551
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Finkel JS, Xu W, Huang D, Hill EM, Desai JV, Woolford CA, Nett JE, Taff H, Norice CT, Andes DR, Lanni F, Mitchell AP. Portrait of Candida albicans adherence regulators. PLoS Pathog 2012; 8:e1002525. [PMID: 22359502 PMCID: PMC3280983 DOI: 10.1371/journal.ppat.1002525] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 12/21/2011] [Indexed: 12/20/2022] Open
Abstract
Cell-substrate adherence is a fundamental property of microorganisms that enables them to exist in biofilms. Our study focuses on adherence of the fungal pathogen Candida albicans to one substrate, silicone, that is relevant to device-associated infection. We conducted a mutant screen with a quantitative flow-cell assay to identify thirty transcription factors that are required for adherence. We then combined nanoString gene expression profiling with functional analysis to elucidate relationships among these transcription factors, with two major goals: to extend our understanding of transcription factors previously known to govern adherence or biofilm formation, and to gain insight into the many transcription factors we identified that were relatively uncharacterized, particularly in the context of adherence or cell surface biogenesis. With regard to the first goal, we have discovered a role for biofilm regulator Bcr1 in adherence, and found that biofilm regulator Ace2 is a major functional target of chromatin remodeling factor Snf5. In addition, Bcr1 and Ace2 share several target genes, pointing to a new connection between them. With regard to the second goal, our findings reveal existence of a large regulatory network that connects eleven adherence regulators, the zinc-response regulator Zap1, and approximately one quarter of the predicted cell surface protein genes in this organism. This limited yet sensitive glimpse of mutant gene expression changes had thus defined one of the broadest cell surface regulatory networks in C. albicans.
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Affiliation(s)
- Jonathan S. Finkel
- 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
| | - David Huang
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Elizabeth M. Hill
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Jigar V. Desai
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Carol A. Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Jeniel E. Nett
- Department of Medicine, Section of Infectious Diseases, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Heather Taff
- Department of Medicine, Section of Infectious Diseases, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Carmelle T. Norice
- Department of Microbiology, Columbia University, New York, New York, United States of America
| | - David R. Andes
- Department of Medicine, Section of Infectious Diseases, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Aaron P. Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
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552
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Abstract
Candida grows on devices producing treatment resistant biofilms. A key tool for the study of biofilms includes an accurate assessment of viable cell growth. This study systematically tested seven techniques, among which the XTT assay provided the most reproducible, accurate, and efficient method for the quantitative estimation of C. albicans biofilms.
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Affiliation(s)
| | - Jeniel E. Nett
- Department of Microbiology and Immunology, Wisconsin, USA
- Department of William S. Middleton Veterans Hospital, Wisconsin, USA
| | - David R. Andes
- Department of Microbiology and Immunology, Wisconsin, USA
- Department of Medicine, University of Wisconsin, Wisconsin, USA
- Department of William S. Middleton Veterans Hospital, Wisconsin, USA
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553
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Nobile CJ, Fox EP, Nett JE, Sorrells TR, Mitrovich QM, Hernday AD, Tuch BB, Andes DR, Johnson AD. A recently evolved transcriptional network controls biofilm development in Candida albicans. Cell 2012; 148:126-38. [PMID: 22265407 PMCID: PMC3266547 DOI: 10.1016/j.cell.2011.10.048] [Citation(s) in RCA: 504] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 08/09/2011] [Accepted: 10/18/2011] [Indexed: 10/14/2022]
Abstract
A biofilm is an organized, resilient group of microbes in which individual cells acquire properties, such as drug resistance, that are distinct from those observed in suspension cultures. Here, we describe and analyze the transcriptional network controlling biofilm formation in the pathogenic yeast Candida albicans, whose biofilms are a major source of medical device-associated infections. We have combined genetic screens, genome-wide approaches, and two in vivo animal models to describe a master circuit controlling biofilm formation, composed of six transcription regulators that form a tightly woven network with ∼1,000 target genes. Evolutionary analysis indicates that the biofilm network has rapidly evolved: genes in the biofilm circuit are significantly weighted toward genes that arose relatively recently with ancient genes being underrepresented. This circuit provides a framework for understanding many aspects of biofilm formation by C. albicans in a mammalian host. It also provides insights into how complex cell behaviors can arise from the evolution of transcription circuits.
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Affiliation(s)
- Clarissa J Nobile
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94102, USA.
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554
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Pereira Gonzales F, Maisch T. Photodynamic inactivation for controlling Candida albicans infections. Fungal Biol 2012; 116:1-10. [DOI: 10.1016/j.funbio.2011.10.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 10/07/2011] [Accepted: 10/10/2011] [Indexed: 01/04/2023]
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555
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Abstract
Candida frequently grows as a biofilm, or an adherent community of cells protected from both the host immune system and antimicrobial therapies. Biofilms represent the predominant mode of growth for many clinical infections, including those associated with placement of a medical device. Here, we describe a model for Candida biofilm infection of one important clinical niche, a venous catheter. This animal model system incorporates the anatomical site, immune components, and fluid dynamics of a patient venous catheter infection and can be used for study of biofilm formation, drug resistance, and gene expression.
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Affiliation(s)
- Jeniel E. Nett
- University of Wisconsin, MFCB 1685 Highland Ave, Madison, WI 53705, Phone: 608-263-1545
| | - Karen Marchillo
- University of Wisconsin, MFCB 1685 Highland Ave, Madison, WI 53705, Phone: 608-263-1545
| | - David R. Andes
- University of Wisconsin, MFCB 1685 Highland Ave, Madison, WI 53705, Phone: 608-263-1545
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556
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Springer J, Chatterjee S. Candida albicans Prosthetic Shoulder Joint Infection in a Patient With Rheumatoid Arthritis on Multidrug Therapy. J Clin Rheumatol 2012; 18:52-3. [DOI: 10.1097/rhu.0b013e31823ed485] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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557
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Sganga G. Invasive fungal infections: therapeutic decision making in real life case studies. Discussion. Mycoses 2011; 54 Suppl 4:31-3. [PMID: 22126529 DOI: 10.1111/j.1439-0507.2011.02142.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Gabriele Sganga
- Department of Surgery, Division of General Surgery and Organ Transplantation, Catholic University, Rome, Italy.
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558
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Nett JE, Sanchez H, Cain MT, Ross KM, Andes DR. Interface of Candida albicans biofilm matrix-associated drug resistance and cell wall integrity regulation. EUKARYOTIC CELL 2011; 10:1660-9. [PMID: 21666076 PMCID: PMC3232725 DOI: 10.1128/ec.05126-11] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 06/01/2011] [Indexed: 01/12/2023]
Abstract
Candida albicans frequently infects medical devices by growing as a biofilm, i.e., a community of adherent organisms entrenched in an extracellular matrix. During biofilm growth, Candida spp. acquire the ability to resist high concentrations of antifungal drugs. One recently recognized biofilm resistance mechanism involves drug sequestration by matrix β-1,3 glucan. Using a candidate gene approach, we investigated potential C. albicans β-1,3-glucan regulators, based on their homology to Saccharomyces cerevisiae, including SMI1 and protein kinase C (PKC) pathway components. We identified a role for the SMI1 in biofilm matrix glucan production and development of the associated drug resistance phenotype. This pathway appears to act through transcription factor Rlmp and glucan synthase Fks1p. The phenotypes of these mutant biofilms mimicked those of the smi1Δ/smi1Δ biofilm, and overexpression of FKS1 in the smi1Δ/smi1Δ mutant restored the biofilm resistant phenotype. However, control of this pathway is distinct from that of the upstream PKC pathway because the pkc1Δ/pkc1Δ, bck1Δ/bck1Δ, mkk2Δ/mkk2Δ, and mkc1Δ/mkc1Δ biofilms retained the resistant phenotype of the parent strain. In addition, resistance to cell-perturbing agents and gene expression data do not support a significant role for the cell wall integrity pathway during the biofilm formation. Here we show that Smi1p functions in conjunction with Rlm1p and Fks1p to produce drug-sequestering biofilm β-glucan. Our work provides new insight into how the C. albicans biofilm matrix production and drug resistance pathways intersect with the planktonic cell wall integrity pathway. This novel connection helps explain how pathogens in a multicellular biofilm community are protected from anti-infective therapy.
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Affiliation(s)
- Jeniel E. Nett
- Department of Medicine
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin
| | | | | | | | - David R. Andes
- Department of Medicine
- Department of Medical Microbiology and Immunology, University of Wisconsin
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559
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Candida biofilms and the host: models and new concepts for eradication. Int J Microbiol 2011; 2012:845352. [PMID: 22164167 PMCID: PMC3227478 DOI: 10.1155/2012/845352] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Accepted: 09/30/2011] [Indexed: 02/04/2023] Open
Abstract
Biofilms define mono- or multispecies communities embedded in a self-produced protective matrix, which is strongly attached to surfaces. They often are considered a general threat not only in industry but also in medicine. They constitute a permanent source of contamination, and they can disturb the proper usage of the material onto which they develop. This paper relates to some of the most recent approaches that have been elaborated to eradicate Candida biofilms, based on the vast effort put in ever-improving models of biofilm formation in vitro and in vivo, including novel flow systems, high-throughput techniques and mucosal models. Mixed biofilms, sustaining antagonist or beneficial cooperation between species, and their interplay with the host immune system are also prevalent topics. Alternative strategies against biofilms include the lock therapy and immunotherapy approaches, and material coating and improvements. The host-biofilm interactions are also discussed, together with their potential applications in Candida biofilm elimination.
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560
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Dworniczek* E, Franiczek R, Nawrot U, Gościniak G. Interactions of Bacteria and Fungi at the Surface. BIOLOGICAL INTERACTIONS WITH SURFACE CHARGE IN BIOMATERIALS 2011. [DOI: 10.1039/9781849733366-00148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The increased life span of humans and the dynamic development of Biomaterials' industry have led to widespread use of implants in modern medicine. Microorganisms, mostly opportunistic flora,are able to adapt perfectly to the changing environment of their host. Bacteria, once regarded as non-pathogenic, successfully bind to artificial surfaces resulting in diseases that are difficult to treat. The Chapter discusses the process of microbial adhesion to the surfaces. It provides the brief description of the most important infections of humans, which result from the microbial colonization of implanted biomaterials. This adhesion is characterized in the context of physicochemical and biological interactions between microorganism and the surface. We describe the effects of environmental factors and the contribution of bacterial/fungal cell structures on microbial adhesion. Finally, the Chapter presents the most important aspects of interactions between bacteria and charged surfaces.
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Affiliation(s)
- E. Dworniczek*
- Wrocław Medical University Department of Microbiology, Chałubiński Street 4, Wrocław, 50-368, Poland
| | - R. Franiczek
- Wrocław Medical University Department of Microbiology, Chałubiński Street 4, Wrocław, 50-368, Poland
| | - U. Nawrot
- Wrocław Medical University Department of Microbiology, Chałubiński Street 4, Wrocław, 50-368, Poland
| | - G. Gościniak
- Wrocław Medical University Department of Microbiology, Chałubiński Street 4, Wrocław, 50-368, Poland
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561
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Baradkar VP, Mathur M, Sonavane A, Kumar S. Candidal infections of ventriculoperitoneal shunts. J Pediatr Neurosci 2011; 4:73-5. [PMID: 21887187 PMCID: PMC3162793 DOI: 10.4103/1817-1745.57325] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Although ventriculoperitoneal (VP) shunt infection is a common complication of shunt procedures, fungal infection is considered to be rare. In the present study, we performed retrospective analysis of six cases in which candida infection occurred. In all these six cases, VP shunt was performed in children for hydrocephalus and the onset of symptoms varied between seven days to one month after the surgical procedure was performed. The commonest clinical signs and symptoms were fever (100%), vomiting (100%), and altered sensorium (50%). The commonest isolate was Candida albicans (66.66%) followed by Candida parapsilosis and Candida glabrata in one case each. All the patients were successfully treated with Amphotericin B and there was no mortality recorded.
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Affiliation(s)
- V P Baradkar
- Department of Microbiology, Lokmanya Tilak Municipal Medical College and General Hospital, Sion, Mumbai - 400 002, India
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562
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Negri M, Silva S, Henriques M, Oliveira R. Insights into Candida tropicalis nosocomial infections and virulence factors. Eur J Clin Microbiol Infect Dis 2011; 31:1399-412. [PMID: 22037823 DOI: 10.1007/s10096-011-1455-z] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 10/08/2011] [Indexed: 12/31/2022]
Abstract
Candida tropicalis is considered the first or the second non-Candida albicans Candida (NCAC) species most frequently isolated from candidosis, mainly in patients admitted in intensive care units (ICUs), especially with cancer, requiring prolonged catheterization, or receiving broad-spectrum antibiotics. The proportion of candiduria and candidemia caused by C. tropicalis varies widely with geographical area and patient group. Actually, in certain countries, C. tropicalis is more prevalent, even compared with C. albicans or other NCAC species. Although prophylactic treatments with fluconazole cause a decrease in the frequency of candidosis caused by C. tropicalis, it is increasingly showing a moderate level of fluconazole resistance. The propensity of C. tropicalis for dissemination and the high mortality associated with its infections might be strongly related to the potential of virulence factors exhibited by this species, such as adhesion to different host surfaces, biofilm formation, infection and dissemination, and enzymes secretion. Therefore, the aim of this review is to outline the present knowledge on all the above-mentioned C. tropicalis virulence traits.
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Affiliation(s)
- M Negri
- Institute for Biotechnology and Bioengineering (IBB), Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
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563
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Roles of Ras1 membrane localization during Candida albicans hyphal growth and farnesol response. EUKARYOTIC CELL 2011; 10:1473-84. [PMID: 21908593 DOI: 10.1128/ec.05153-11] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many Ras GTPases localize to membranes via C-terminal farnesylation and palmitoylation, and localization regulates function. In Candida albicans, a fungal pathogen of humans, Ras1 links environmental cues to morphogenesis. Here, we report the localization and membrane dynamics of Ras1, and we characterize the roles of conserved C-terminal cysteine residues, C287 and C288, which are predicted sites of palmitoylation and farnesylation, respectively. GFP-Ras1 is localized uniformly to plasma membranes in both yeast and hyphae, yet Ras1 plasma membrane mobility was reduced in hyphae compared to that in yeast. Ras1-C288S was mislocalized to the cytoplasm and could not support hyphal development. Ras1-C287S was present primarily on endomembranes, and strains expressing ras1-C287S were delayed or defective in hyphal induction depending on the medium used. Cells bearing constitutively activated Ras1-C287S or Ras1-C288S, due to a G13V substitution, showed increased filamentation, suggesting that lipid modifications are differentially important for Ras1 activation and effector interactions. The C. albicans autoregulatory molecule, farnesol, inhibits Ras1 signaling through adenylate cyclase and bears structural similarities to the farnesyl molecule that modifies Ras1. At lower concentrations of farnesol, hyphal growth was inhibited but Ras1 plasma membrane association was not altered; higher concentrations of farnesol led to mislocalization of Ras1 and another G protein, Rac1. Furthermore, farnesol inhibited hyphal growth mediated by cytosolic Ras1-C288SG13V, suggesting that farnesol does not act through mechanisms that depend on Ras1 farnesylation. Our findings imply that Ras1 is farnesylated and palmitoylated, and that the Ras1 stimulation of adenylate cyclase-dependent phenotypes can occur in the absence of these lipid modifications.
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564
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Robbins N, Uppuluri P, Nett J, Rajendran R, Ramage G, Lopez-Ribot JL, Andes D, Cowen LE. Hsp90 governs dispersion and drug resistance of fungal biofilms. PLoS Pathog 2011; 7:e1002257. [PMID: 21931556 PMCID: PMC3169563 DOI: 10.1371/journal.ppat.1002257] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 07/27/2011] [Indexed: 01/12/2023] Open
Abstract
Fungal biofilms are a major cause of human mortality and are recalcitrant to most treatments due to intrinsic drug resistance. These complex communities of multiple cell types form on indwelling medical devices and their eradication often requires surgical removal of infected devices. Here we implicate the molecular chaperone Hsp90 as a key regulator of biofilm dispersion and drug resistance. We previously established that in the leading human fungal pathogen, Candida albicans, Hsp90 enables the emergence and maintenance of drug resistance in planktonic conditions by stabilizing the protein phosphatase calcineurin and MAPK Mkc1. Hsp90 also regulates temperature-dependent C. albicans morphogenesis through repression of cAMP-PKA signalling. Here we demonstrate that genetic depletion of Hsp90 reduced C. albicans biofilm growth and maturation in vitro and impaired dispersal of biofilm cells. Further, compromising Hsp90 function in vitro abrogated resistance of C. albicans biofilms to the most widely deployed class of antifungal drugs, the azoles. Depletion of Hsp90 led to reduction of calcineurin and Mkc1 in planktonic but not biofilm conditions, suggesting that Hsp90 regulates drug resistance through different mechanisms in these distinct cellular states. Reduction of Hsp90 levels led to a marked decrease in matrix glucan levels, providing a compelling mechanism through which Hsp90 might regulate biofilm azole resistance. Impairment of Hsp90 function genetically or pharmacologically transformed fluconazole from ineffectual to highly effective in eradicating biofilms in a rat venous catheter infection model. Finally, inhibition of Hsp90 reduced resistance of biofilms of the most lethal mould, Aspergillus fumigatus, to the newest class of antifungals to reach the clinic, the echinocandins. Thus, we establish a novel mechanism regulating biofilm drug resistance and dispersion and that targeting Hsp90 provides a much-needed strategy for improving clinical outcome in the treatment of biofilm infections. Candida albicans and Aspergillus fumigatus are the most common causative agents of fungal infections worldwide. Both species can form biofilms on host tissues and indwelling medical devices that are highly resistant to antifungal treatment. Here we implicate the molecular chaperone Hsp90 as a key regulator of biofilm dispersion and drug resistance. Compromising Hsp90 function reduced biofilm formation of C. albicans in vitro and impaired dispersal of biofilm cells, potentially blocking their capacity to serve as reservoirs for infection. Further, compromise of Hsp90 function abrogated resistance of C. albicans biofilms to the most widely deployed class of antifungal, the azoles, both in vitro and in a mammalian model of catheter-associated candidiasis. Key drug resistance regulators were depleted upon reduction of Hsp90 levels in planktonic but not biofilm conditions, suggesting that Hsp90 regulates drug resistance through different mechanisms in these distinct cellular states. Reduction of Hsp90 markedly reduced levels of matrix glucan, a carbohydrate important for C. albicans biofilm drug resistance. Inhibition of Hsp90 also reduced resistance of A. fumigatus biofilms to the newest class of antifungal, the echinocandins. Thus, targeting Hsp90 provides a promising strategy for the treatment of biofilm infections caused by diverse fungal species.
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Affiliation(s)
- Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Priya Uppuluri
- Department of Biology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, Texas, United States of America
| | - Jeniel Nett
- Department of Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Ranjith Rajendran
- College of Medicine, Veterinary and Life Science, University of Glasgow, Glasgow, United Kingdom
| | - Gordon Ramage
- College of Medicine, Veterinary and Life Science, University of Glasgow, Glasgow, United Kingdom
| | - Jose L. Lopez-Ribot
- Department of Biology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, Texas, United States of America
| | - David Andes
- Department of Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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565
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Grald A, Yargosz P, Case S, Shea K, Johnson DI. Small-molecule inhibitors of biofilm formation in laboratory and clinical isolates of Candida albicans. J Med Microbiol 2011; 61:109-114. [PMID: 21903824 DOI: 10.1099/jmm.0.034124-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Candida albicans cells have the ability to form biofilms on biotic and abiotic surfaces, such as indwelling medical devices. C. albicans cells can interconvert between budded and hyphal growth forms, herein termed the budded-to-hyphal transition (BHT), which is important for the formation of mature biofilms. Previous work identified 23 small organic molecules that could inhibit the BHT but did not affect C. albicans cell viability or budded cell growth. These BHT inhibitors were proposed to inhibit multiple signalling pathways regulating the BHT, many of which also regulate biofilm formation. However, only three of the BHT inhibitors, buhytrinA, ETYA and CGP-37157, were capable of inhibiting in vitro biofilm formation of wild-type laboratory C. albicans strains. When clinical C. albicans isolates were examined for their ability to form biofilms, only 11 of the 28 clinical isolates tested (39%) were capable of forming biofilms. Although buhytrinA, ETYA and CGP-37157 could inhibit the BHT of all 28 clinical isolates, they were only able to inhibit biofilm formation of a subset of these clinical isolates, with ETYA having 100% efficacy. These data indicate that the biofilm-forming capability of laboratory and clinical isolates of C. albicans, as well as the efficacy of BHT inhibitors against these different isolates, can differ dramatically. These differences between laboratory and clinical isolates should be an important aspect to consider when examining potentially new antifungal therapeutics.
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Affiliation(s)
- Ariel Grald
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Philip Yargosz
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Samantha Case
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Katelyn Shea
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Douglas I Johnson
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
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566
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Harriott MM, Noverr MC. Importance of Candida-bacterial polymicrobial biofilms in disease. Trends Microbiol 2011; 19:557-63. [PMID: 21855346 DOI: 10.1016/j.tim.2011.07.004] [Citation(s) in RCA: 219] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/30/2011] [Accepted: 07/21/2011] [Indexed: 12/15/2022]
Abstract
Candida albicans is the most prevalent human fungal pathogen, with an ability to inhabit diverse host niches and cause disease in both immunocompetent and immunocompromised individuals. C. albicans also readily forms biofilms on indwelling medical devices and mucosal tissues, which serve as an infectious reservoir that is difficult to eradicate, and can lead to lethal systemic infections. Biofilm formation occurs within a complex milieu of host factors and other members of the human microbiota. Polymicrobial interactions will probably dictate the cellular and biochemical composition of the biofilm, as well as influence clinically relevant outcomes, such as drug and host resistance and virulence. In this manuscript, we review C. albicans infections in the context of in vivo polymicrobial biofilms and implications for pathogenesis.
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Affiliation(s)
- Melphine M Harriott
- Department of Medicine, Division of Infectious Diseases, Henry Ford Hospital, Detroit, MI 48202, USA
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567
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DiDone L, Oga D, Krysan DJ. A novel assay of biofilm antifungal activity reveals that amphotericin B and caspofungin lyse Candida albicans cells in biofilms. Yeast 2011; 28:561-8. [DOI: 10.1002/yea.1860] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/07/2011] [Indexed: 11/11/2022] Open
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568
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Estivill D, Arias A, Torres-Lana A, Carrillo-Muñoz AJ, Arévalo MP. Biofilm formation by five species of Candida on three clinical materials. J Microbiol Methods 2011; 86:238-42. [PMID: 21664387 DOI: 10.1016/j.mimet.2011.05.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/15/2011] [Accepted: 05/26/2011] [Indexed: 10/18/2022]
Abstract
Most recalcitrant infections are associated with colonization and microbial biofilm development. These biofilms are difficult to eliminate by the immune response mechanisms and the current antimicrobial. Fungi can form biofilms on biomaterials commonly used in clinical practice (intravascular catheters, dentures, heart valves, implanted devices, contact lenses and other devices) and are associated with infections. A variety of in vitro models using different substrates/devices have been described. These models have been used to investigate the effect of different variables, including flow, growth time, nutrients and physiological conditions on fungal biofilm formation, morphology and architecture. The purpose of our study is to analyze biofilm formation capacity by 84 strains of Candida spp. (23C. albicans, 23C. parapsilosis, 16C. tropicalis, 17C. glabrata and 5C. krusei) on three materials used in medical devices and its quantification using a method based on viable cell count. Under the conditions of our study, all assayed Candida strains have been able to form biofilms. All species showed greater biofilm formation capacity on Teflon™, with the exception of C. glabrata which displayed higher biofilm formation capacity on PVC. Biofilm formation by Candida spp. varies depending on the type of material on which it grows and on the species and strain of Candida. The method we propose could be of great use to deepen scientific knowledge on this subject of remarkable clinical significance, considering the absence of standard biofilm formation and quantification techniques on the catheters and the level of difficulty associated to those available.
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Affiliation(s)
- D Estivill
- Althaia, Hospital Sant Joan de Déu, Manresa, Barcelona, Spain
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569
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O’Brien D, Stevens NT, Lim CH, O’Brien DF, Smyth E, Fitzpatrick F, Humphreys H. Candida infection of the central nervous system following neurosurgery: a 12-year review. Acta Neurochir (Wien) 2011; 153:1347-50. [PMID: 21431456 DOI: 10.1007/s00701-011-0990-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 03/01/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Candida infection of the central nervous system (CNS) following neurosurgery is relatively unusual but is associated with significant morbidity and mortality. We present our experience with this infection in adults and discuss clinical characteristics, treatment options, and outcome. METHODS All episodes of Candida isolated from the central nervous system were identified by searching our laboratory database. Review of the cases was performed by means of a retrospective chart review. RESULTS Eleven episodes of Candida CSF infection following neurosurgery were identified over a 12-year period. Candida albicans was the predominant species isolated (n = 8, 73%). All infections were associated with foreign intracranial material, nine with external ventricular drains (82%), one with a ventriculoperitoneal shunt, one with a lumbar drain, and one with Gliadel wafers (1,3-bis [2-chloroethyl]-1-nitrosurea). Fluconazole or liposomal amphotericin B were the most common anti-fungal agents used. The mortality rate identified in our series was 27%. CONCLUSIONS Candida infection following neurosurgery remains a relatively rare occurrence but one that causes significant mortality. These are complex infections, the management of which benefits from a close liaison between the clinical microbiologist and neurosurgeon. Prompt initiation of antifungal agents and removal of infected devices offers the best hope of a cure.
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570
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Thevissen K, Pellens K, De Brucker K, François IE, Chow KK, Meert EM, Meert W, Van Minnebruggen G, Borgers M, Vroome V, Levin J, De Vos D, Maes L, Cos P, Cammue BP. Novel fungicidal benzylsulfanyl-phenylguanidines. Bioorg Med Chem Lett 2011; 21:3686-92. [DOI: 10.1016/j.bmcl.2011.04.075] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/13/2011] [Accepted: 04/19/2011] [Indexed: 10/18/2022]
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571
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Brückner S, Mösch HU. Choosing the right lifestyle: adhesion and development in Saccharomyces cerevisiae. FEMS Microbiol Rev 2011; 36:25-58. [PMID: 21521246 DOI: 10.1111/j.1574-6976.2011.00275.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The budding yeast Saccharomyces cerevisiae is a eukaryotic microorganism that is able to choose between different unicellular and multicellular lifestyles. The potential of individual yeast cells to switch between different growth modes is advantageous for optimal dissemination, protection and substrate colonization at the population level. A crucial step in lifestyle adaptation is the control of self- and foreign adhesion. For this purpose, S. cerevisiae contains a set of cell wall-associated proteins, which confer adhesion to diverse biotic and abiotic surfaces. Here, we provide an overview of different aspects of S. cerevisiae adhesion, including a detailed description of known lifestyles, recent insights into adhesin structure and function and an outline of the complex regulatory network for adhesin gene regulation. Our review shows that S. cerevisiae is a model system suitable for studying not only the mechanisms and regulation of cell adhesion, but also the role of this process in microbial development, ecology and evolution.
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Affiliation(s)
- Stefan Brückner
- Department of Genetics, Philipps-Universität Marburg, Marburg, Germany
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572
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Quiles-Melero I, García-Rodríguez J, Gómez-López A, Mingorance J. Evaluation of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry for identification of Candida parapsilosis, C. orthopsilosis and C. metapsilosis. Eur J Clin Microbiol Infect Dis 2011; 31:67-71. [DOI: 10.1007/s10096-011-1277-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/13/2011] [Indexed: 11/28/2022]
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573
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Yilmaz M, Mete B, Ozaras R, Kaynak G, Tabak F, Tenekecioğlu Y, Oztürk R. Aspergillus fumigatus infection as a delayed manifestation of prosthetic knee arthroplasty and a review of the literature. ACTA ACUST UNITED AC 2011; 43:573-8. [PMID: 21526903 DOI: 10.3109/00365548.2011.574294] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Fungal infection after total joint arthroplasty is a very rare but serious complication and a challenge to the treating and consulting physicians. The literature includes little information about the treatment protocol for Aspergillus infection after total knee arthroplasty, since only 3 cases have been reported. We describe the case of a non-immunocompromised patient who lacked predisposing risk factors and presented with pain and swelling. An aspiration under sterile conditions revealed Aspergillus fumigatus. The patient was treated successfully with a 2-stage exchange reimplantation and 6-week course of liposomal amphotericin B. At 4 y after reimplantation, the patient had no evidence of infection or pain.
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Affiliation(s)
- Mesut Yilmaz
- Department of Infectious Diseases and Clinical Microbiology, Istanbul Medipol University, Istanbul, Turkey.
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574
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Srinivasan A, Uppuluri P, Lopez-Ribot J, Ramasubramanian AK. Development of a high-throughput Candida albicans biofilm chip. PLoS One 2011; 6:e19036. [PMID: 21544190 PMCID: PMC3081316 DOI: 10.1371/journal.pone.0019036] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 03/16/2011] [Indexed: 01/20/2023] Open
Abstract
We have developed a high-density microarray platform consisting of nano-biofilms of Candida albicans. A robotic microarrayer was used to print yeast cells of C. albicans encapsulated in a collagen matrix at a volume as low as 50 nL onto surface-modified microscope slides. Upon incubation, the cells grow into fully formed “nano-biofilms”. The morphological and architectural complexity of these biofilms were evaluated by scanning electron and confocal scanning laser microscopy. The extent of biofilm formation was determined using a microarray scanner from changes in fluorescence intensities due to FUN 1 metabolic processing. This staining technique was also adapted for antifungal susceptibility testing, which demonstrated that, similar to regular biofilms, cells within the on-chip biofilms displayed elevated levels of resistance against antifungal agents (fluconazole and amphotericin B). Thus, results from structural analyses and antifungal susceptibility testing indicated that despite miniaturization, these biofilms display the typical phenotypic properties associated with the biofilm mode of growth. In its final format, the C. albicans biofilm chip (CaBChip) is composed of 768 equivalent and spatially distinct nano-biofilms on a single slide; multiple chips can be printed and processed simultaneously. Compared to current methods for the formation of microbial biofilms, namely the 96-well microtiter plate model, this fungal biofilm chip has advantages in terms of miniaturization and automation, which combine to cut reagent use and analysis time, minimize labor intensive steps, and dramatically reduce assay costs. Such a chip should accelerate the antifungal drug discovery process by enabling rapid, convenient and inexpensive screening of hundreds-to-thousands of compounds simultaneously.
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Affiliation(s)
- Anand Srinivasan
- Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Priya Uppuluri
- Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
- Department of South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Jose Lopez-Ribot
- Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
- Department of South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, United States of America
- * E-mail: (JL); (AKR)
| | - Anand K. Ramasubramanian
- Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, Texas, United States of America
- Department of South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, United States of America
- * E-mail: (JL); (AKR)
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575
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Silva S, Negri M, Henriques M, Oliveira R, Williams DW, Azeredo J. Adherence and biofilm formation of non-Candida albicans Candida species. Trends Microbiol 2011; 19:241-7. [PMID: 21411325 DOI: 10.1016/j.tim.2011.02.003] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 02/03/2011] [Accepted: 02/09/2011] [Indexed: 11/26/2022]
Abstract
Most cases of candidosis have been attributed to Candida albicans, but recently non-C. albicans Candida species have been identified as frequent human pathogens. Candida pathogenicity has been attributed to several factors, including adhesion to medical devices and/or host cells, biofilm formation, and secretion of hydrolytic enzymes (proteases, phospholipases and haemolysins). Although 'new'Candida species are emerging, there is still a lack of information about their pathogenicity. This review discusses recent advances in our knowledge of Candida glabrata, Candida parapsilosis and Candida tropicalis virulence factors, specifically those of adhesion and biofilm formation, which are key components in Candida pathogenicity.
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Affiliation(s)
- Sónia Silva
- Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar 4710-057, Braga, Portugal
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576
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Activities of triazole-echinocandin combinations against Candida species in biofilms and as planktonic cells. Antimicrob Agents Chemother 2011; 55:1968-74. [PMID: 21343465 DOI: 10.1128/aac.00959-10] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biofilm formation complicates the treatment of various infections caused by Candida species. We investigated the effects of simultaneous or sequential combinations of two triazoles, voriconazole (VRC) and posaconazole (PSC), with two echinocandins, anidulafungin (AND) and caspofungin (CAS), against Candida albicans and Candida parapsilosis biofilms in comparison to their planktonic counterparts. Antifungal activity was assessed by the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]2H-tetrazolium-5-carboxanilide (XTT) metabolic assay. Antifungal-agent interactions were analyzed by the Bliss independence model in the simultaneous-treatment studies and by analysis of variance (ANOVA) in the sequential-treatment studies. Against C. albicans planktonic cells, the simultaneous combination of PSC (32 to 128 mg/liter) and CAS (0.008 to 0.25 mg/liter) was synergistic; the combinations of PSC (128 to 1,024 mg/liter) with AND (0.03 to 0.5 mg/liter) and VRC (32 to 512 mg/liter) with AND (0.008 to 0.03 mg/liter) were antagonistic. Against C. parapsilosis planktonic cells, the interaction between VRC (32 to 1,024 mg/liter) and CAS (1 to 16 mg/liter) was antagonistic. All simultaneous antifungal combinations demonstrated indifferent interactions against biofilms of both Candida species. Damage to biofilms of both species increased (P<0.01) in the presence of subinhibitory concentrations of echinocandins (0.008 to 0.064 mg/liter), followed by the addition of PSC (512 mg/liter for C. albicans and 64 to 512 mg/liter for C. parapsilosis) or VRC (256 to 512 mg/liter for C. albicans and 512 mg/liter for C. parapsilosis). Triazole-echinocandin combinations do not appear to produce antagonistic effects against Candida sp. biofilms, while various significant interactions occur with their planktonic counterparts.
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577
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Öncü S. In vitro effectiveness of antifungal lock solutions on catheters infected with Candida species. J Infect Chemother 2011; 17:634-9. [PMID: 21327934 DOI: 10.1007/s10156-011-0224-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 01/14/2011] [Indexed: 10/18/2022]
Abstract
The antibiotic lock technique involves filling the catheter lumen with an antibiotic solution and allowing it to dwell for sufficient time to sterilize the infected device. However, antifungal therapy for treating catheter-related fungal infection in this setting is unknown. In this study, the effectiveness of the commercially available antifungal drugs, which are commonly used in candidemia, were assessed in an in vitro antibiotic lock model. Amphotericin B, caspofungin, fluconazole, itraconazole, and voriconazole were used as lock solutions against catheters infected with slime-forming Candida albicans and Candida parapsilosis. Infected catheters were exposed to each of the antifungal lock solution (300-, 500- and 1,000-fold MIC) for 1, 3, 5, and 7 days. The presence of the remaining Candida in the catheter was evaluated quantitatively. Among the antifungal agents, amphotericin B and caspofungin lock solutions decreased the yeast colony count significantly from baseline starting on the first day of treatment (P < 0.001). Significant decrease in the colony count continued, and the catheters were completely sterile at the fifth day. Fluconazole, itraconazole, and voriconazole lock solutions failed to sterilize the catheters, and the numbers of yeast colonies were >10(5) at the end of the study. In summary, amphotericin B and caspofungin appear to have unique activities against Candida-infected catheters. It seems that one of these drugs may permit the retention of an affected intravascular catheter by sterilizing it in a few days.
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Affiliation(s)
- Serkan Öncü
- Department of Infectious Diseases and Clinical Microbiology, Adnan Menderes University Medical Faculty, 09100 Aydin, Turkey.
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578
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Liu KH, Yeh YL, Shen WC. Fast preparation of fungal DNA for PCR screening. J Microbiol Methods 2011; 85:170-2. [PMID: 21315113 DOI: 10.1016/j.mimet.2011.01.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 01/30/2011] [Accepted: 01/31/2011] [Indexed: 11/17/2022]
Abstract
Rapid DNA preparation for the quick screening is highly demanded in diverse research fields. Here, we combined an extraction buffer and heat treatment to generate DNA templates from yeast and filamentous fungal materials for PCR. This method may be widely applicable to diverse fungal species in clinical and basic studies.
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Affiliation(s)
- Kuang-Hung Liu
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
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579
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Ortega M, Marco F, Soriano A, Almela M, Martínez J, López J, Pitart C, Mensa J. Candida species bloodstream infection: epidemiology and outcome in a single institution from 1991 to 2008. J Hosp Infect 2011; 77:157-61. [DOI: 10.1016/j.jhin.2010.09.026] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 09/10/2010] [Indexed: 11/30/2022]
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580
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LaFleur MD, Lucumi E, Napper AD, Diamond SL, Lewis K. Novel high-throughput screen against Candida albicans identifies antifungal potentiators and agents effective against biofilms. J Antimicrob Chemother 2011; 66:820-6. [PMID: 21393183 DOI: 10.1093/jac/dkq530] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVES Microbial adhesion and biofilms have important implications for human health and disease. Candida albicans is an opportunistic pathogen which forms drug-resistant biofilms that contribute to the recalcitrance of disease. We have developed a high-throughput screen for potentiators of clotrimazole, a common therapy for Candida infections, including vaginitis and thrush. The screen was performed against C. albicans biofilms grown in microtitre plates in order to target the most resilient forms of the pathogen. METHODS Biofilm growth, in individual wells of 384-well plates, was measured using the metabolic indicator alamarBlue® and found to be very consistent and reproducible. This assay was used to test the effect of more than 120 000 small molecule compounds from the NIH Molecular Libraries Small Molecule Repository, and compounds that enhanced the activity of clotrimazole or acted on the biofilms alone were identified as hits. RESULTS Nineteen compounds (0.016% hit rate) were identified and found to cause more than 30% metabolic inhibition of biofilms compared with clotrimazole alone, which had a modest effect on biofilm viability at the concentration tested. Hits were confirmed for activity against biofilms with dose-response measurements. Several compounds had increased activity in combination with clotrimazole, including a 1,3-benzothiazole scaffold that exhibited a >100-fold improvement against biofilms of three separate C. albicans isolates. Cytotoxicity experiments using human fibroblasts confirmed the presence of lead molecules with favourable antifungal activity relative to cytotoxicity. CONCLUSIONS We have validated a novel approach to identify antifungal potentiators and completed a high-throughput screen to identify small molecules with activity against C. albicans biofilms. These small molecules may specifically target the biofilm and make currently available antifungals more effective.
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Affiliation(s)
- Michael D LaFleur
- Antimicrobial Discovery Center and Department of Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02118, USA.
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581
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Wei GX, Xu X, Wu CD. In vitro synergism between berberine and miconazole against planktonic and biofilm Candida cultures. Arch Oral Biol 2011; 56:565-72. [PMID: 21272859 DOI: 10.1016/j.archoralbio.2010.11.021] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 11/20/2010] [Accepted: 11/26/2010] [Indexed: 01/28/2023]
Abstract
OBJECTIVES To investigate the antimycotic activity of the plant alkaloid berberine (BBR), alone and in combination with antifungal azoles, against planktonic and biofilm Candida cultures. DESIGN The minimum inhibitory concentrations (MICs) of BBR, miconazole (MCZ), and fluconazole (FLC) towards Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis, and Candida tropicalis were determined by a microdilution method. For C. albicans, the synergistic effects of BBR combined with MCZ or FLC were examined in a paper disc agar diffusion assay and checkerboard microdilution assay. The effect of the BBR/MCZ combination was further investigated in a C. albicans biofilm formation model with a dual-chamber flow cell. The effect on metabolic activity of biofilm cells was established using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)/menadione. RESULTS Berberine inhibited the growth of various Candida species (MICs 0.98-31.25mg/L) in the following order of susceptibility: C. krusei > C. kefyr > C. glabrata > C. tropicalis > C. parapsilosis and C. albicans. Synergism between BBR and MCZ or FLC was observed in the disc diffusion assay as well as in suspension showing an FIC index <0.5 (∑FIC=0.19). Whilst neither BBR (16 mg/L) nor MCZ (0.8 mg/L) alone significantly inhibited biofilm formation of C. albicans, their combination reduced biofilm formation by >91% after 24 h, as established from the reduction in surface area coverage (P<0.01). The BBR/MCZ combination also exhibited synergy against the metabolic activity of pre-formed C. albicans biofilms in polystyrene microtiter plates (∑FIC=0.25). CONCLUSION Berberine exhibits synergistic effects with commonly used antimycotic drugs against C. albicans, either in planktonic or in biofilm growth phases.
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Affiliation(s)
- Guo-Xian Wei
- Department of Pediatric Dentistry, University of Illinois at Chicago, College of Dentistry, MC850, Chicago, IL 60612-7212, USA
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582
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Oh BJ, Shin JH, Kim MN, Sung H, Lee K, Joo MY, Shin MG, Suh SP, Ryang DW. Biofilm formation and genotyping ofCandida haemulonii, Candida pseudohaemulonii, and a proposed new species (Candida auris) isolates from Korea. Med Mycol 2011; 49:98-102. [DOI: 10.3109/13693786.2010.493563] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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583
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Van Mulders SE, Stassen C, Daenen L, Devreese B, Siewers V, van Eijsden RGE, Nielsen J, Delvaux FR, Willaert R. The influence of microgravity on invasive growth in Saccharomyces cerevisiae. ASTROBIOLOGY 2011; 11:45-55. [PMID: 21345087 DOI: 10.1089/ast.2010.0518] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study investigates the effects of microgravity on colony growth and the morphological transition from single cells to short invasive filaments in the model eukaryotic organism Saccharomyces cerevisiae. Two-dimensional spreading of the yeast colonies grown on semi-solid agar medium was reduced under microgravity in the Σ1278b laboratory strain but not in the CMBSESA1 industrial strain. This was supported by the Σ1278b proteome map under microgravity conditions, which revealed upregulation of proteins linked to anaerobic conditions. The Σ1278b strain showed a reduced invasive growth in the center of the yeast colony. Bud scar distribution was slightly affected, with a switch toward more random budding. Together, microgravity conditions disturb spatially programmed budding patterns and generate strain-dependent growth differences in yeast colonies on semi-solid medium.
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584
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Askew C, Sellam A, Epp E, Mallick J, Hogues H, Mullick A, Nantel A, Whiteway M. The zinc cluster transcription factor Ahr1p directs Mcm1p regulation of Candida albicans adhesion. Mol Microbiol 2010; 79:940-53. [PMID: 21299649 DOI: 10.1111/j.1365-2958.2010.07504.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biofilm development by Candida albicans requires cell adhesion for the initial establishment of the biofilm and the continued stability after hyphal development occurs; however, the regulation of the process has not been fully established. Using chromatin immunoprecipitation coupled to microarray analysis (ChIP-chip) we have characterized a regulon containing the Mcm1p factor that is required for the initial surface adhesion during biofilm formation. In the yeast Saccharomyces cerevisiae several Mcm1p regulons have been characterized in which regulatory specificity is achieved through cofactors binding a sequence adjacent to the Mcm1p binding site. This new Mcm1p regulon in C. albicans also requires a cofactor, which we identify as the transcription factor Ahr1p. However, in contrast to the other yeast regulons, Ahr1p alone binds the target promoters, which include several key adhesion genes, and recruits Mcm1p to these sites. Through transcription profiling and qPCR analysis, we demonstrate that this Ahr1p-Mcm1p complex directly activates these adhesion genes. When the regulatory circuit was disrupted by deleting AHR1, the strain displayed reduced adherence to a polystyrene surface. We also demonstrate a role for the regulon in hyphal growth and in virulence. Our work thus establishes a new mechanism of Mcm1p-directed regulation distinct from those observed for other Mcm1p co-regulators.
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Affiliation(s)
- Christopher Askew
- Biotechnology Research Institute, National Research Council of Canada, Montréal, Québec, Canada H4P 2R2
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585
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Abstract
Candida species cause frequent infections owing to their ability to form biofilms - surface-associated microbial communities - primarily on implanted medical devices. Increasingly, mechanistic studies have identified the gene products that participate directly in the development of Candida albicans biofilms, as well as the regulatory circuitry and networks that control their expression and activity. These studies have uncovered new mechanisms and signals that govern C. albicans biofilm development and associated drug resistance, thus providing biological insight and therapeutic foresight.
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586
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Raut J, Rathod V, Karuppayil SM. Cell surface hydrophobicity and adhesion: a study on fifty clinical isolates of Candida albicans. ACTA ACUST UNITED AC 2010; 51:131-6. [PMID: 20716851 DOI: 10.3314/jjmm.51.131] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cell surface hydrophobicity (CSH) of 50 clinical isolates of Candida albicans was studied, and values varied broadly in the range 2% to 41%. Purpose of the present work was to investigate correlation of CSH with the C. albicans adherence to solid surfaces, if any. To elucidate this, adhesion to the polystyrene model surface was studied for all the clinical isolates. Adherence varied in the range of 79 to 478 cells per microscopic field. Results indicated no correlation between CSH of the clinical isolates and their adhesion to polystyrene.
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Affiliation(s)
- Jayant Raut
- School of Life Sciences, SRTM University, Nanded (MS), India
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587
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588
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Leonidou L, Gogos CA. Catheter-related bloodstream infections: catheter management according to pathogen. Int J Antimicrob Agents 2010; 36 Suppl 2:S26-32. [PMID: 21129929 DOI: 10.1016/j.ijantimicag.2010.11.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Central-line access is an essential part of modern healthcare practice; however, catheter-related bloodstream infection is a major problem that causes substantial morbidity and mortality, and excess length of stay and cost. The risk of infection depends on the type of device, the site of insertion, the underlying conditions and the appropriate prevention measures taken during catheter insertion. Management of catheter-related bloodstream infection involves deciding on catheter removal, antimicrobial catheter lock solution and the type and duration of systemic antimicrobial therapy. Systemic antimicrobial use is essential but, although generally effective in controlling sepsis, it often fails to sterilise the line, increasing the incidence of complications or recurrence. The decision regarding whether the catheter should be removed or retained is therefore crucial. One of the major factors to be considered is the type of organism involved in the catheter-related infection. This review outlines the epidemiology, pathogenesis, diagnosis, microbiology and management of catheter-related infections, mainly focusing on the management of the intravascular device according to the pathogen.
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Affiliation(s)
- Leonidia Leonidou
- Department of Infectious Diseases, Patras University Medical School, Patras, Greece
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589
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Uppuluri P, Lopez-Ribot JL. An easy and economical in vitro method for the formation of Candida albicans biofilms under continuous conditions of flow. Virulence 2010; 1:483-7. [PMID: 21178492 DOI: 10.4161/viru.1.6.13186] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Candida albicans can develop biofilms on medical devices and these biofilms are most often nourished by a continuous flow of body fluids and subjected to shear stress forces. While many C. albicans biofilm studies have been carried out using in vitro static models, more limited information is available for biofilms developed under conditions of flow. We have previously described a simple flow biofilm model (SFB) for the development of C. albicans biofilms under conditions of continuous media flow. Here, we recount in detail from a methodological perspective, this model that can be assembled easily using materials commonly available in most microbiological laboratories. The entire procedure takes approximately two days to complete. Biofilms developed using this system are robust, and particularly suitable for studies requiring large amounts of biofilm cells for downstream analyses. This methodology simplifies biofilm formation under continuous replenishment of nutrients. Moreover, this technique mimics in vivo flow conditions, thereby making it physiologically more relevant than the currently dominant static models.
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Affiliation(s)
- Priya Uppuluri
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, USA
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590
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Martinez LR, Fries BC. Fungal Biofilms: Relevance in the Setting of Human Disease. CURRENT FUNGAL INFECTION REPORTS 2010; 4:266-275. [PMID: 21660222 DOI: 10.1007/s12281-010-0035-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The use of indwelling medical devices is rapidly growing and is often complicated by infections with biofilm-forming microbes that are resistant to antimicrobial agents and host defense mechanisms. Fungal biofilms have emerged as a clinical problem associated with these medical device infections, causing significant morbidity and mortality. This review discusses the recent advances in the understanding of fungal biofilms, including the role of fungal surface components in adherence, gene expression, and quorum sensing in biofilm formation. We propose novel strategies for the prevention or eradication of microbial colonization of medical prosthetic devices.
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Affiliation(s)
- Luis R Martinez
- Albert Einstein College of Medicine, 1300 Morris Park Avenue Bronx, Morris Park, NY 10461, USA
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591
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Nett JE, Marchillo K, Spiegel CA, Andes DR. Development and validation of an in vivo Candida albicans biofilm denture model. Infect Immun 2010; 78:3650-9. [PMID: 20605982 PMCID: PMC2937450 DOI: 10.1128/iai.00480-10] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 06/16/2010] [Accepted: 06/25/2010] [Indexed: 11/20/2022] Open
Abstract
The most common form of oral candidiasis, denture-associated stomatitis, involves biofilm growth on an oral prosthetic surface. Cells in this unique environment are equipped to withstand host defenses and survive antifungal therapy. Studies of the biofilm process on dentures have primarily been limited to in vitro models. We developed a rodent acrylic denture model and characterized the Candida albicans and mixed oral bacterial flora biofilm formation, architecture, and drug resistance in vivo, using time course quantitative culture experiments, confocal microscopy, scanning electron microscopy, and antifungal susceptibility assays. We also examined the utility of the model for measurement of C. albicans gene expression and tested the impact of a specific gene product (Bcr1p) on biofilm formation. Finally, we assessed the mucosal host response to the denture biofilm and found the mucosal histopathology to be consistent with that of acute human denture stomatitis, demonstrating fungal invasion and neutrophil infiltration. This current oral denture model mimics human denture stomatitis and should be useful for testing the impact of gene disruption on biofilm formation, studying the impact of anti-infectives, examining the biology of mixed Candida-oral bacterial flora biofilm infections, and characterizing the host immunologic response to this disease process.
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Affiliation(s)
- Jeniel E. Nett
- Departments of Medicine, Medical Microbiology and Immunology, Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin
| | - Karen Marchillo
- Departments of Medicine, Medical Microbiology and Immunology, Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin
| | - Carol A. Spiegel
- Departments of Medicine, Medical Microbiology and Immunology, Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin
| | - David R. Andes
- Departments of Medicine, Medical Microbiology and Immunology, Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin
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592
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Harriott MM, Lilly EA, Rodriguez TE, Fidel PL, Noverr MC. Candida albicans forms biofilms on the vaginal mucosa. MICROBIOLOGY-SGM 2010; 156:3635-3644. [PMID: 20705667 PMCID: PMC3068702 DOI: 10.1099/mic.0.039354-0] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Current understanding of resistance and susceptibility to vulvovaginal candidiasis challenges existing paradigms of host defence against fungal infection. While abiotic biofilm formation has a clearly established role during systemic Candida infections, it is not known whether C. albicans forms biofilms on the vaginal mucosa and the possible role of biofilms in disease. In vivo and ex vivo murine vaginitis models were employed to examine biofilm formation by scanning electron and confocal microscopy. C. albicans strains included 3153A (lab strain), DAY185 (parental control strain), and mutants defective in morphogenesis and/or biofilm formation in vitro (efg1/efg1 and bcr1/bcr1). Both 3153A and DAY815 formed biofilms on the vaginal mucosa in vivo and ex vivo as indicated by high fungal burden and microscopic analysis demonstrating typical biofilm architecture and presence of extracellular matrix (ECM) co-localized with the presence of fungi. In contrast, efg1/efg1 and bcr1/bcr1 mutant strains exhibited weak or no biofilm formation/ECM production in both models compared to wild-type strains and complemented mutants despite comparable colonization levels. These data show for the first time that C. albicans forms biofilms in vivo on vaginal epithelium, and that in vivo biotic biofilm formation requires regulators of biofilm formation (BCR1) and morphogenesis (EFG1).
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Affiliation(s)
- M. M. Harriott
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - E. A. Lilly
- Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - T. E. Rodriguez
- Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - P. L. Fidel
- Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - M. C. Noverr
- Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
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593
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Capric acid secreted by S. boulardii inhibits C. albicans filamentous growth, adhesion and biofilm formation. PLoS One 2010; 5:e12050. [PMID: 20706577 PMCID: PMC2919387 DOI: 10.1371/journal.pone.0012050] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 07/10/2010] [Indexed: 12/11/2022] Open
Abstract
Candidiasis are life-threatening systemic fungal diseases, especially of gastro intestinal track, skin and mucous membranes lining various body cavities like the nostrils, the mouth, the lips, the eyelids, the ears or the genital area. Due to increasing resistance of candidiasis to existing drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. One promising strategy is the use of the probiotic microorganisms, which when administered in adequate amounts confer a health benefit. Such a probiotic microorganism is yeast Saccharomyces boulardii, a close relative of baker yeast. Saccharomyces boulardii cells and their extract affect the virulence factors of the important human fungal pathogen C. albicans, its hyphae formation, adhesion and biofilm development. Extract prepared from S. boulardii culture filtrate was fractionated and GC-MS analysis showed that the active fraction contained, apart from 2-phenylethanol, caproic, caprylic and capric acid whose presence was confirmed by ESI-MS analysis. Biological activity was tested on C. albicans using extract and pure identified compounds. Our study demonstrated that this probiotic yeast secretes into the medium active compounds reducing candidal virulence factors. The chief compound inhibiting filamentous C. albicans growth comparably to S. boulardii extract was capric acid, which is thus responsible for inhibition of hyphae formation. It also reduced candidal adhesion and biofilm formation, though three times less than the extract, which thus contains other factors suppressing C. albicans adherence. The expression profile of selected genes associated with C. albicans virulence by real-time PCR showed a reduced expression of HWP1, INO1 and CSH1 genes in C. albicans cells treated with capric acid and S. boulardii extract. Hence capric acid secreted by S. boulardii is responsible for inhibition of C. albicans filamentation and partially also adhesion and biofilm formation.
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594
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Bujdáková H, Paulovičová E, Paulovičová L, Šimová Z. Participation of theCandida albicanssurface antigen in adhesion, the first phase of biofilm development. ACTA ACUST UNITED AC 2010; 59:485-92. [DOI: 10.1111/j.1574-695x.2010.00713.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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595
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Nett JE, Crawford K, Marchillo K, Andes DR. Role of Fks1p and matrix glucan in Candida albicans biofilm resistance to an echinocandin, pyrimidine, and polyene. Antimicrob Agents Chemother 2010; 54:3505-8. [PMID: 20516280 PMCID: PMC2916329 DOI: 10.1128/aac.00227-10] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 04/22/2010] [Accepted: 05/24/2010] [Indexed: 11/20/2022] Open
Abstract
Candida infections frequently involve drug-resistant biofilm growth on device surfaces. Glucan synthase gene FKS1 has been linked to triazole resistance in Candida biofilms. We tested the impact of FKS1 modulation on susceptibility to additional antifungal classes. Reduction of FKS1 expression rendered biofilms more susceptible to amphotericin B, anidulafungin, and flucytosine. Increased resistance to anidulafungin and amphotericin B was observed for biofilms overexpressing FKS1. These findings suggest that Candida biofilm glucan sequestration is a multidrug resistance mechanism.
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Affiliation(s)
- Jeniel E. Nett
- Departments of Medicine, Medical Microbiology and Immunology, Cellular and Molecular Biology, University of Wisconsin, Madison, Wisconsin
| | - Kyler Crawford
- Departments of Medicine, Medical Microbiology and Immunology, Cellular and Molecular Biology, University of Wisconsin, Madison, Wisconsin
| | - Karen Marchillo
- Departments of Medicine, Medical Microbiology and Immunology, Cellular and Molecular Biology, University of Wisconsin, Madison, Wisconsin
| | - David R. Andes
- Departments of Medicine, Medical Microbiology and Immunology, Cellular and Molecular Biology, University of Wisconsin, Madison, Wisconsin
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596
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Goossens K, Willaert R. Flocculation protein structure and cell–cell adhesion mechanism in Saccharomyces cerevisiae. Biotechnol Lett 2010; 32:1571-85. [DOI: 10.1007/s10529-010-0352-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 07/02/2010] [Indexed: 01/08/2023]
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597
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Sellam A, Hogues H, Askew C, Tebbji F, van Het Hoog M, Lavoie H, Kumamoto CA, Whiteway M, Nantel A. Experimental annotation of the human pathogen Candida albicans coding and noncoding transcribed regions using high-resolution tiling arrays. Genome Biol 2010; 11:R71. [PMID: 20618945 PMCID: PMC2926782 DOI: 10.1186/gb-2010-11-7-r71] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 06/07/2010] [Accepted: 07/09/2010] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Compared to other model organisms and despite the clinical relevance of the pathogenic yeast Candida albicans, no comprehensive analysis has been done to provide experimental support of its in silico-based genome annotation. RESULTS We have undertaken a genome-wide experimental annotation to accurately uncover the transcriptional landscape of the pathogenic yeast C. albicans using strand-specific high-density tiling arrays. RNAs were purified from cells growing under conditions relevant to C. albicans pathogenicity, including biofilm, lab-grown yeast and serum-induced hyphae, as well as cells isolated from the mouse caecum. This work provides a genome-wide experimental validation for a large number of predicted ORFs for which transcription had not been detected by other approaches. Additionally, we identified more than 2,000 novel transcriptional segments, including new ORFs and exons, non-coding RNAs (ncRNAs) as well as convincing cases of antisense gene transcription. We also characterized the 5' and 3' UTRs of expressed ORFs, and established that genes with long 5' UTRs are significantly enriched in regulatory functions controlling filamentous growth. Furthermore, we found that genomic regions adjacent to telomeres harbor a cluster of expressed ncRNAs. To validate and confirm new ncRNA candidates, we adapted an iterative strategy combining both genome-wide occupancy of the different subunits of RNA polymerases I, II and III and expression data. This comprehensive approach allowed the identification of different families of ncRNAs. CONCLUSIONS In summary, we provide a comprehensive expression atlas that covers relevant C. albicans pathogenic developmental stages in addition to the discovery of new ORF and non-coding genetic elements.
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Affiliation(s)
- Adnane Sellam
- Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount, Montréal, Québec, H4P 2R2, Canada.
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598
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Dutronc H, Dauchy FA, Cazanave C, Rougie C, Lafarie-Castet S, Couprie B, Fabre T, Dupon M. Candida prosthetic infections: case series and literature review. ACTA ACUST UNITED AC 2010; 42:890-5. [PMID: 20608769 DOI: 10.3109/00365548.2010.498023] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Candida prosthetic joint infections are considered to be rare. We retrospectively studied patients treated for Candida prosthetic infections between 1 January 1995 and 31 December 2007 in our infectious diseases department, a tertiary referral centre. We identified 7 patients, 4 with knee and 3 with hip prosthetic infections. The most frequent fungal agent was Candida albicans (4 cases), followed by Candida parapsilosis (2 cases) and Candida guillermondii (1 case). All the patients received antifungal treatment for a prolonged period. Five patients had their prosthesis removed and 3 had reimplantation, 1 patient was treated with debridement and prosthetic retention, and the last patient refused surgery. The mean follow-up time was 2.5 y. At the last evaluation, 3 patients were considered as cured, 3 patients presented a secondary bacterial infection leading to amputation for 2 of them, and 1 patient died from heart failure. During Candida prosthetic joint infections, the epidemiological characteristics and the location of the prosthesis are very similar to bacterial prosthetic infections. The benchmark antifungal therapies remain amphotericin B and/or fluconazole.
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Affiliation(s)
- Herve Dutronc
- Service de Maladies Infectieuses et Tropicales, Hôpital Pellegrin, Université Victor Segalen Bordeaux 2, CHU de Bordeaux, Bordeaux, France.
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599
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Silva S, Negri M, Henriques M, Oliveira R, Williams D, Azeredo J. Silicone colonization by non-Candida albicans Candida species in the presence of urine. J Med Microbiol 2010; 59:747-754. [DOI: 10.1099/jmm.0.017517-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Urinary tract infections (UTIs) are the most common nosocomial infections and 80 % are related to the use of urinary catheters. Furthermore, Candida species are responsible for around 15 % of UTIs and an increasing involvement of non-Candida albicans Candida (NCAC) species (e.g. Candida glabrata, Candida tropicalis and Candida parapsilosis) has been recognized. Given the fact that silicone is frequently used in the manufacture of urinary catheters, the aim of this work was to compare both the adhesion and biofilm formation on silicone of different urinary clinical isolates of NCAC species (i.e. C. glabrata, C. tropicalis and C. parapsilosis) in the presence of urine. Several clinical isolates of NCAC species recovered from patients with UTIs, together with reference strains of each species, were examined. Adhesion and biofilm formation were performed in artificial urine and the biofilm biomass was assessed by crystal violet staining. Hydrophobicity and surface charge of cells was determined by measuring contact angles and zeta potential, respectively. The number of viable cells in biofilms was determined by enumeration of c.f.u. after appropriate culture. The biofilm structure was also examined by confocal laser scanning microscopy (CLSM). The results showed that all isolates adhered to silicone in a species- and strain-dependent manner with C. parapsilosis showing the lowest and C. glabrata the highest levels of adhesion. However, these differences in adhesion abilities cannot be correlated with surface properties since all strains examined were hydrophilic and exhibited a similar zeta potential. Despite a higher number of cultivable cells being recovered after 72 h of incubation, stronger biofilm formation was not observed and CLSM showed an absence of extracellular polymeric material for all isolates examined. In summary, this work demonstrated that all tested NCAC species were able to adhere to and survive on silicone in the presence of urine. Furthermore, C. glabrata strains presented higher colonization abilities than C. tropicalis and C. parapsilosis strains, a fact that might explain the larger role of C. glabrata colonization and disseminated infections in hospitalized and catheterized patients.
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Affiliation(s)
- Sónia Silva
- Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Melyssa Negri
- Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Mariana Henriques
- Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Rosário Oliveira
- Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - David Williams
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, UK
| | - Joana Azeredo
- Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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600
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White JS, Walker GM. Influence of cell surface characteristics on adhesion of Saccharomyces cerevisiae to the biomaterial hydroxylapatite. Antonie van Leeuwenhoek 2010; 99:201-9. [DOI: 10.1007/s10482-010-9477-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 06/15/2010] [Indexed: 10/19/2022]
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