DOI: 10.3390/pathogens3040908] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/03/2014] [Accepted: 12/04/2014] [Indexed: 11/28/2022] Open
Abstract
Oral candidiasis is particularly evident, not only in cancer patients receiving chemotherapy, but also in elderly people with xerostomy. In general, Candida is an opportunistic pathogen, causing infections in immunocompromised people and, in some cases, when the natural microbiota is altered. Chitosan, a natural derivative of chitin, is a polysaccharide that has been proven to possess a broad spectrum of antimicrobial activity that encompasses action against fungi, yeast and bacteria. While recent studies have revealed a significant antibiofilm activity upon several microorganisms, including C. albicans, little is known regarding the impact of chitosan upon the adhesive process or mature biofilms. With that in mind, the purpose of this work was to evaluate, in vitro, the capability of chitosan to inhibit C. albicans growth and biofilm formation. The results obtained showed that chitosan is capable of inhibiting C. albicans planktonic growth (HMW, 1 mg/mL; LMW, 3 mg/mL). Regarding biofilm growth, chitosan inhibited C. albicans adhesion (ca. 95%), biofilm formation (percentages above 90%) and reduced mature biofilms by ca. 65% and dual species biofilms (C. albicans and S. mutans) by ca. 70%. These results display the potential of this molecule to be used as an effective anti-Candida agent capable of acting upon C. albicans infections.
Collapse
|