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Lipke PN. What We Do Not Know about Fungal Cell Adhesion Molecules. J Fungi (Basel) 2018; 4:jof4020059. [PMID: 29772751 PMCID: PMC6023273 DOI: 10.3390/jof4020059] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/27/2018] [Accepted: 05/10/2018] [Indexed: 12/16/2022] Open
Abstract
There has been extensive research on structure and function of fungal cell adhesion molecules, but the most of the work has been about adhesins in Candida albicans and Saccharomyces cerevisiae. These yeasts are members of a single ascomycete order, and adhesion molecules from the six other fungal phyla are only sparsely described in the literature. In these other phyla, most of the research is at the cellular level, rather than at the molecular level, so there has been little characterization of the adhesion molecules themselves. A catalog of known adhesins shows some common features: high Ser/Thr content, tandem repeats, N- and O-glycosylations, GPI anchors, dibasic sequence motifs, and potential amyloid-forming sequences. However, none of these features is universal. Known ligands include proteins and glycans on homologous cells and host cells. Existing and novel tools can exploit the availability of genome sequences to identify and characterize new fungal adhesins. These include bioinformatics tools and well-established yeast surface display models, which could be coupled with an adhesion substrate array. Thus, new knowledge could be exploited to answer key questions in fungal ecology, animal and plant pathogenesis, and roles of biofilms in infection and biomass turnover.
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Affiliation(s)
- Peter N Lipke
- Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA.
- The Graduate Center, City University of New York, New York, NY 10016, USA.
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102
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Portrait of Matrix Gene Expression in Candida glabrata Biofilms with Stress Induced by Different Drugs. Genes (Basel) 2018; 9:genes9040205. [PMID: 29642649 PMCID: PMC5924547 DOI: 10.3390/genes9040205] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/29/2018] [Accepted: 04/05/2018] [Indexed: 01/22/2023] Open
Abstract
(1) Background: Candida glabrata is one of the most significant Candida species associated with severe cases of candidiasis. Biofilm formation is an important feature, closely associated with antifungal resistance, involving alterations of gene expression or mutations, which can result in the failure of antifungal treatments. Hence, the main goal of this work was to evaluate the role of a set of genes, associated with matrix production, in the resistance of C. glabrata biofilms to antifungal drugs. (2) Methods: the determination of the expression of BGL2, XOG1, FKS1, FKS2, GAS2, KNH1, UGP1, and MNN2 genes in 48-h biofilm’s cells of three C. glabrata strains was performed through quantitative real-time PCR (RT-qPCR), after contact with Fluconazole (Flu), Amphotericin B (AmB), Caspofungin (Csf), or Micafungin (Mcf). (3) Results: Mcf induced a general overexpression of the selected genes. It was verified that the genes related to the production of β-1,3-glucans (BGL2, XOG1, GAS2) had the highest expressions. (4) Conclusion: though β-1,6-glucans and mannans are an essential part of the cell and biofilm matrix, C. glabrata biofilm cells seem to contribute more to the replacement of β-1,3-glucans. Thus, these biopolymers seem to have a greater impact on the biofilm matrix composition and, consequently, a role in the biofilm resistance to antifungal drugs.
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103
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Dominguez E, Zarnowski R, Sanchez H, Covelli AS, Westler WM, Azadi P, Nett J, Mitchell AP, Andes DR. Conservation and Divergence in the Candida Species Biofilm Matrix Mannan-Glucan Complex Structure, Function, and Genetic Control. mBio 2018; 9:e00451-18. [PMID: 29615504 PMCID: PMC5885036 DOI: 10.1128/mbio.00451-18] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 03/01/2018] [Indexed: 01/18/2023] Open
Abstract
Candida biofilms resist the effects of available antifungal therapies. Prior studies with Candida albicans biofilms show that an extracellular matrix mannan-glucan complex (MGCx) contributes to antifungal sequestration, leading to drug resistance. Here we implement biochemical, pharmacological, and genetic approaches to explore a similar mechanism of resistance for the three most common clinically encountered non-albicansCandida species (NAC). Our findings reveal that each Candida species biofilm synthesizes a mannan-glucan complex and that the antifungal-protective function of this complex is conserved. Structural similarities extended primarily to the polysaccharide backbone (α-1,6-mannan and β-1,6-glucan). Surprisingly, biochemical analysis uncovered stark differences in the branching side chains of the MGCx among the species. Consistent with the structural analysis, similarities in the genetic control of MGCx production for each Candida species also appeared limited to the synthesis of the polysaccharide backbone. Each species appears to employ a unique subset of modification enzymes for MGCx synthesis, likely accounting for the observed side chain diversity. Our results argue for the conservation of matrix function among Candida spp. While biogenesis is preserved at the level of the mannan-glucan complex backbone, divergence emerges for construction of branching side chains. Thus, the MGCx backbone represents an ideal drug target for effective pan-Candida species biofilm therapy.IMPORTANCECandida species, the most common fungal pathogens, frequently grow as a biofilm. These adherent communities tolerate extremely high concentrations of antifungal agents, due in large part, to a protective extracellular matrix. The present studies define the structural, functional, and genetic similarities and differences in the biofilm matrix from the four most common Candida species. Each species synthesizes an extracellular mannan-glucan complex (MGCx) which contributes to sequestration of antifungal drug, shielding the fungus from this external assault. Synthesis of a common polysaccharide backbone appears conserved. However, subtle structural differences in the branching side chains likely rely upon unique modification enzymes, which are species specific. Our findings identify MGCx backbone synthesis as a potential pan-Candida biofilm therapeutic target.
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Affiliation(s)
- Eddie Dominguez
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert Zarnowski
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Hiram Sanchez
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Antonio S Covelli
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - William M Westler
- National Magnetic Resonance Facility, University of Wisconsin-Madison, Wisconsin, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Jeniel Nett
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Aaron P Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - David R Andes
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Manfiolli AO, Dos Reis TF, de Assis LJ, de Castro PA, Silva LP, Hori JI, Walker LA, Munro CA, Rajendran R, Ramage G, Goldman GH. Mitogen activated protein kinases (MAPK) and protein phosphatases are involved in Aspergillus fumigatus adhesion and biofilm formation. Cell Surf 2018; 1:43-56. [PMID: 32743127 PMCID: PMC7389341 DOI: 10.1016/j.tcsw.2018.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/08/2018] [Accepted: 03/14/2018] [Indexed: 12/28/2022] Open
Abstract
The main characteristic of biofilm formation is extracellular matrix (ECM) production. The cells within the biofilm are surrounded by ECM which provides structural integrity and protection. During an infection, this protection is mainly against cells of the immune system and antifungal drugs. A. fumigatus forms biofilms during static growth on a solid substratum and in chronic aspergillosis infections. It is important to understand how, and which, A. fumigatus signal transduction pathways are important for the adhesion and biofilm formation in a host during infection. Here we investigated the role of MAP kinases and protein phosphatases in biofilm formation. The loss of the MAP kinases MpkA, MpkC and SakA had an impact on the cell surface and the ECM during biofilm formation and reduced the adherence of A. fumigatus to polystyrene and fibronectin-coated plates. The phosphatase null mutants ΔsitA and ΔptcB, involved in regulation of MpkA and SakA phosphorylation, influenced cell wall carbohydrate exposure. Moreover, we characterized the A. fumigatus protein phosphatase PphA. The ΔpphA strain was more sensitive to cell wall-damaging agents, had increased β-(1,3)-glucan and reduced chitin, decreased conidia phagocytosis by Dictyostelium discoideum and reduced adhesion and biofilm formation. Finally, ΔpphA strain was avirulent in a murine model of invasive pulmonary aspergillosis and increased the released of tumor necrosis factor alpha (TNF-α) from bone marrow derived macrophages (BMDMs). These results show that MAP kinases and phosphatases play an important role in signaling pathways that regulate the composition of the cell wall, extracellular matrix production as well as adhesion and biofilm formation in A. fumigatus.
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Affiliation(s)
- Adriana Oliveira Manfiolli
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Thaila Fernanda Dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lilian Pereira Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Juliana I Hori
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Louise A Walker
- School of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Carol A Munro
- School of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Ranjith Rajendran
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, The University of Glasgow, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - Gordon Ramage
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, The University of Glasgow, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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105
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Targeting Candida spp. to develop antifungal agents. Drug Discov Today 2018; 23:802-814. [PMID: 29353694 DOI: 10.1016/j.drudis.2018.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/09/2017] [Accepted: 01/04/2018] [Indexed: 01/15/2023]
Abstract
Invasive fungal infections are a complex challenge throughout the world because of their high incidence, mainly in critically ill patients, and high mortality rates. The antifungal agents currently available are limited; thus, there is a need for the rapid development of new drugs. In silico methods are a modern strategy to explore interactions between new compounds and specific fungal targets, but they depend on precise genetic information. Here, we discuss the main Candida spp. target genes, including information about null mutants, virulence, cytolocalization, co-regulatory genes, and compounds that are related to protein expression. These data will provide a basis for the future in silico development of antifungal drugs.
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Abstract
Microbial biofilms can colonize medical devices and human tissues, and their role in microbial pathogenesis is now well established. Not only are biofilms ubiquitous in natural and human-made environments, but they are also estimated to be associated with approximately two-thirds of nosocomial infections. This multicellular aggregated form of microbial growth confers a remarkable resistance to killing by antimicrobials and host defenses, leading biofilms to cause a wide range of subacute or chronic infections that are difficult to eradicate. We have gained tremendous knowledge on the molecular, genetic, microbiological, and biophysical processes involved in biofilm formation. These insights now shape our understanding, diagnosis, and management of many infectious diseases and direct the development of novel antimicrobial therapies that target biofilms. Bacterial and fungal biofilms play an important role in a range of diseases in pulmonary and critical care medicine, most importantly catheter-associated infections, ventilator-associated pneumonia, chronic Pseudomonas aeruginosa infections in cystic fibrosis lung disease, and Aspergillus fumigatus pulmonary infections.
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107
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Shao J, Cui Y, Zhang M, Wang T, Wu D, Wang C. Synergistic in vitro activity of sodium houttuyfonate with fluconazole against clinical Candida albicans strains under planktonic growing conditions. PHARMACEUTICAL BIOLOGY 2017; 55:355-359. [PMID: 27931143 PMCID: PMC6130526 DOI: 10.1080/13880209.2016.1237977] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 08/28/2016] [Accepted: 09/14/2016] [Indexed: 06/06/2023]
Abstract
CONTEXT Fluconazole resistance is an intractable problem of treating Candida albicans, calling for more antifungal agents to enhance the activity of fluconazole. OBJECTIVE This work investigates the anti-C. albicans activities of sodium houttuyfonate (SH) and/or fluconazole and the associated mechanism. MATERIALS AND METHODS The minimum inhibitory concentrations (MICs) of SH and fluconazole both ranging from 0.5 to 1024 μg/mL were determined by broth microdilution method in 19 C. albicans isolates, and their fractional inhibitory concentration index (FICI) was evaluated by checkerboard assay. After MICSH and/or MICfluconazole treatments, the expressions of IFD6, PHR1, ZAP1, ADH5, BGL2, XOG1 and FKS1 were analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in C. albicans 1601. RESULTS AND CONCLUSION The MICs of SH alone ranged from 32 to 256 μg/mL and decreased 2-16-fold in combination. SH showed strong synergism with fluconazole with FICI <0.13-0.5. In C. albicans 1601, we observed that (i) the expression of the seven genes increased notably in a range between 3.71- and 12.63-fold (p < 0.05) when SH was used alone, (ii) the combined use of SH and fluconazole slightly inhibited the expression of IFD6 and PHR1 by 1.23- and 1.35-fold (p > 0.05), but promoted evidently the expression of ZAP1, ADH5, XOG1 and FKS1 by 1.98-, 3.56-, 4.10- and 2.86-fold (p < 0.05). The results suggested SH to be a potential synergist to enhance the antifungal activity of fluconazole in C. albicans resistant isolates, and the underlying mechanism may be associated with β-1,3-glucan synthesis and transportation.
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Affiliation(s)
- Jing Shao
- Laboratory of Microbiology and Immunology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - YanYan Cui
- Laboratory of Microbiology and Immunology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - MengXiang Zhang
- Laboratory of Microbiology and Immunology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - TianMing Wang
- Laboratory of Biochemistry and Molecular Biology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - DaQiang Wu
- Laboratory of Microbiology and Immunology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - ChangZhong Wang
- Laboratory of Microbiology and Immunology, School of Chinese and Western Integrative Medicine, Anhui University of Chinese Medicine, Hefei, China
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Modulation of Staphylococcus aureus Response to Antimicrobials by the Candida albicans Quorum Sensing Molecule Farnesol. Antimicrob Agents Chemother 2017; 61:AAC.01573-17. [PMID: 28893777 DOI: 10.1128/aac.01573-17] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/04/2017] [Indexed: 12/11/2022] Open
Abstract
In microbial biofilms, microorganisms utilize secreted signaling chemical molecules to coordinate their collective behavior. Farnesol is a quorum sensing molecule secreted by the fungal species Candida albicans and shown to play a central physiological role during fungal biofilm growth. Our pervious in vitro and in vivo studies characterized an intricate interaction between C. albicans and the bacterial pathogen Staphylococcus aureus, as these species coexist in biofilm. In this study, we aimed to investigate the impact of farnesol on S. aureus survival, biofilm formation, and response to antimicrobials. The results demonstrated that in the presence of exogenously supplemented farnesol or farnesol secreted by C. albicans in biofilm, S. aureus exhibited significantly enhanced tolerance to antimicrobials. By using gene expression studies, S. aureus mutant strains, and chemical inhibitors, the mechanism for the enhanced tolerance was attributed to upregulation of drug efflux pumps. Importantly, we showed that sequential exposure of S. aureus to farnesol generated a phenotype of high resistance to antimicrobials. Based on the presence of intracellular reactive oxygen species upon farnesol exposure, we hypothesize that antimicrobial tolerance in S. aureus may be mediated by farnesol-induced oxidative stress triggering the upregulation of efflux pumps, as part of a general stress response system. Hence, in mixed biofilms, C. albicans may influence the pathogenicity of S. aureus through acquisition of a drug-tolerant phenotype, with important therapeutic implications. Understanding interspecies signaling in polymicrobial biofilms and the specific drug resistance responses to secreted molecules may lead to the identification of novel targets for drug development.
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Alves R, Mota S, Silva S, F Rodrigues C, P Brown AJ, Henriques M, Casal M, Paiva S. The carboxylic acid transporters Jen1 and Jen2 affect the architecture and fluconazole susceptibility of Candida albicans biofilm in the presence of lactate. BIOFOULING 2017; 33:943-954. [PMID: 29094611 DOI: 10.1080/08927014.2017.1392514] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/10/2017] [Indexed: 06/07/2023]
Abstract
Candida albicans has the ability to adapt to different host niches, often glucose-limited but rich in alternative carbon sources. In these glucose-poor microenvironments, this pathogen expresses JEN1 and JEN2 genes, encoding carboxylate transporters, which are important in the early stages of infection. This work investigated how host microenvironments, in particular acidic containing lactic acid, affect C. albicans biofilm formation and antifungal drug resistance. Multiple components of the extracellular matrix were also analysed, including their impact on antifungal drug resistance, and the involvement of both Jen1 and Jen2 in this process. The results show that growth on lactate affects biofilm formation, morphology and susceptibility to fluconazole and that both Jen1 and Jen2 might play a role in these processes. These results support the view that the adaptation of Candida cells to the carbon source present in the host niches affects their pathogenicity.
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Affiliation(s)
- Rosana Alves
- a Centre of Molecular and Environmental Biology, Department of Biology , University of Minho , Braga , Portugal
| | - Sandra Mota
- a Centre of Molecular and Environmental Biology, Department of Biology , University of Minho , Braga , Portugal
- b Centre of Health and Environmental Research, School of Allied Health Sciences , Polytechnic Institute of Porto , Porto , Portugal
| | - Sónia Silva
- c Centre of Biological Engineering , LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho , Braga , Portugal
| | - Célia F Rodrigues
- c Centre of Biological Engineering , LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho , Braga , Portugal
| | - Alistair J P Brown
- d MRC Centre for Medical Mycology , Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen , Aberdeen , UK
| | - Mariana Henriques
- c Centre of Biological Engineering , LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho , Braga , Portugal
| | - Margarida Casal
- a Centre of Molecular and Environmental Biology, Department of Biology , University of Minho , Braga , Portugal
| | - Sandra Paiva
- a Centre of Molecular and Environmental Biology, Department of Biology , University of Minho , Braga , Portugal
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The PHR Family: The Role of Extracellular Transglycosylases in Shaping Candida albicans Cells. J Fungi (Basel) 2017; 3:jof3040059. [PMID: 29371575 PMCID: PMC5753161 DOI: 10.3390/jof3040059] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/19/2017] [Accepted: 10/24/2017] [Indexed: 01/25/2023] Open
Abstract
Candida albicans is an opportunistic microorganism that can become a pathogen causing mild superficial mycosis or more severe invasive infections that can be life-threatening for debilitated patients. In the etiology of invasive infections, key factors are the adaptability of C. albicans to the different niches of the human body and the transition from a yeast form to hypha. Hyphal morphology confers high adhesiveness to the host cells, as well as the ability to penetrate into organs. The cell wall plays a crucial role in the morphological changes C. albicans undergoes in response to specific environmental cues. Among the different categories of enzymes involved in the formation of the fungal cell wall, the GH72 family of transglycosylases plays an important assembly role. These enzymes cut and religate β-(1,3)-glucan, the major determinant of cell shape. In C. albicans, the PHR family encodes GH72 enzymes, some of which work in specific environmental conditions. In this review, we will summarize the work from the initial discovery of PHR genes to the study of the pH-dependent expression of PHR1 and PHR2, from the characterization of the gene products to the recent findings concerning the stress response generated by the lack of GH72 activity in C. albicans hyphae.
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111
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Panariello BHD, Klein MI, Pavarina AC, Duarte S. Inactivation of genes TEC1 and EFG1 in Candida albicans influences extracellular matrix composition and biofilm morphology. J Oral Microbiol 2017; 9:1385372. [PMID: 29081917 PMCID: PMC5646609 DOI: 10.1080/20002297.2017.1385372] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 09/21/2017] [Indexed: 10/29/2022] Open
Abstract
Background: Infections caused by Candida spp. have been associated with formation of a biofilm, i.e. a complex microstructure of cells adhering to a surface and embedded within an extracellular matrix (ECM). Methods: The ECMs of a wild-type (WT, SN425) and two Candida albicans mutant strains, Δ/Δ tec1 (CJN2330) and Δ/Δ efg1 (CJN2302), were evaluated. Colony-forming units (cfu), total biomass (mg), water-soluble polysaccharides (WSPs), alkali-soluble polysaccharides (ASPs), proteins (insoluble part of biofilms and matrix proteins), and extracellular DNA (eDNA) were quantified. Variable-pressure scanning electron microscopy and confocal scanning laser microscopy were performed. The biovolume (μm3/μm2) and maximum thickness (μm) of the biofilms were quantified using COMSTAT2. Results: ASP content was highest in WT (mean ± SD: 74.5 ± 22.0 µg), followed by Δ/Δ tec1 (44.0 ± 24.1 µg) and Δ/Δ efg1 (14.7 ± 5.0 µg). The protein correlated with ASPs (r = 0.666) and with matrix proteins (r = 0.670) in the WT strain. The population in Δ/Δ efg1 correlated with the protein (r = 0.734) and its biofilms exhibited the lowest biomass and biovolume, and maximum thickness. In Δ/Δ tec1, ASP correlated with eDNA (r = 0.678). Conclusion: ASP production may be linked to C. albicans cell filamentous morphology.
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Affiliation(s)
- Beatriz Helena Dias Panariello
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araraquara, Brazil
| | - Marlise I. Klein
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araraquara, Brazil
| | - Ana Claudia Pavarina
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araraquara, Brazil
| | - Simone Duarte
- Department of Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, Indianapolis, IN, USA
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Abstract
Candida albicans is among the most prevalent fungal species of the human microbiota and asymptomatically colonizes healthy individuals. However, it is also an opportunistic pathogen that can cause severe, and often fatal, bloodstream infections. The medical impact of C. albicans typically depends on its ability to form biofilms, which are closely packed communities of cells that attach to surfaces, such as tissues and implanted medical devices. In this Review, we provide an overview of the processes involved in the formation of C. albicans biofilms and discuss the core transcriptional network that regulates biofilm development. We also consider some of the advantages that biofilms provide to C. albicans in comparison with planktonic growth and explore polymicrobial biofilms that are formed by C. albicans and certain bacterial species.
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Lu M, Yu C, Cui X, Shi J, Yuan L, Sun S. Gentamicin synergises with azoles against drug-resistant Candida albicans. Int J Antimicrob Agents 2017; 51:107-114. [PMID: 28943366 DOI: 10.1016/j.ijantimicag.2017.09.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/14/2017] [Accepted: 09/14/2017] [Indexed: 11/29/2022]
Abstract
Candida spp. are the primary opportunistic pathogens of nosocomial fungal infections, causing both superficial and life-threatening systemic infections. Combination therapy for fungal infections has attracted considerable attention, especially for those caused by drug-resistant fungi. Gentamicin (GM), an aminoglycoside antibiotic, has weak antifungal activity against Fusarium spp. The aim of this study was to investigate the interactions of GM with azoles against Candida spp. and the underlying mechanisms. In a chequerboard assay, GM was found not only to work synergistically with azoles against planktonic cells of drug-resistant Candida albicans with a fractional inhibitory concentration index (FICI) of 0.13-0.14, but also synergised with fluconazole (FLC) against C. albicans biofilms pre-formed in <12 h. Synergism of GM with FLC was also confirmed in vivo in a Galleria mellonella infection model. In addition, mechanism studies showed that GM not only suppressed the efflux pump of resistant C. albicans in a dose-dependent manner but also inhibited extracellular phospholipase activity of resistant C. albicans when combined with FLC. These findings suggest that GM enhances the efficacy of azoles against resistant C. albicans via efflux inhibition and decreased activity of extracellular phospholipase.
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Affiliation(s)
- Mengjiao Lu
- School of Pharmaceutical Sciences, Shandong University, Ji'nan 250012, Shandong Province, China
| | - Cuixiang Yu
- Respiration Medicine, Qianfoshan Hospital Affiliated to Shandong University, Ji'nan, Shandong Province, China
| | - Xueyan Cui
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Ji'nan, 250014, Shandong Province, China
| | - Jinyi Shi
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Ji'nan, 250014, Shandong Province, China
| | - Lei Yuan
- Department of Pharmacy, Baodi People's Hospital, Baodi 301800, Tianjin, China
| | - Shujuan Sun
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Ji'nan, 250014, Shandong Province, China.
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114
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Abstract
We focus this article on turning a biofilm inside out. The "inside" of the biofilm comprises the individual biofilm-related phenotypes, their environmental drivers and genetic determinants, and the coordination of gene functions through transcriptional regulators. Investigators have viewed the inside of the biofilm through diverse approaches, and this article will attempt to capture the essence of many. The ultimate goal is to connect the inside to the "outside," which we view as biofilm structure, development, pharmacological attributes, and medical impact.
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VILA T, FONSECA B, DA CUNHA M, DOS SANTOS G, ISHIDA K, BARRETO-BERGTER E, DE SOUZA W, ROZENTAL S. Candida albicansbiofilms: comparative analysis of room-temperature and cryofixation for scanning electron microscopy. J Microsc 2017; 267:409-419. [DOI: 10.1111/jmi.12580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 04/25/2017] [Accepted: 04/26/2017] [Indexed: 12/16/2022]
Affiliation(s)
- T. VILA
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - B.B. FONSECA
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - M.M.L. DA CUNHA
- Núcleo Multidisciplinar de Pesquisa em Biologia UFRJ-Xerém-NUMPEX-BIO; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - G.R.C. DOS SANTOS
- Instituto de Bioquímica Médica; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - K. ISHIDA
- Instituto de Ciências Biomédicas; Universidade de São Paulo; São Paulo Brasil
| | - E. BARRETO-BERGTER
- Instituto de Microbiologia Prof. Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - W. DE SOUZA
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - S. ROZENTAL
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
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Rodrigues CF, Silva S, Azeredo J, Henriques M. Candida glabrata's recurrent infections: biofilm formation during Amphotericin B treatment. Lett Appl Microbiol 2017; 63:77-81. [PMID: 27259377 DOI: 10.1111/lam.12600] [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: 03/02/2016] [Revised: 05/30/2016] [Accepted: 05/31/2016] [Indexed: 12/18/2022]
Abstract
UNLABELLED Candida species are responsible for recurrent human infections, mostly in immunocompromised patients, due to their high vulnerability. Candida glabrata has a major role in systemic candidiasis and Amphotericin B (AmB), a polyene only used in hospitals, is frequently used to treat this disease. Lately, however, clinical evidences of Candida recurrent infections during these treatments are being described, probably due to biofilm (re)formation during this therapy. Thus, this work aims at inferring if C. glabrata biofilms are still being formed during AmB treatment. For that, C. glabrata biofilms were formed in the presence of AmB and analysed by dry weight. Matrix composition was analysed quantifying carbohydrates and, specifically, β-1,3 glucans. Results demonstrated that, although in a lesser extent, C. glabrata is able to develop biofilms in the presence of AmB, with a thick extracellular matrix, with an increase on carbohydrates, especially β-1,3 glucans. Therefore, it is confirmed that complex biofilms of C. glabrata can be formed during an AmB treatment. SIGNIFICANCE AND IMPACT OF THE STUDY This study shows new insights regarding recurrent candidiasis. The authors demonstrated that Amphotericin B did not totally prevent the development of biofilms during Candida glabrata's infection treatment and that the change in the biofilm matrices may have a high responsibility for the fail in the treatment of systemic candidiasis.
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Affiliation(s)
- C F Rodrigues
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
| | - S Silva
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
| | - J Azeredo
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
| | - M Henriques
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
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Rodrigues CF, Gonçalves B, Rodrigues ME, Silva S, Azeredo J, Henriques M. The Effectiveness of Voriconazole in Therapy of Candida glabrata's Biofilms Oral Infections and Its Influence on the Matrix Composition and Gene Expression. Mycopathologia 2017; 182:653-664. [PMID: 28439794 DOI: 10.1007/s11046-017-0135-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/16/2017] [Indexed: 11/25/2022]
Abstract
Candida glabrata is one of most prevalent yeast in fungal infections, especially in immunocompromised patients. Its azole resistance results in a low therapeutic response, particularly when associated with biofilms. The main goal of this work was to study the effectiveness of voriconazole (Vcz) against C. glabrata biofilms oral pathologies, as esophageal or oropharyngeal candidiasis. Antifungal susceptibilities were determined in pre-formed 24-h-biofilms and ERG genes expression was determined by qRT-PCR. Protein quantification was performed using BCA® Kit, carbohydrate was estimated according to the Dubois assay and β-1,3 glucans concentration were determined using Glucatell® kit. Finally, ergosterol, Vcz, and fluconazole (Flu) concentrations within the biofilm matrices were determined by RP-HPLC. Results showed that C. glabrata biofilms were more susceptible to Vcz than to Flu and that ERG genes expression evidenced an overexpression of the three ERG genes in the presence of both azoles. The matrix content presented a remarked decrease in proteins and an increase in carbohydrates, namely β-1,3 glucans. Ergosterol was successfully detected and quantified in the biofilm matrices, with no differences in all the considered conditions. Vcz demonstrated better diffusion through the biofilms and better cell penetration capacities, than Flu, indicating that the structure of the drug molecule fully influences its dissemination through the biofilm matrices. This work showed that Vcz is notably more effective than Flu for the treatment of resistant C. glabrata oral biofilms, which demonstrates a clinical relevance in its future use for the treatment of oropharyngeal/esophageal candidiasis caused by this species.
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Affiliation(s)
- Célia F Rodrigues
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057, Braga, Portugal.
| | - Bruna Gonçalves
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057, Braga, Portugal
| | - Maria Elisa Rodrigues
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057, Braga, Portugal
| | - Sónia Silva
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057, Braga, Portugal
| | - Joana Azeredo
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057, Braga, Portugal
| | - Mariana Henriques
- CEB, Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057, Braga, Portugal
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Abstract
We focus this article on turning a biofilm inside out. The "inside" of the biofilm comprises the individual biofilm-related phenotypes, their environmental drivers and genetic determinants, and the coordination of gene functions through transcriptional regulators. Investigators have viewed the inside of the biofilm through diverse approaches, and this article will attempt to capture the essence of many. The ultimate goal is to connect the inside to the "outside," which we view as biofilm structure, development, pharmacological attributes, and medical impact.
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Affiliation(s)
- Katherine Lagree
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Aaron P Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
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119
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Abstract
A majority of infections caused by Candida albicans—the most frequent fungal pathogen—are associated with biofilm formation. A salient feature of C. albicans biofilms is the presence of the biofilm matrix. This matrix is composed of exopolymeric materials secreted by sessile cells within the biofilm, in which all classes of macromolecules are represented, and provides protection against environmental challenges. In this review, we summarize the knowledge accumulated during the last two decades on the composition, structure, and function of the C. albicans biofilm matrix. Knowledge of the matrix components, its structure, and function will help pave the way to novel strategies to combat C. albicans biofilm infections.
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120
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Rodrigues CF, Rodrigues ME, Silva S, Henriques M. Candida glabrata Biofilms: How Far Have We Come? J Fungi (Basel) 2017; 3:E11. [PMID: 29371530 PMCID: PMC5715960 DOI: 10.3390/jof3010011] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/07/2017] [Accepted: 02/16/2017] [Indexed: 11/25/2022] Open
Abstract
Infections caused by Candida species have been increasing in the last decades and can result in local or systemic infections, with high morbidity and mortality. After Candida albicans, Candida glabrata is one of the most prevalent pathogenic fungi in humans. In addition to the high antifungal drugs resistance and inability to form hyphae or secret hydrolases, C. glabrata retain many virulence factors that contribute to its extreme aggressiveness and result in a low therapeutic response and serious recurrent candidiasis, particularly biofilm formation ability. For their extraordinary organization, especially regarding the complex structure of the matrix, biofilms are very resistant to antifungal treatments. Thus, new approaches to the treatment of C. glabrata's biofilms are emerging. In this article, the knowledge available on C. glabrata's resistance will be highlighted, with a special focus on biofilms, as well as new therapeutic alternatives to control them.
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Affiliation(s)
- Célia F Rodrigues
- CEB, Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal.
| | - Maria Elisa Rodrigues
- CEB, Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal.
| | - Sónia Silva
- CEB, Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal.
| | - Mariana Henriques
- CEB, Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal.
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121
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O'Donnell LE, Alalwan HKA, Kean R, Calvert G, Nile CJ, Lappin DF, Robertson D, Williams C, Ramage G, Sherry L. Candida albicans biofilm heterogeneity does not influence denture stomatitis but strongly influences denture cleansing capacity. J Med Microbiol 2017; 66:54-60. [PMID: 28032543 DOI: 10.1099/jmm.0.000419] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Approximately 20 % of the UK population wear some form of denture prosthesis, resulting in denture stomatitis in half of these individuals. Candida albicans is primarily attributed as the causative agent, due to its biofilm -forming ability. Recently, there has been increasing evidence of C. albicans biofilm heterogeneity and the negative impact it can have clinically; however, this phenomenon has yet to be studied in relation to denture isolates. The aims of this study were to evaluate C. albicans biofilm formation of clinical denture isolates in a denture environment and to assess antimicrobial activity of common denture cleansers against these tenacious communities. C. albicans isolated from dentures of healthy and diseased individuals was quantified using real-time PCR and biofilm biomass assessed using crystal violet. Biofilm development on the denture substratum poly(methyl methacrylate), Molloplast B and Ufi-gel was determined. Biofilm formation was assessed using metabolic and biomass stains, following treatment with denture hygiene products. Although C. albicans was detected in greater quantities in diseased individuals, it was not associated with increased biofilm biomass. Denture substrata were shown to influence biofilm biomass, with poly(methyl methacrylate) providing the most suitable environment for C. albicans to reside. Of all denture hygiene products tested, Milton had the most effective antimicrobial activity, reducing biofilm biomass and viability the greatest. Overall, our results highlight the complex nature of denture- related disease, and disease development cannot always be attributed to a sole cause. It is the distinct combination of various factors that ultimately determines the pathogenic outcome.
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Affiliation(s)
- Lindsay E O'Donnell
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Hasanain K A Alalwan
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Ryan Kean
- Institute of Healthcare Policy and Practice, School of Health, Nursing and Midwifery, University of the West of Scotland, UK
| | - Gareth Calvert
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Christopher J Nile
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - David F Lappin
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Douglas Robertson
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Craig Williams
- Institute of Healthcare Policy and Practice, School of Health, Nursing and Midwifery, University of the West of Scotland, UK
| | - Gordon Ramage
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Leighann Sherry
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK.,Institute of Healthcare Policy and Practice, School of Health, Nursing and Midwifery, University of the West of Scotland, UK
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122
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Scorzoni L, de Paula E Silva ACA, Marcos CM, Assato PA, de Melo WCMA, de Oliveira HC, Costa-Orlandi CB, Mendes-Giannini MJS, Fusco-Almeida AM. Antifungal Therapy: New Advances in the Understanding and Treatment of Mycosis. Front Microbiol 2017; 8:36. [PMID: 28167935 PMCID: PMC5253656 DOI: 10.3389/fmicb.2017.00036] [Citation(s) in RCA: 243] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/06/2017] [Indexed: 01/08/2023] Open
Abstract
The high rates of morbidity and mortality caused by fungal infections are associated with the current limited antifungal arsenal and the high toxicity of the compounds. Additionally, identifying novel drug targets is challenging because there are many similarities between fungal and human cells. The most common antifungal targets include fungal RNA synthesis and cell wall and membrane components, though new antifungal targets are being investigated. Nonetheless, fungi have developed resistance mechanisms, such as overexpression of efflux pump proteins and biofilm formation, emphasizing the importance of understanding these mechanisms. To address these problems, different approaches to preventing and treating fungal diseases are described in this review, with a focus on the resistance mechanisms of fungi, with the goal of developing efficient strategies to overcoming and preventing resistance as well as new advances in antifungal therapy. Due to the limited antifungal arsenal, researchers have sought to improve treatment via different approaches, and the synergistic effect obtained by the combination of antifungals contributes to reducing toxicity and could be an alternative for treatment. Another important issue is the development of new formulations for antifungal agents, and interest in nanoparticles as new types of carriers of antifungal drugs has increased. In addition, modifications to the chemical structures of traditional antifungals have improved their activity and pharmacokinetic parameters. Moreover, a different approach to preventing and treating fungal diseases is immunotherapy, which involves different mechanisms, such as vaccines, activation of the immune response and inducing the production of host antimicrobial molecules. Finally, the use of a mini-host has been encouraging for in vivo testing because these animal models demonstrate a good correlation with the mammalian model; they also increase the speediness of as well as facilitate the preliminary testing of new antifungal agents. In general, many years are required from discovery of a new antifungal to clinical use. However, the development of new antifungal strategies will reduce the therapeutic time and/or increase the quality of life of patients.
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Affiliation(s)
- Liliana Scorzoni
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Ana C A de Paula E Silva
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Caroline M Marcos
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Patrícia A Assato
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Wanessa C M A de Melo
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Haroldo C de Oliveira
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Caroline B Costa-Orlandi
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Maria J S Mendes-Giannini
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
| | - Ana M Fusco-Almeida
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas Araraquara, Brasil
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Bandara HMHN, Matsubara VH, Samaranayake LP. Future therapies targeted towards eliminating Candida biofilms and associated infections. Expert Rev Anti Infect Ther 2016; 15:299-318. [PMID: 27927053 DOI: 10.1080/14787210.2017.1268530] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Candida species are common human commensals and cause either superficial or invasive opportunistic infections. The biofilm form of candida as opposed to its suspended, planktonic form, is predominantly associated with these infections. Alternative or adjunctive therapies are urgently needed to manage Candida infections as the currently available short arsenal of antifungal drugs has been compromised due to their systemic toxicity, cross-reactivity with other drugs, and above all, by the emergence of drug-resistant Candida species due to irrational drug use. Areas covered: Combination anti-Candida therapies, antifungal lock therapy, denture cleansers, and mouth rinses have all been proposed as alternatives for disrupting candidal biofilms on different substrates. Other suggested approaches for the management of candidiasis include the use of natural compounds, such as probiotics, plants extracts and oils, antifungal quorum sensing molecules, anti-Candida antibodies and vaccines, cytokine therapy, transfer of primed immune cells, photodynamic therapy, and nanoparticles. Expert commentary: The sparsity of currently available antifungals and the plethora of proposed anti-candidal therapies is a distinct indication of the urgent necessity to develop efficacious therapies for candidal infections. Alternative drug delivery approaches, such as probiotics, reviewed here is likely to be a reality in clinical settings in the not too distant future.
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Affiliation(s)
- H M H N Bandara
- a School of Dentistry , The University of Queensland , Herston , QLD , Australia
| | - V H Matsubara
- b School of Dentistry , University of São Paulo , São Paulo , SP , Brazil.,c Department of Microbiology, Institute of Biomedical Sciences , University of São Paulo , São Paulo , SP , Brazil
| | - L P Samaranayake
- a School of Dentistry , The University of Queensland , Herston , QLD , Australia.,d Faculty of Dentistry , University of Kuwait , Kuwait
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124
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Abstract
Candida albicans is the most common human fungal pathogen causing diseases ranging from mucosal to systemic infections. As a commensal, C. albicans asymptomatically colonizes mucosal surfaces; however, any disruption in the host environment or under conditions of immune dysfunction, C. albicans can proliferate and invade virtually any site in the host. The ability of this highly adaptable fungal species to transition from commensal to pathogen is due to a repertoire of virulence factors. Specifically, the ability to switch morphology and form biofilms are properties central to C. albicans pathogenesis. In fact, the majority of C. albicans infections are associated with biofilm formation on host or abiotic surfaces such as indwelling medical devices, which carry high morbidity and mortality. Significantly, biofilms formed by C. albicans are inherently tolerant to antimicrobial therapy and therefore, the susceptibility of Candida biofilms to the current therapeutic agents remains low. The aim of this review is to provide an overview of C. albicans highlighting some of the diverse biofilm-associated diseases caused by this opportunistic pathogen and the animal models available to study them. Further, the classes of antifungal agents used to combat these resilient infections are discussed along with mechanisms of drug resistance.
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125
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Woolford CA, Lagree K, Xu W, Aleynikov T, Adhikari H, Sanchez H, Cullen PJ, Lanni F, Andes DR, Mitchell AP. Bypass of Candida albicans Filamentation/Biofilm Regulators through Diminished Expression of Protein Kinase Cak1. PLoS Genet 2016; 12:e1006487. [PMID: 27935965 PMCID: PMC5147786 DOI: 10.1371/journal.pgen.1006487] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/15/2016] [Indexed: 12/17/2022] Open
Abstract
Biofilm formation on implanted medical devices is a major source of lethal invasive infection by Candida albicans. Filamentous growth of this fungus is tied to biofilm formation because many filamentation-associated genes are required for surface adherence. Cell cycle or cell growth defects can induce filamentation, but we have limited information about the coupling between filamentation and filamentation-associated gene expression after cell cycle/cell growth inhibition. Here we identified the CDK activating protein kinase Cak1 as a determinant of filamentation and filamentation-associated gene expression through a screen of mutations that diminish expression of protein kinase-related genes implicated in cell cycle/cell growth control. A cak1diminished expression (DX) strain displays filamentous growth and expresses filamentation-associated genes in the absence of typical inducing signals. In a wild-type background, expression of filamentation-associated genes depends upon the transcription factors Bcr1, Brg1, Efg1, Tec1, and Ume6. In the cak1 DX background, the dependence of filamentation-associated gene expression on each transcription factor is substantially relieved. The unexpected bypass of filamentation-associated gene expression activators has the functional consequence of enabling biofilm formation in the absence of Bcr1, Brg1, Tec1, Ume6, or in the absence of both Brg1 and Ume6. It also enables filamentous cell morphogenesis, though not biofilm formation, in the absence of Efg1. Because these transcription factors are known to have shared target genes, we suggest that cell cycle/cell growth limitation leads to activation of several transcription factors, thus relieving dependence on any one. The ability of the pathogen Candida albicans to grow on surfaces as biofilms is a determinant of infection ability, because biofilms on implanted medical devices seed infections. Biofilm formation by this organism requires growth in the form of filamentous cells and the expression of filamentation-associated genes. Inhibition of cell proliferation can induce filamentous cell formation, as we find here for strains that express greatly reduced levels of the cell cycle regulator Cak1. Surprisingly, biofilm formation occurs independently of many central biofilm regulatory genes when Cak1 levels are reduced. This response to proliferation inhibition may reflect the activation of numerous biofilm regulators, thus relieving the dependence on any one regulator. The stimulation of biofilm formation by proliferation inhibition, a property of many bacterial pathogens as well, may contribute to the limited effectiveness of antimicrobials against biofilms.
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Affiliation(s)
- Carol A. Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Katherine Lagree
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Wenjie Xu
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Tatyana Aleynikov
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Hema Adhikari
- Department of Biological Sciences at the University at Buffalo, Buffalo, New York, United States of America
| | - Hiram Sanchez
- Departments of Medicine and Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Paul J. Cullen
- Department of Biological Sciences at the University at Buffalo, Buffalo, New York, United States of America
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - David R. Andes
- Departments of Medicine and Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Aaron P. Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Morici P, Fais R, Rizzato C, Tavanti A, Lupetti A. Inhibition of Candida albicans Biofilm Formation by the Synthetic Lactoferricin Derived Peptide hLF1-11. PLoS One 2016; 11:e0167470. [PMID: 27902776 PMCID: PMC5130267 DOI: 10.1371/journal.pone.0167470] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/15/2016] [Indexed: 12/20/2022] Open
Abstract
The aim of this study was to evaluate the in vitro activity of the synthetic peptide hLF1-11 against biofilm produced by clinical isolates of Candida albicans with different fluconazole susceptibility. The antibiofilm activity of the peptide hLF1-11 was assessed in terms of reduction of biofilm cellular density, metabolic activity and sessile cell viability. The extent of morphogenesis in hLF1-11 treated and untreated biofilms was also investigated microscopically. Transcription levels of genes related to cell adhesion, hyphal development and extracellular matrix production were analysed by qRT-PCR in hLF1-11 treated and untreated biofilms. Exogenous dibutyryl-cAMP (db-cAMP) was used to rescue morphogenesis in cells exposed to the peptide. The results revealed that hLF1-11 exhibited an inhibitory effect on biofilm formation by all C. albicans isolates tested in a dose-dependent manner, regardless of their fluconazole susceptibility. Visual inspection of treated or untreated biofilm cells with an inverted microscope revealed a significant reduction in hyphal formation by hLF1-11 treated cells, as early as 3 hours of incubation. Moreover, hLF1-11 showed a reduced activity on preadherent cells. hLF1-11 induced the down-regulation of biofilm and hyphal-associated genes, which were predominantly regulated via the Ras1-cAMP-Efg1 pathway. Indeed, exogenous db-cAMP restored morphogenesis in hLF1-11 treated cells. The hLF1-11 peptide significantly inhibited biofilm formation by C. albicans mainly at early stages, interfering with biofilm cellular density and metabolic activity, and affected morphogenesis through the Ras1-cAMP-Efg1 pathway. Our findings provide the first evidence that hLF1-11 could represent a potential candidate for the prevention of biofilm formation by C. albicans.
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Affiliation(s)
- Paola Morici
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Roberta Fais
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Cosmeri Rizzato
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - Antonella Lupetti
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- * E-mail:
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127
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Hirota K, Yumoto H, Sapaar B, Matsuo T, Ichikawa T, Miyake Y. Pathogenic factors in Candida biofilm-related infectious diseases. J Appl Microbiol 2016; 122:321-330. [PMID: 27770500 DOI: 10.1111/jam.13330] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/11/2016] [Accepted: 10/15/2016] [Indexed: 01/07/2023]
Abstract
Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.
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Affiliation(s)
- K Hirota
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - H Yumoto
- Department of Conservative Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - B Sapaar
- Department of Oral and Maxillofacial Prosthodontics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - T Matsuo
- Department of Conservative Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - T Ichikawa
- Department of Oral and Maxillofacial Prosthodontics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Y Miyake
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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128
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Abstract
The extracellular matrix of biofilm is unique to the biofilm lifestyle, and it has key roles in community survival. A complete understanding of the biochemical nature of the matrix is integral to the understanding of the roles of matrix components. This knowledge is a first step toward the development of novel therapeutics and diagnostics to address persistent biofilm infections. Many of the assay methods needed for refined matrix composition analysis require milligram amounts of material that is separated from the cellular components of these complex communities. The protocol described here explains the large-scale production and isolation of the Candida biofilm extracellular matrix. To our knowledge, the proposed procedure is the only currently available approach in the field that yields milligram amounts of biofilm matrix. This procedure first requires biofilms to be seeded in large-surface-area roller bottles, followed by cell adhesion and biofilm maturation during continuous movement of the medium across the surface of the rotating bottle. The formed matrix is then separated from the entire biomass using sonication, which efficiently removes the matrix without perturbing the fungal cell wall. Subsequent filtration, dialysis and lyophilization steps result in a purified matrix product sufficient for biochemical, structural and functional assays. The overall protocol takes ∼11 d to complete. This protocol has been used for Candida species, but, using the troubleshooting guide provided, it could be adapted for other fungi or bacteria.
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129
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Poyntner C, Blasi B, Arcalis E, Mirastschijski U, Sterflinger K, Tafer H. The Transcriptome of Exophiala dermatitidis during Ex-vivo Skin Model Infection. Front Cell Infect Microbiol 2016; 6:136. [PMID: 27822460 PMCID: PMC5075926 DOI: 10.3389/fcimb.2016.00136] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 10/06/2016] [Indexed: 12/12/2022] Open
Abstract
The black yeast Exophiala dermatitidis is a widespread polyextremophile and human pathogen, that is found in extreme natural habitats and man-made environments such as dishwashers. It can cause various diseases ranging from phaeohyphomycosis and systemic infections, with fatality rates reaching 40%. While the number of cases in immunocompromised patients are increasing, knowledge of the infections, virulence factors and host response is still scarce. In this study, for the first time, an artificial infection of an ex-vivo skin model with Exophiala dermatitidis was monitored microscopically and transcriptomically. Results show that Exophiala dermatitidis is able to actively grow and penetrate the skin. The analysis of the genomic and RNA-sequencing data delivers a rich and complex transcriptome where circular RNAs, fusion transcripts, long non-coding RNAs and antisense transcripts are found. Changes in transcription strongly affect pathways related to nutrients acquisition, energy metabolism, cell wall, morphological switch, and known virulence factors. The L-Tyrosine melanin pathway is specifically upregulated during infection. Moreover the production of secondary metabolites, especially alkaloids, is increased. Our study is the first that gives an insight into the complexity of the transcriptome of Exophiala dermatitidis during artificial skin infections and reveals new virulence factors.
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Affiliation(s)
- Caroline Poyntner
- Department of Biotechnology, VIBT EQ Extremophile Center, University of Natural Resources and Life Sciences Vienna, Austria
| | - Barbara Blasi
- Department of Biotechnology, VIBT EQ Extremophile Center, University of Natural Resources and Life Sciences Vienna, Austria
| | - Elsa Arcalis
- Department for Applied Genetics and Cell Biology, Molecular Plant Physiology and Crop Biotechnology, University of Natural Resources and Life Sciences Vienna, Austria
| | - Ursula Mirastschijski
- Klinikum Bremen-Mitte, Department of Plastic, Reconstructive and Aesthetic Surgery, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University Bremen Bremen, Germany
| | - Katja Sterflinger
- Department of Biotechnology, VIBT EQ Extremophile Center, University of Natural Resources and Life Sciences Vienna, Austria
| | - Hakim Tafer
- Department of Biotechnology, VIBT EQ Extremophile Center, University of Natural Resources and Life Sciences Vienna, Austria
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130
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Rajendran R, May A, Sherry L, Kean R, Williams C, Jones BL, Burgess KV, Heringa J, Abeln S, Brandt BW, Munro CA, Ramage G. Integrating Candida albicans metabolism with biofilm heterogeneity by transcriptome mapping. Sci Rep 2016; 6:35436. [PMID: 27765942 PMCID: PMC5073228 DOI: 10.1038/srep35436] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/29/2016] [Indexed: 12/20/2022] Open
Abstract
Candida albicans biofilm formation is an important virulence factor in the pathogenesis of disease, a characteristic which has been shown to be heterogeneous in clinical isolates. Using an unbiased computational approach we investigated the central metabolic pathways driving biofilm heterogeneity. Transcripts from high (HBF) and low (LBF) biofilm forming isolates were analysed by RNA sequencing, with 6312 genes identified to be expressed in these two phenotypes. With a dedicated computational approach we identified and validated a significantly differentially expressed subnetwork of genes associated with these biofilm phenotypes. Our analysis revealed amino acid metabolism, such as arginine, proline, aspartate and glutamate metabolism, were predominantly upregulated in the HBF phenotype. On the contrary, purine, starch and sucrose metabolism was generally upregulated in the LBF phenotype. The aspartate aminotransferase gene AAT1 was found to be a common member of these amino acid pathways and significantly upregulated in the HBF phenotype. Pharmacological inhibition of AAT1 enzyme activity significantly reduced biofilm formation in a dose-dependent manner. Collectively, these findings provide evidence that biofilm phenotype is associated with differential regulation of metabolic pathways. Understanding and targeting such pathways, such as amino acid metabolism, is potentially useful for developing diagnostics and new antifungals to treat biofilm-based infections.
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Affiliation(s)
- Ranjith Rajendran
- School of Medicine, College of Medical, Veterinary and Life Sciences (MVLS), University of Glasgow, UK
| | - Ali May
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, The Netherlands.,Centre for Integrative Bioinformatics VU (IBIVU), VU University Amsterdam, The Netherlands
| | - Leighann Sherry
- School of Medicine, College of Medical, Veterinary and Life Sciences (MVLS), University of Glasgow, UK
| | - Ryan Kean
- School of Medicine, College of Medical, Veterinary and Life Sciences (MVLS), University of Glasgow, UK.,Institute of Healthcare Associated Infection, School of Health, Nursing and Midwifery, University of the West of Scotland, UK
| | - Craig Williams
- Institute of Healthcare Associated Infection, School of Health, Nursing and Midwifery, University of the West of Scotland, UK
| | - Brian L Jones
- Microbiology Department, Glasgow Royal Infirmary, Glasgow, UK
| | | | - Jaap Heringa
- Centre for Integrative Bioinformatics VU (IBIVU), VU University Amsterdam, The Netherlands
| | - Sanne Abeln
- Centre for Integrative Bioinformatics VU (IBIVU), VU University Amsterdam, The Netherlands
| | - Bernd W Brandt
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, The Netherlands
| | - Carol A Munro
- Aberdeen Fungal Group, MRC Centre for Medical Mycology, University of Aberdeen, UK
| | - Gordon Ramage
- School of Medicine, College of Medical, Veterinary and Life Sciences (MVLS), University of Glasgow, UK
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131
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Commensal Protection of Staphylococcus aureus against Antimicrobials by Candida albicans Biofilm Matrix. mBio 2016; 7:mBio.01365-16. [PMID: 27729510 PMCID: PMC5061872 DOI: 10.1128/mbio.01365-16] [Citation(s) in RCA: 183] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Biofilm-associated polymicrobial infections, particularly those involving fungi and bacteria, are responsible for significant morbidity and mortality and tend to be challenging to treat. Candida albicans and Staphylococcus aureus specifically are considered leading opportunistic fungal and bacterial pathogens, respectively, mainly due to their ability to form biofilms on catheters and indwelling medical devices. However, the impact of mixed-species biofilm growth on therapy remains largely understudied. In this study, we investigated the influence of C. albicans secreted cell wall polysaccharides on the response of S. aureus to antibacterial agents in biofilm. Results demonstrated significantly enhanced tolerance for S. aureus to drugs in the presence of C. albicans or its secreted cell wall polysaccharide material. Fluorescence confocal time-lapse microscopy revealed impairment of drug diffusion through the mixed biofilm matrix. Using C. albicans mutant strains with modulated cell wall polysaccharide expression, exogenous supplementation, and enzymatic degradation, the C. albicans-secreted β-1,3-glucan cell wall component was identified as the key matrix constituent providing the bacteria with enhanced drug tolerance. Further, antibody labeling demonstrated rapid coating of the bacteria by the C. albicans matrix material. Importantly, via its effect on the fungal biofilm matrix, the antifungal caspofungin sensitized the bacteria to the drugs. Understanding such symbiotic interactions with clinical relevance between microbial species in biofilms will greatly aid in overcoming the limitations of current therapies and in defining potential new targets for treating polymicrobial infections. The fungus Candida albicans and the bacterium Staphylococcus aureus are important microbial pathogens responsible for the majority of infections in hospitalized patients and are often coisolated from a host. In this study, we demonstrated that when grown together, the fungus provides the bacterium with enhanced tolerance to antimicrobial drugs. This process was mediated by polysaccharides secreted by the fungal cell into the environment. The biofilm matrix formed by these polysaccharides prevented penetration by the drugs and provided the bacteria with protection. Importantly, we show that by inhibiting the production of the fungal polysaccharides, a specific antifungal agent indirectly sensitized the bacteria to antimicrobials. Understanding the therapeutic implications of the interactions between these two diverse microbial species will aid in overcoming the limitations of current therapies and in defining new targets for treating complex polymicrobial infections.
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132
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Araújo D, Henriques M, Silva S. Portrait of Candida Species Biofilm Regulatory Network Genes. Trends Microbiol 2016; 25:62-75. [PMID: 27717660 DOI: 10.1016/j.tim.2016.09.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/01/2016] [Accepted: 09/15/2016] [Indexed: 11/15/2022]
Abstract
Most cases of candidiasis have been attributed to Candida albicans, but Candida glabrata, Candida parapsilosis and Candida tropicalis, designated as non-C. albicans Candida (NCAC), have been identified as frequent human pathogens. Moreover, Candida biofilms are an escalating clinical problem associated with significant rates of mortality. Biofilms have distinct developmental phases, including adhesion/colonisation, maturation and dispersal, controlled by complex regulatory networks. This review discusses recent advances regarding Candida species biofilm regulatory network genes, which are key components for candidiasis.
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Affiliation(s)
- Daniela Araújo
- Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal
| | - Mariana Henriques
- Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal
| | - Sónia Silva
- Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal.
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133
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Sandai D, Tabana YM, Ouweini AE, Ayodeji IO. Resistance of Candida albicans Biofilms to Drugs and the Host Immune System. Jundishapur J Microbiol 2016; 9:e37385. [PMID: 28138373 PMCID: PMC5240163 DOI: 10.5812/jjm.37385] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 09/14/2016] [Accepted: 09/14/2016] [Indexed: 01/27/2023] Open
Abstract
Background Candida albicans is a commensal fungus that resides on mucosal surfaces and in the gastrointestinal and genitourinary tracts in humans. However, it can cause an infection when the immune system of the host is impaired or if a niche becomes available. Many C. albicans infections are due to the organism’s ability to form a biofilm on implanted medical devices. A biofilm represents an optimal medium for the growth of C. albicans as it allows cells to be enclosed by a self-produced extracellular matrix (ECM). Objectives The present work investigated certain aspects of the resistance of C. albicans biofilms to drugs and the host immune system. Results An ECM was found to provide the infrastructure for biofilm formation, prevent disaggregation, and shield encapsulated C. albicans cells from antifungal drugs and the host’s immune system. By influencing FKS1 and upregulating multiple glucan modification genes, β-1, 3-glucan, an important component of ECM, was shown to be responsible for many of the biofilm’s drug-resistant properties. On being engulfed by ECM, the fungal cell was found to switch from glycolysis to gluconeogenesis. Resembling the cellular response to starvation, this was followed by the activation of the glyoxylate cycle that allowed the use of simple molecules as energy sources. Conclusion Mature biofilms were found to be much more resistant to antifungal agents and the host immune system than free cells. The factors responsible for high resistance included the complex architecture of biofilms, ECM, increased expression of drug efflux pumps, and metabolic plasticity.
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Affiliation(s)
- Doblin Sandai
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
- Corresponding author: Doblin Sandai, Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia. Tel: +60-45622386, E-mail: ,
| | - Yasser M Tabana
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
| | - Ahmad El Ouweini
- School of Pharmacy, Lebanese American University, Byblos, Lebanon
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134
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The Extracellular Matrix of Candida albicans Biofilms Impairs Formation of Neutrophil Extracellular Traps. PLoS Pathog 2016; 12:e1005884. [PMID: 27622514 PMCID: PMC5021349 DOI: 10.1371/journal.ppat.1005884] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/21/2016] [Indexed: 12/31/2022] Open
Abstract
Neutrophils release extracellular traps (NETs) in response to planktonic C. albicans. These complexes composed of DNA, histones, and proteins inhibit Candida growth and dissemination. Considering the resilience of Candida biofilms to host defenses, we examined the neutrophil response to C. albicans during biofilm growth. In contrast to planktonic C. albicans, biofilms triggered negligible release of NETs. Time lapse imaging confirmed the impairment in NET release and revealed neutrophils adhering to hyphae and migrating on the biofilm. NET inhibition depended on an intact extracellular biofilm matrix as physical or genetic disruption of this component resulted in NET release. Biofilm inhibition of NETosis could not be overcome by protein kinase C activation via phorbol myristate acetate (PMA) and was associated with suppression of neutrophil reactive oxygen species (ROS) production. The degree of impaired NET release correlated with resistance to neutrophil attack. The clinical relevance of the role for extracellular matrix in diminishing NET production was corroborated in vivo using a rat catheter model. The C. albicans pmr1Δ/Δ, defective in production of matrix mannan, appeared to elicit a greater abundance of NETs by scanning electron microscopy imaging, which correlated with a decreased fungal burden. Together, these findings show that C. albicans biofilms impair neutrophil response through an inhibitory pathway induced by the extracellular matrix.
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135
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Martínez JP, Blanes R, Casanova M, Valentín E, Murgui A, Domínguez Á. Null mutants of Candida albicans for cell-wall-related genes form fragile biofilms that display an almost identical extracellular matrix proteome. FEMS Yeast Res 2016; 16:fow075. [PMID: 27609602 DOI: 10.1093/femsyr/fow075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2016] [Indexed: 12/20/2022] Open
Abstract
By two-dimensional gel electrophoresis (2-DE) and mass spectrometry, we have characterized the polypeptide species present in extracts obtained by 60% ethanol treatment of whole mature (48 h) biofilms formed by a reference strain (CAI4-URA3) and four Candida albicans null mutants for cell-wall-related genes (ALG5, CSA1, MNN9 and PGA10) Null mutants form fragile biofilms that appeared partially split and weakly attached to the substratum contrary to those produced by the reference strain. An almost identical, electrophoretic profile consisting of about 276 spots was visualized in all extracts examined. Proteomic analysis led to the identification of 131 polypeptides, corresponding to 86 different protein species, being the rest isoforms-83 displayed negative hydropathic indexes and 82 lack signal peptide. The majority of proteins appeared at pI between 4 and 6, and molecular mass between 10 and 94 kDa. The proteins identified belonged to the following Gene Ontology categories: 21.9% unknown molecular function, 16.2% oxidoreductase activity, 13.3% hydrolase activity and 41.8% distributed between other different GO categories. Strong defects in biofilm formation appreciated in the cell-wall mutant strains could be attributed to defects in aggregation due to abnormal cell wall formation rather than to differences in the biofilm extracellular matrix composition.
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Affiliation(s)
- José P Martínez
- Department of Microbiology and Ecology, School of Pharmacy, University of Valencia, 46100 Burjasot, Valencia, Spain
| | - Rosario Blanes
- Department of Microbiology and Ecology, School of Pharmacy, University of Valencia, 46100 Burjasot, Valencia, Spain
| | - Manuel Casanova
- Department of Microbiology and Ecology, School of Pharmacy, University of Valencia, 46100 Burjasot, Valencia, Spain
| | - Eulogio Valentín
- Department of Microbiology and Ecology, School of Pharmacy, University of Valencia, 46100 Burjasot, Valencia, Spain
| | - Amelia Murgui
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Valencia, 46100 Burjasot, Valencia, Spain
| | - Ángel Domínguez
- Department of Microbiology and Genetics, University of Salamanca, 37007 Salamanca, Spain
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136
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Chen X, Zhang R, Takada A, Iwatani S, Oka C, Kitamoto T, Kajiwara S. The role of Bgl2p in the transition to filamentous cells during biofilm formation by Candida albicans. Mycoses 2016; 60:96-103. [PMID: 27597232 DOI: 10.1111/myc.12554] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 11/29/2022]
Abstract
The fungal pathogen Candida albicans undergoes a transition from yeast cells to filamentous cells that is related to its pathogenicity. The complex multicellular processes involved in biofilm formation by this fungus also include this transition. In this work, we investigated the morphological role of the Bgl2 protein (Bgl2p) in the transition to filamentous cells during biofilm formation by C. albicans. Bgl2p has been identified as a β-1, 3-glucosyltransferase, and transcription of the CaBGL2 gene is upregulated during biofilm formation. We used scanning electron microscopy to observe the microstructure of a bgl2 null mutant during biofilm formation and found a delay in the transition to filamentous cells in the premature phase (24 hours) of biofilm formation. Deletion of the CaBGL2 gene led to a decrease in the expression of CPH2 and TEC1, which encode transcription factors required for the transition to the filamentous form. These findings indicate that Bgl2p plays a role in the transition to filamentous cells during biofilm formation by C. albicans.
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Affiliation(s)
- Xinyue Chen
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Ruoyu Zhang
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Ayako Takada
- Biomaterials Analysis Division, Technical Department, Tokyo Institute of Technology, Yokohama, Japan
| | - Shun Iwatani
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Chiemi Oka
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Toshitaka Kitamoto
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Susumu Kajiwara
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
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137
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Abstract
Candida albicans, the most pervasive fungal pathogen that colonizes humans, forms biofilms that are architecturally complex. They consist of a basal yeast cell polylayer and an upper region of hyphae encapsulated in extracellular matrix. However, biofilms formed in vitro vary as a result of the different conditions employed in models, the methods used to assess biofilm formation, strain differences, and, in a most dramatic fashion, the configuration of the mating type locus (MTL). Therefore, integrating data from different studies can lead to problems of interpretation if such variability is not taken into account. Here we review the conditions and factors that cause biofilm variation, with the goal of engendering awareness that more attention must be paid to the strains employed, the methods used to assess biofilm development, every aspect of the model employed, and the configuration of the MTL locus. We end by posing a set of questions that may be asked in comparing the results of different studies and developing protocols for new ones. This review should engender the notion that not all biofilms are created equal.
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Affiliation(s)
- David R Soll
- Developmental Studies Hybridoma Bank, Department of Biology, The University of Iowa, Iowa City, Iowa, USA
| | - Karla J Daniels
- Developmental Studies Hybridoma Bank, Department of Biology, The University of Iowa, Iowa City, Iowa, USA
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138
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Ishola OA, Ting SY, Tabana YM, Ahmed MA, Yunus MA, Mohamed R, Lung Than LT, Sandai D. The Role of Isocitrate Lyase (ICL1) in the Metabolic Adaptation of Candida albicans Biofilms. Jundishapur J Microbiol 2016; 9:e38031. [PMID: 27800147 PMCID: PMC5086032 DOI: 10.5812/jjm.38031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 08/14/2016] [Accepted: 08/19/2016] [Indexed: 11/21/2022] Open
Abstract
Background A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility. Objectives This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components. Methods Growth, adhesion, biofilm formation, and cell wall carbohydrate composition were quantified for isogenic Candida albicans ICL1/ICL1, ICL1/icl1, and icl1/icl1 strains. The morphology and topography of these strains were compared by light microscopy and scanning electron microscopy. FKS1 (glucan synthase), ERG11 (14-α-demethylase), and CDR2 (efflux pump) mRNA levels were quantified using qRT-PCR. Results The ICL1/icl1 and icl1/icl1 strains formed similar biofilms and exhibited analogous drug-tolerance levels to the control ICL1/ICL1 strains. Furthermore, the drug sequestration ability of β-1, 3-glucan, a major carbohydrate component of the extracellular matrix, was not impaired. However, the inactivation of ICL1 did impair morphogenesis. ICL1 deletion also had a considerable effect on the expression of the FKS1, ERG11, and CDR2 genes. FKS1 and ERG11 were upregulated in ICL1/icl1 and icl1/icl1 cells throughout the biofilm developmental stages, and CDR2 was upregulated at the early phase. However, their expression was downregulated compared to the control ICL1/ICL1 strain. Conclusions We conclude that the glyoxylate cycle is not a specific determinant of biofilm drug resistance.
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Affiliation(s)
| | - Seng Yeat Ting
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
| | - Yasser M Tabana
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
| | - Mowaffaq Adam Ahmed
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
| | - Muhammad Amir Yunus
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
| | - Rafeezul Mohamed
- Regenerative Medicine Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
| | - Leslie Thian Lung Than
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Doblin Sandai
- Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia
- Corresponding author: Doblin Sandai, Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia. Tel: +60-45622386, Fax: +60-194951073, E-mail: ,
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139
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Abstract
Biofilm infections are exceptionally recalcitrant to antimicrobial treatment or clearance by host immune responses. Within biofilms, microbes form adherent multicellular communities that are embedded in an extracellular matrix. Many prescribed antifungal drugs are not effective against biofilm infections owing to several protective factors including poor diffusion of drugs through biofilms as well as specific drug-matrix interactions. Despite the key roles that biofilms play in infections, there is little quantitative information about their composition and structural complexity because of the analytical challenge of studying these dense networks using traditional techniques. Within this review, recent work to elucidate fungal biofilm composition is discussed, with particular attention given to the challenges of annotation and quantification of matrix composition.
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140
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Falsetta ML, Foster DC, Bonham AD, Phipps RP. A review of the available clinical therapies for vulvodynia management and new data implicating proinflammatory mediators in pain elicitation. BJOG 2016; 124:210-218. [PMID: 27312009 DOI: 10.1111/1471-0528.14157] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2016] [Indexed: 12/19/2022]
Abstract
Localised provoked vulvodynia (LPV) is a common, chronic, and disabling condition: patients experience profound pain and a diminished quality of life. The aetiologic origins of vulvodynia are poorly understood, yet recent evidence suggests a link to site-specific inflammatory responses. Fibroblasts isolated from the vestibule of LPV patients are sensitive to proinflammatory stimuli and copiously produce pain-associated proinflammatory mediators (IL-6 and PGE2 ). Although LPV is a multifactorial disorder, understanding vulvar inflammation and targeting the inflammatory response should lead to treatment advances, especially for patients exhibiting signs of inflammation. NFκB (already targeted clinically) or other inflammatory components may be suitable therapeutic targets. TWEETABLE ABSTRACT Vulvodynia is a poorly understood, prevalent, and serious women's health issue requiring better understanding to improve therapy.
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Affiliation(s)
- M L Falsetta
- Department of Environmental Medicine, University of Rochester, Rochester, NY, USA
| | - D C Foster
- Department of Obstetrics and Gynecology, University of Rochester, Rochester, NY, USA
| | - A D Bonham
- Department of Obstetrics and Gynecology, University of Rochester, Rochester, NY, USA
| | - R P Phipps
- Department of Environmental Medicine, University of Rochester, Rochester, NY, USA.,Department of Obstetrics and Gynecology, University of Rochester, Rochester, NY, USA.,Department of Microbiology and Immunology, University of Rochester, Rochester, NY, USA
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141
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Abstract
In humans, microbial cells (including bacteria, archaea, and fungi) greatly outnumber host cells. Candida albicans is the most prevalent fungal species of the human microbiota; this species asymptomatically colonizes many areas of the body, particularly the gastrointestinal and genitourinary tracts of healthy individuals. Alterations in host immunity, stress, resident microbiota, and other factors can lead to C. albicans overgrowth, causing a wide range of infections, from superficial mucosal to hematogenously disseminated candidiasis. To date, most studies of C. albicans have been carried out in suspension cultures; however, the medical impact of C. albicans (like that of many other microorganisms) depends on its ability to thrive as a biofilm, a closely packed community of cells. Biofilms are notorious for forming on implanted medical devices, including catheters, pacemakers, dentures, and prosthetic joints, which provide a surface and sanctuary for biofilm growth. C. albicans biofilms are intrinsically resistant to conventional antifungal therapeutics, the host immune system, and other environmental perturbations, making biofilm-based infections a significant clinical challenge. Here, we review our current knowledge of biofilms formed by C. albicans and closely related fungal species.
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Affiliation(s)
- Clarissa J Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California 95343;
| | - Alexander D Johnson
- Department of Microbiology and Immunology, University of California, San Francisco, California 94143;
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142
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Abstract
Fungal biofilms have become an increasingly important clinical problem. The widespread use of antibiotics, frequent use of indwelling medical devices, and a trend toward increased patient immunosuppression have resulted in a creation of opportunity for clinically important yeasts and molds to form biofilms. This review will discuss the diversity and importance of fungal biofilms in the context of clinical medicine, provide novel insights into the clinical management of fungal biofilm infection, present evidence why these structures are recalcitrant to antifungal therapy, and discuss how our knowledge and understanding may lead to novel therapeutic intervention.
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143
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Sheppard DC, Howell PL. Biofilm Exopolysaccharides of Pathogenic Fungi: Lessons from Bacteria. J Biol Chem 2016; 291:12529-12537. [PMID: 27129222 DOI: 10.1074/jbc.r116.720995] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Exopolysaccharides play an important structural and functional role in the development and maintenance of microbial biofilms. Although the majority of research to date has focused on the exopolysaccharide systems of biofilm-forming bacteria, recent studies have demonstrated that medically relevant fungi such as Candida albicans and Aspergillus fumigatus also form biofilms during infection. These fungal biofilms share many similarities with those of bacteria, including the presence of secreted exopolysaccharides as core components of the extracellular matrix. This review will highlight our current understanding of fungal biofilm exopolysaccharides, as well as the parallels that can be drawn with those of their bacterial counterparts.
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Affiliation(s)
- Donald C Sheppard
- Departments of Medicine, Microbiology and Immunology, Research Institute of the McGill University Health Centre, McGill University, Montréal, Québec H4A 3J1; Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, McGill University, Montréal, Québec H4A 3J1.
| | - P Lynne Howell
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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144
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Abstract
Fungal infections constitute a major threat to an escalating number of critically ill patients. Fungi are eukaryotic organisms and, as such, there is a limited armamentarium of antifungal drugs, which leads to high mortality rates. Moreover, fungal infections are often associated with the formation of biofilms, which contribute to virulence and further complicate treatment due to the high level of antifungal drug resistance displayed by sessile cells within these microbial communities. Thus, the treatment of fungal infections associated with a biofilm etiology represents a formidable and unmet clinical challenge. The increasing importance and awareness of fungal biofilms is reflected by the fact that this is now an area of very active research. Studies in the last decade have provided important insights into fungal biofilm biology, physiology, and pathology, as well as into the molecular basis of biofilm resistance. Here we discuss how this accumulated knowledge may inform the development of new antibiofilm strategies and therapeutics that are urgently needed.
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145
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Abstract
The fungus Candida albicans is a major source of device-associated infection because of its capacity for biofilm formation. It is part of the natural mucosal flora and thus has access to available niches that can lead to infection. In this chapter we discuss the major properties of C. albicans biofilms and the insight that has been gleaned from their genetic determinants. Our specific areas of focus include biofilm structure and development, cell morphology and biofilm formation, biofilm-associated gene expression, the cell surface and adherence, the extracellular matrix, biofilm metabolism, and biofilm drug resistance.
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146
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Shirazi F, Kontoyiannis DP. Micafungin triggers caspase-dependent apoptosis in Candida albicans and Candida parapsilosis biofilms, including caspofungin non-susceptible isolates. Virulence 2016; 6:385-94. [PMID: 26065323 DOI: 10.1080/21505594.2015.1027479] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Candida biofilms play an important role in infections associated with medical devices and are resistant to antifungals. We hypothesized that the echinocandin micafungin (MICA) exerts an enhanced antifungal activity against caspofungin (CAS)-susceptible (CAS-S) and CAS-non-susceptible (CAS-NS) Candida albicans and Candida parapsilosis which is at least in part through apoptosis, even in the biofilm environment. Apoptosis was characterized by detecting reactive oxygen species (ROS) accumulation, depolarization of mitochondrial membrane potential (MMP), DNA fragmentation, lack of plasma membrane integrity, and metacaspase activation following exposure of Candida biofilm to MICA for 3h at 37°C in RPMI 1640 medium. The minimum inhibitory concentration was higher for CAS (2.0-16.0 μg/mL) than for MICA (1.0-8.0 μg/mL) for Candida biofilms. Elevated intracellular ROS levels and depolarization of MMP was evident in CAS-S C. albicans (3.0-4.2 fold) and C. parapsilosis (4.8-5.4 fold) biofilms compared with CAS-NS (1.2 fold) after exposure to MICA (0.25x-1xMIC). Elevated intracellular ROS levels and depolarization of MMP was evident in CAS-S C. albicans (3.0-4.2 fold) and C. parapsilosis (4.8-5.4 fold) biofilms compared with CAS-NS (1.2 fold) after exposure to MICA (0.25x-1xMIC). Finally higher ß-1, 3 glucan levels were seen in sessile cells compared to planktonic cells, especially in CAS-NS strains. MICA treatment might induce a metacaspase-dependent apoptotic process in biofilms of both CAS-S C. albicans and C. parapsilosis, and to some degree in CAS-NS strains.
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Affiliation(s)
- F Shirazi
- a Department of Infectious Diseases; Infection Control and Employee Health ; The University of Texas MD Anderson Cancer Center ; Houston , TX USA
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147
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Höfs S, Mogavero S, Hube B. Interaction of Candida albicans with host cells: virulence factors, host defense, escape strategies, and the microbiota. J Microbiol 2016; 54:149-69. [DOI: 10.1007/s12275-016-5514-0] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/03/2015] [Accepted: 11/07/2015] [Indexed: 12/20/2022]
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148
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Bujdáková H. Management of Candida biofilms: state of knowledge and new options for prevention and eradication. Future Microbiol 2016; 11:235-51. [PMID: 26849383 DOI: 10.2217/fmb.15.139] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Biofilms formed by Candida species (spp.) on medical devices represent a potential health risk. The focus of current research is searching for new options for the treatment and prevention of biofilm-associated infections using different approaches including modern nanotechnology. This review summarizes current information concerning the most relevant resistance/tolerance mechanisms to conventional drugs and a role of additional factors contributing to these phenomena in Candida spp. (mostly Candida albicans). Additionally, it provides an information update in prevention and eradication of a Candida biofilm including experiences with 'lock' therapy, potential utilization of small molecules in biomedical applications, and perspectives of using photodynamic inactivation in the control of a Candida biofilm.
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Affiliation(s)
- Helena Bujdáková
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology & Virology, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovak Republic
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149
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Pesee S, Angkananuwat C, Tancharoensukjit S, Muanmai S, Sirivan P, Bubphawas M, Tanarerkchai N. In vitroactivity of Caspofungin combined with Fluconazole on mixedCandida albicansandCandida glabratabiofilm. Med Mycol 2016; 54:384-93. [DOI: 10.1093/mmy/myv108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/30/2015] [Indexed: 12/16/2022] Open
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150
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Salvatori O, Puri S, Tati S, Edgerton M. Innate Immunity and Saliva in Candida albicans-mediated Oral Diseases. J Dent Res 2016; 95:365-71. [PMID: 26747422 DOI: 10.1177/0022034515625222] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals.
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Affiliation(s)
- O Salvatori
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, NY, USA
| | - S Puri
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, NY, USA
| | - S Tati
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, NY, USA
| | - M Edgerton
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, NY, USA
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