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Balla N, Jakab Á, Kovács F, Ragyák Á, Tóth Z, Balázsi D, Forgács L, Bozó A, Al Refai F, Borman AM, Majoros L, Kovács R. Total transcriptome analysis of Candida auris planktonic cells exposed to tyrosol. AMB Express 2023; 13:81. [PMID: 37532970 PMCID: PMC10397170 DOI: 10.1186/s13568-023-01586-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 07/20/2023] [Indexed: 08/04/2023] Open
Abstract
Tyrosol, a secondary metabolite of Candida species, regulates fungal morphogenesis, and its application may represent a novel innovative therapy against emerging multi-resistant fungal superbug such as Candida auris. In the current study, the effects of tyrosol on growth, redox homeostasis, intracellular microelement contents and activities of virulence-related enzymes released by C. auris were examined. To gain further information about the effect of tyrosol exposure, we revealed gene transcriptional changes using total transcriptome sequencing (RNA-Seq). At a concentration of 15 mM, tyrosol significantly decrease the growth of fungal cells within 2 h of its addition (5.6 × 107±1.2 × 107 and 2.5 × 107±0.6 × 107 colony forming unit/mL for control and tyrosol-treated cells, respectively). Furthermore, it enhanced the release of reactive oxygen species as confirmed by a dichlorofluorescein (DCF) assay (7.3 ± 1.8 [nmol DCF (OD640)-1] versus 16.8 ± 3.9 [nmol DCF (OD640)-1]), which was coincided with elevated superoxide dismutase, catalase and glutathione peroxidase activities. Tyrosol exerted in a 37%, 25%, 34% and 55% decrease in intracellular manganese, iron, zinc and copper contents, respectively, compared to control cells. The tyrosol treatment led to a 142 and 108 differentially transcripted genes with at least a 1.5-fold increase or decrease in transcription, respectively. Genes related to iron and fatty acid metabolism as well as nucleic acid synthesis were down-regulated, whereas those related to the antioxidative defence, adhesion and oxoacid metabolic processes were up-regulated. This study shows that tyrosol significantly influences growth, intracellular physiological processes and gene transcription in C. auris, which could highly support the development of novel treatment approaches against this important pathogen.
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Affiliation(s)
- Noémi Balla
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, 4032, Hungary
| | - Ágnes Jakab
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Fruzsina Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, 4032, Hungary
| | - Ágota Ragyák
- Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, Hungary
| | - Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Dávid Balázsi
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, 4032, Hungary
| | - Lajos Forgács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, 4032, Hungary
| | - Aliz Bozó
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Farah Al Refai
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Andrew M Borman
- UK National Mycology Reference Laboratory, Public Health England, Science Quarter, Southmead Hospital, Bristol, BS10 5NB, UK
- Medical Research Council Centre for Medical Mycology (MRCCMM), University of Exeter, Exeter, EX4 4QD, UK
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary.
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Smoak RA, Snyder LF, Fassler JS, He BZ. Parallel expansion and divergence of an adhesin family in pathogenic yeasts. Genetics 2023; 223:iyad024. [PMID: 36794645 PMCID: PMC10319987 DOI: 10.1093/genetics/iyad024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
Opportunistic yeast pathogens arose multiple times in the Saccharomycetes class, including the recently emerged, multidrug-resistant (MDR) Candida auris. We show that homologs of a known yeast adhesin family in Candida albicans, the Hyr/Iff-like (Hil) family, are enriched in distinct clades of Candida species as a result of multiple, independent expansions. Following gene duplication, the tandem repeat-rich region in these proteins diverged extremely rapidly and generated large variations in length and β-aggregation potential, both of which are known to directly affect adhesion. The conserved N-terminal effector domain was predicted to adopt a β-helical fold followed by an α-crystallin domain, making it structurally similar to a group of unrelated bacterial adhesins. Evolutionary analyses of the effector domain in C. auris revealed relaxed selective constraint combined with signatures of positive selection, suggesting functional diversification after gene duplication. Lastly, we found the Hil family genes to be enriched at chromosomal ends, which likely contributed to their expansion via ectopic recombination and break-induced replication. Combined, these results suggest that the expansion and diversification of adhesin families generate variation in adhesion and virulence within and between species and are a key step toward the emergence of fungal pathogens.
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Affiliation(s)
- Rachel A Smoak
- Civil and Environmental Engineering, The University of Iowa, Iowa City, IA 52242, USA
| | - Lindsey F Snyder
- Interdisciplinary Graduate Program in Genetics, The University of Iowa, Iowa City, IA 52242, USA
| | - Jan S Fassler
- Interdisciplinary Graduate Program in Genetics, The University of Iowa, Iowa City, IA 52242, USA
- Department of Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Bin Z He
- Interdisciplinary Graduate Program in Genetics, The University of Iowa, Iowa City, IA 52242, USA
- Department of Biology, The University of Iowa, Iowa City, IA 52242, USA
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Transcriptomics and Phenotyping Define Genetic Signatures Associated with Echinocandin Resistance in Candida auris. mBio 2022; 13:e0079922. [PMID: 35968956 PMCID: PMC9426441 DOI: 10.1128/mbio.00799-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida auris emerged as a human fungal pathogen only during the past decade. Remarkably, C. auris displays high degrees of genomic diversity and phenotypic plasticity, with four major clades causing hospital outbreaks with high mortality and morbidity rates. C. auris can show clinical resistance to all classes of antifungal drugs, including echinocandins that are usually recommended as first-line therapies for invasive candidiasis. Here, we exploit transcriptomics coupled with phenotypic profiling to characterize a set of clinical C. auris isolates displaying pronounced echinocandin resistance (ECN-R). A hot spot mutation in the echinocandin FKS1 target gene is present in all resistant isolates. Moreover, ECN-R strains share a core signature set of 362 genes differentially expressed in ECN-R isolates. Among others, mitochondrial gene expression and genes affecting cell wall function appear to be the most prominent, with the latter correlating well with enhanced adhesive traits, increased cell wall mannan content, and altered sensitivity to cell wall stress of ECN-R isolates. Moreover, ECN-R phenotypic signatures were also linked to pathogen recognition and interaction with immune cells. Hence, transcriptomics paired with phenotyping is a suitable tool to predict resistance and fitness traits as well as treatment outcomes in pathogen populations with complex phenotypic diversity. IMPORTANCE The surge in antimicrobial drug resistance in some bacterial and fungal pathogens constitutes a significant challenge to health care facilities. The emerging human fungal pathogen Candida auris has been particularly concerning, as isolates can display pan-antifungal resistance traits against all drugs, including echinocandins. However, the mechanisms underlying this phenotypic diversity remain poorly understood. We identify transcriptomic signatures in C. auris isolates resistant to otherwise fungicidal echinocandins. We identify a set of differentially expressed genes shared by resistant strains compared to unrelated susceptible isolates. Moreover, phenotyping demonstrates that resistant strains show distinct behaviors, with implications for host-pathogen interactions. Hence, this work provides a solid basis to identify the mechanistic links between antifungal multidrug resistance and fitness costs that affect the interaction of C. auris with host immune defenses.
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A novel class of Candida glabrata cell wall proteins with β-helix fold mediates adhesion in clinical isolates. PLoS Pathog 2021; 17:e1009980. [PMID: 34962966 PMCID: PMC8746771 DOI: 10.1371/journal.ppat.1009980] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 01/10/2022] [Accepted: 11/30/2021] [Indexed: 11/19/2022] Open
Abstract
Candida glabrata is an opportunistic pathogenic yeast frequently causing infections in humans. Though it lacks typical virulence factors such as hyphal development, C. glabrata contains a remarkably large and diverse set of putative wall adhesins that is crucial for its success as pathogen. Here, we present an analysis of putative adhesins from the homology clusters V and VI. First, sequence similarity network analysis revealed relationships between cluster V and VI adhesins and S. cerevisiae haze protective factors (Hpf). Crystal structures of A-regions from cluster VI adhesins Awp1 and Awp3b reveal a parallel right-handed β-helix domain that is linked to a C-terminal β-sandwich. Structure solution of the A-region of Awp3b via single wavelength anomalous diffraction phasing revealed the largest known lanthanide cluster with 21 Gd3+ ions. Awp1-A and Awp3b-A show structural similarity to pectate lyases but binding to neither carbohydrates nor Ca2+ was observed. Phenotypic analysis of awp1Δ, awp3Δ, and awp1,3Δ double mutants did also not confirm their role as adhesins. In contrast, deletion mutants of the cluster V adhesin Awp2 in the hyperadhesive clinical isolate PEU382 demonstrated its importance for adhesion to polystyrene or glass, biofilm formation, cell aggregation and other cell surface-related phenotypes. Together with cluster III and VII adhesins our study shows that C. glabrata CBS138 can rely on a set of 42 Awp1-related adhesins with β-helix/α-crystallin domain architecture for modifying the surface characteristics of its cell wall. Adhesion to host cells and abiotic, often hydrophobic surfaces, e.g. that of medical equipment like catheters, is an indispensable virulence factor for many pathogenic fungi. Among the latter, the yeast Candida glabrata excels by encoding in its genome large sets of surface-exposed cell wall proteins. Here, we show that in the clinical isolate PEU382 of C. glabrata, hyper-adhesiveness to plastics and the tendency to biofilm formation is conferred by a single adhesin, Awp2. An integrative bioinformatic and structural analysis of this and the related Awp1 and Awp3 adhesins unifies four, so far separately assigned Awp clusters—III, V, VI and VII–into one consisting of 42 Awp1-related adhesins. These adhesins commonly present an N-terminal module consisting of a right-handed β-helix and an α-crystallin domain on the yeast surface and use a calcium-independent mode for adhesion. Their sheer number contrasts to the 20 members of the well characterized Epa and 7 members of the Pwp family of surface proteins. Given these findings we suggest that C. glabrata utilizes just two structurally distinct motifs for colonizing different host niches by adhesion: the β-helix/α-crystallin module of Awp1-related adhesins and the C-type lectin PA14-domain for Epa and Pwp proteins.
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Rosiana S, Zhang L, Kim GH, Revtovich AV, Uthayakumar D, Sukumaran A, Geddes-McAlister J, Kirienko NV, Shapiro RS. Comprehensive genetic analysis of adhesin proteins and their role in virulence of Candida albicans. Genetics 2021; 217:iyab003. [PMID: 33724419 PMCID: PMC8045720 DOI: 10.1093/genetics/iyab003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/31/2020] [Indexed: 12/14/2022] Open
Abstract
Candida albicans is a microbial fungus that exists as a commensal member of the human microbiome and an opportunistic pathogen. Cell surface-associated adhesin proteins play a crucial role in C. albicans' ability to undergo cellular morphogenesis, develop robust biofilms, colonize, and cause infection in a host. However, a comprehensive analysis of the role and relationships between these adhesins has not been explored. We previously established a CRISPR-based platform for efficient generation of single- and double-gene deletions in C. albicans, which was used to construct a library of 144 mutants, comprising 12 unique adhesin genes deleted singly, and every possible combination of double deletions. Here, we exploit this adhesin mutant library to explore the role of adhesin proteins in C. albicans virulence. We perform a comprehensive, high-throughput screen of this library, using Caenorhabditis elegans as a simplified model host system, which identified mutants critical for virulence and significant genetic interactions. We perform follow-up analysis to assess the ability of high- and low-virulence strains to undergo cellular morphogenesis and form biofilms in vitro, as well as to colonize the C. elegans host. We further perform genetic interaction analysis to identify novel significant negative genetic interactions between adhesin mutants, whereby combinatorial perturbation of these genes significantly impairs virulence, more than expected based on virulence of the single mutant constituent strains. Together, this study yields important new insight into the role of adhesins, singly and in combinations, in mediating diverse facets of virulence of this critical fungal pathogen.
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Affiliation(s)
- Sierra Rosiana
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | - Liyang Zhang
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Grace H Kim
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | | | - Deeva Uthayakumar
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | - Arjun Sukumaran
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | | | | | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
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Fregonezi NF, Oliveira LT, Singulani JDL, Marcos CM, Dos Santos CT, Taylor ML, Mendes-Giannini MJS, de Oliveira HC, Fusco-Almeida AM. Heat Shock Protein 60, Insights to Its Importance in Histoplasma capsulatum: From Biofilm Formation to Host-Interaction. Front Cell Infect Microbiol 2021; 10:591950. [PMID: 33553002 PMCID: PMC7862341 DOI: 10.3389/fcimb.2020.591950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/04/2020] [Indexed: 12/04/2022] Open
Abstract
Heat shock proteins (Hsps) are among the most widely distributed and evolutionary conserved proteins, acting as essential regulators of diverse constitutive metabolic processes. The Hsp60 of the dimorphic fungal Histoplasma capsulatum is the major surface adhesin to mammalian macrophages and studies of antibody-mediated protection against H. capsulatum have provided insight into the complexity involving Hsp60. However, nothing is known about the role of Hsp60 regarding biofilms, a mechanism of virulence exhibited by H. capsulatum. Considering this, the present study aimed to investigate the influence of the Hsp60 on biofilm features of H. capsulatum. Also, the non-conventional model Galleria mellonella was used to verify the effect of this protein during in vivo interaction. The use of invertebrate models such as G. mellonella is highly proposed for the evaluation of pathogenesis, immune response, virulence mechanisms, and antimicrobial compounds. For that purpose, we used a monoclonal antibody (7B6) against Hsp60 and characterized the biofilm of two H. capsulatum strains by metabolic activity, biomass content, and images from scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). We also evaluated the survival rate of G. mellonella infected with both strains under blockage of Hsp60. The results showed that mAb 7B6 was effective to reduce the metabolic activity and biomass of both H. capsulatum strains. Furthermore, the biofilms of cells treated with the antibody were thinner as well as presented a lower amount of cells and extracellular polymeric matrix compared to its non-treated controls. The blockage of Hsp60 before fungal infection of G. mellonella larvae also resulted in a significant increase of the larvae survival compared to controls. Our results highlight for the first time the importance of the Hsp60 protein to the establishment of the H. capsulatum biofilms and the G. mellonella larvae infection. Interestingly, the results with Hsp60 mAb 7B6 in this invertebrate model suggest a pattern of fungus-host interaction different from those previously found in a murine model, which can be due to the different features between insect and mammalian immune cells such as the absence of Fc receptors in hemocytes. However further studies are needed to support this hypothesis
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Affiliation(s)
- Nathália Ferreira Fregonezi
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
| | - Lariane Teodoro Oliveira
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
| | - Junya de Lacorte Singulani
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
| | - Caroline Maria Marcos
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
| | - Claudia Tavares Dos Santos
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
| | - Maria Lucia Taylor
- Unidad de Micología, Departamento de Microbiología y Parasitología, Facultad de Medicina, UNAM-Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | - Haroldo Cesar de Oliveira
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
| | - Ana Marisa Fusco-Almeida
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University-UNESP, Araraquara, Brazil
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Comparative genomics reveals the origin of fungal hyphae and multicellularity. Nat Commun 2019; 10:4080. [PMID: 31501435 PMCID: PMC6733946 DOI: 10.1038/s41467-019-12085-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 08/20/2019] [Indexed: 02/01/2023] Open
Abstract
Hyphae represent a hallmark structure of multicellular fungi. The evolutionary origins of hyphae and of the underlying genes are, however, hardly known. By systematically analyzing 72 complete genomes, we here show that hyphae evolved early in fungal evolution probably via diverse genetic changes, including co-option and exaptation of ancient eukaryotic (e.g. phagocytosis-related) genes, the origin of new gene families, gene duplications and alterations of gene structure, among others. Contrary to most multicellular lineages, the origin of filamentous fungi did not correlate with expansions of kinases, receptors or adhesive proteins. Co-option was probably the dominant mechanism for recruiting genes for hypha morphogenesis, while gene duplication was apparently less prevalent, except in transcriptional regulators and cell wall - related genes. We identified 414 novel gene families that show correlated evolution with hyphae and that may have contributed to its evolution. Our results suggest that hyphae represent a unique multicellular organization that evolved by limited fungal-specific innovations and gene duplication but pervasive co-option and modification of ancient eukaryotic functions.
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LIN MY, YUAN ZL, HU DD, HU GH, ZHANG RL, ZHONG H, YAN L, JIANG YY, SU J, WANG Y. Effect of loureirin A against Candida albicans biofilms. Chin J Nat Med 2019; 17:616-623. [DOI: 10.1016/s1875-5364(19)30064-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Indexed: 12/27/2022]
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de Jong AW, Hagen F. Attack, Defend and Persist: How the Fungal Pathogen Candida auris was Able to Emerge Globally in Healthcare Environments. Mycopathologia 2019; 184:353-365. [PMID: 31209693 DOI: 10.1007/s11046-019-00351-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 05/28/2019] [Indexed: 12/25/2022]
Abstract
Within a decade after its first description, the multidrug-resistant yeast Candida auris has emerged globally as a nosocomial pathogen causing difficult to control outbreaks. This, together with the alarmingly high mortality rate of up to 66% associated with C. auris candidemia, calls for a better understanding of its virulence traits and routes of transmission. Unlike other clinically relevant Candida species, C. auris seems to have the unique ability to be easily transmitted between patients. Although initially thought to express fewer virulence traits than Candida albicans, recent genomic insights suggest C. auris to possess these traits to a much more similar extent. This review highlights the virulence traits C. auris expresses to attack the host, defend itself against antimicrobial agents and to persist within the healthcare environment.
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Affiliation(s)
- Auke W de Jong
- Department of Medical Mycology, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Ferry Hagen
- Department of Medical Mycology, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
- Laboratory of Medical Mycology, Jining No. 1 People's Hospital, Jining, Shandong, People's Republic of China.
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Kean R, Delaney C, Sherry L, Borman A, Johnson EM, Richardson MD, Rautemaa-Richardson R, Williams C, Ramage G. Transcriptome Assembly and Profiling of Candida auris Reveals Novel Insights into Biofilm-Mediated Resistance. mSphere 2018; 3:e00334-18. [PMID: 29997121 PMCID: PMC6041501 DOI: 10.1128/msphere.00334-18] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 06/21/2018] [Indexed: 12/13/2022] Open
Abstract
Candida auris has emerged as a significant global nosocomial pathogen. This is primarily due to its antifungal resistance profile but also its capacity to form adherent biofilm communities on a range of clinically important substrates. While we have a comprehensive understanding of how other Candida species resist and respond to antifungal challenge within the sessile phenotype, our current understanding of C. auris biofilm-mediated resistance is lacking. In this study, we are the first to perform transcriptomic analysis of temporally developing C. auris biofilms, which were shown to exhibit phase- and antifungal class-dependent resistance profiles. A de novo transcriptome assembly was performed, where sequenced sample reads were assembled into an ~11.5-Mb transcriptome consisting of 5,848 genes. Differential expression (DE) analysis demonstrated that 791 and 464 genes were upregulated in biofilm formation and planktonic cells, respectively, with a minimum 2-fold change. Adhesin-related glycosylphosphatidylinositol (GPI)-anchored cell wall genes were upregulated at all time points of biofilm formation. As the biofilm developed into intermediate and mature stages, a number of genes encoding efflux pumps were upregulated, including ATP-binding cassette (ABC) and major facilitator superfamily (MFS) transporters. When we assessed efflux pump activity biochemically, biofilm efflux was greater than that of planktonic cells at 12 and 24 h. When these were inhibited, fluconazole sensitivity was enhanced 4- to 16-fold. This study demonstrates the importance of efflux-mediated resistance within complex C. auris communities and may explain the resistance of C. auris to a range of antimicrobial agents within the hospital environment.IMPORTANCE Fungal infections represent an important cause of human morbidity and mortality, particularly if the fungi adhere to and grow on both biological and inanimate surfaces as communities of cells (biofilms). Recently, a previously unrecognized yeast, Candida auris, has emerged globally that has led to widespread concern due to the difficulty in treating it with existing antifungal agents. Alarmingly, it is also able to grow as a biofilm that is highly resistant to antifungal agents, yet we are unclear about how it does this. Here, we used a molecular approach to investigate the genes that are important in causing the cells to be resistant within the biofilm. The work provides significant insights into the importance of efflux pumps, which actively pump out toxic antifungal drugs and therefore enhance fungal survival within a variety of harsh environments.
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Affiliation(s)
- Ryan Kean
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Institute of Healthcare, Policy and Practise, University of the West of Scotland, Paisley, United Kingdom
| | - Christopher Delaney
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Leighann Sherry
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew Borman
- National Mycology Reference Laboratory, Public Health England South-West, Bristol, United Kingdom
| | - Elizabeth M Johnson
- National Mycology Reference Laboratory, Public Health England South-West, Bristol, United Kingdom
| | - Malcolm D Richardson
- Mycology Reference Centre Manchester, University Hospital of South Manchester & University of Manchester, Manchester Academic Health Sciences Centre, Faculty of Biology, Medicine and Health, Division of Infection, Immunity and Respiratory Medicine, Manchester, United Kingdom
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester, University Hospital of South Manchester & University of Manchester, Manchester Academic Health Sciences Centre, Faculty of Biology, Medicine and Health, Division of Infection, Immunity and Respiratory Medicine, Manchester, United Kingdom
| | - Craig Williams
- Institute of Healthcare, Policy and Practise, University of the West of Scotland, Paisley, United Kingdom
- ESCMID Study Group for Biofilms (ESGB)‡
| | - Gordon Ramage
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- ESCMID Study Group for Biofilms (ESGB)‡
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11
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An overview of lectin–glycan interactions: a key event in initiating fungal infection and pathogenesis. Arch Microbiol 2018; 200:371-382. [DOI: 10.1007/s00203-018-1487-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/01/2017] [Accepted: 01/30/2018] [Indexed: 01/16/2023]
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12
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Qin Y, Zhang L, Xu Z, Zhang J, Jiang YY, Cao Y, Yan T. Innate immune cell response upon Candida albicans infection. Virulence 2016; 7:512-26. [PMID: 27078171 DOI: 10.1080/21505594.2016.1138201] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Candida albicans is a polymorphic fungus which is the predominant cause of superficial and deep tissue fungal infections. This microorganism has developed efficient strategies to invade the host and evade host defense systems. However, the host immune system will be prepared for defense against the microbe by recognition of receptors, activation of signal transduction pathways and cooperation of immune cells. As a consequence, C. albicans could either be eliminated by immune cells rapidly or disseminate hematogenously, leading to life-threatening systemic infections. The interplay between Candida albicans and the host is complex, requiring recognition of the invaded pathogens, activation of intricate pathways and collaboration of various immune cells. In this review, we will focus on the effects of innate immunity that emphasize the first line protection of host defense against invaded C. albicans including the basis of receptor-mediated recognition and the mechanisms of cell-mediated immunity.
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Affiliation(s)
- Yulin Qin
- a Research and Develop Center of New Drug, School of Pharmacy, Second Military Medical University , Shanghai , China
| | - Lulu Zhang
- a Research and Develop Center of New Drug, School of Pharmacy, Second Military Medical University , Shanghai , China
| | - Zheng Xu
- a Research and Develop Center of New Drug, School of Pharmacy, Second Military Medical University , Shanghai , China
| | - Jinyu Zhang
- a Research and Develop Center of New Drug, School of Pharmacy, Second Military Medical University , Shanghai , China
| | - Yuan-Ying Jiang
- a Research and Develop Center of New Drug, School of Pharmacy, Second Military Medical University , Shanghai , China
| | - Yongbing Cao
- a Research and Develop Center of New Drug, School of Pharmacy, Second Military Medical University , Shanghai , China
| | - Tianhua Yan
- b Department of Pharmacology , School of Pharmacy, China Pharmaceutical University , Nanjing , China
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All about that fat: Lipid modification of proteins in Cryptococcus neoformans. J Microbiol 2016; 54:212-22. [PMID: 26920881 DOI: 10.1007/s12275-016-5626-6] [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] [Received: 12/21/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022]
Abstract
Lipid modification of proteins is a widespread, essential process whereby fatty acids, cholesterol, isoprenoids, phospholipids, or glycosylphospholipids are attached to polypeptides. These hydrophobic groups may affect protein structure, function, localization, and/or stability; as a consequence such modifications play critical regulatory roles in cellular systems. Recent advances in chemical biology and proteomics have allowed the profiling of modified proteins, enabling dissection of the functional consequences of lipid addition. The enzymes that mediate lipid modification are specific for both the lipid and protein substrates, and are conserved from fungi to humans. In this article we review these enzymes, their substrates, and the processes involved in eukaryotic lipid modification of proteins. We further focus on its occurrence in the fungal pathogen Cryptococcus neoformans, highlighting unique features that are both relevant for the biology of the organism and potentially important in the search for new therapies.
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Abstract
Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity.
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Affiliation(s)
- Siobhán A Turner
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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Semlali A, Killer K, Alanazi H, Chmielewski W, Rouabhia M. Cigarette smoke condensate increases C. albicans adhesion, growth, biofilm formation, and EAP1, HWP1 and SAP2 gene expression. BMC Microbiol 2014; 14:61. [PMID: 24618025 PMCID: PMC3995653 DOI: 10.1186/1471-2180-14-61] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/07/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Smokers are more prone to oral infections than are non-smokers. Cigarette smoke reaches the host cells but also microorganisms present in the oral cavity. The contact between cigarette smoke and oral bacteria promotes such oral diseases as periodontitis. Cigarette smoke can also modulate C. albicans activities that promote oral candidiasis. The goal of this study was to investigate the effect of cigarette smoke condensate on C. albicans adhesion, growth, and biofilm formation as well as the activation of EAP1, HWP1 and secreted aspartic protease 2. RESULTS Cigarette smoke condensate (CSC) increased C. albicans adhesion and growth, as well as biofilm formation. These features may be supported by the activation of certain important genes. Using quantitative RT-PCR, we demonstrated that CSC-exposed C. albicans expressed high levels of EAP1, HWP1 and SAP2 mRNA and that this gene expression increased with increasing concentrations of CSC. CONCLUSION CSC induction of C. albicans adhesion, growth, and biofilm formation may explain the increased persistence of this pathogen in smokers. These findings may also be relevant to other biofilm-induced oral diseases.
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Affiliation(s)
| | | | | | | | - Mahmoud Rouabhia
- Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, 2420 rue de la Terrasse, Québec G1V 0A6, Canada.
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Abstract
Understanding the pathogenesis of an infectious disease is critical for developing new methods to prevent infection and diagnose or cure disease. Adherence of microorganisms to host tissue is a prerequisite for tissue invasion and infection. Fungal cell wall adhesins involved in adherence to host tissue or abiotic medical devices are critical for colonization leading to invasion and damage of host tissue. Here, with a main focus on pathogenic Candida species, we summarize recent progress made in the field of adhesins in human fungal pathogens and underscore the importance of these proteins in establishment of fungal diseases.
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Rouabhia M, Semlali A, Audoy J, Chmielewski W. Antagonistic effect of Candida albicans and IFNγ on E-cadherin expression and production by human primary gingival epithelial cells. Cell Immunol 2012; 280:61-7. [PMID: 23261830 DOI: 10.1016/j.cellimm.2012.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 10/18/2012] [Accepted: 11/12/2012] [Indexed: 10/27/2022]
Abstract
Caused mainly by Candida albicans, oropharyngeal candidiasis is the most common oral complication associated with HIV disease worldwide. Host defenses against C. albicans essentially fall into two categories: specific immune mechanisms and local oral mucosal epithelial cell defenses. Since oral mucosa is the first line of defense in the form of a physical barrier against C. albicans invasion, and since epithelial cells are involved in anti-Candida innate immunity through different cytokines, we wanted to determine whether C. albicans alters E-cadherin expression and production, and whether interferon-γ (INFγ), a TH1 cytokine, is involved in the anti-Candida defense. Using primary human gingival epithelial cells, we demonstrated that C. albicans significantly decreased E-cadherin mRNA expression and protein production. This effect was basically obtained at later infective periods (24 and 48h). Interestingly, when IFNγ was added to C. albicans infected epithelial cell cultures, it prevented the side effect of C. albicans on E-cadherin mRNA expression and protein production and deposition. All together, these results suggested concomitant interactions between oral epithelial cells and IFNγ against C. albicans infection.
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Affiliation(s)
- Mahmoud Rouabhia
- Groupe de Recherche en Écologie Buccale, Université Laval, Québec, Québec, Canada.
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Kempf M, Eveillard M, Deshayes C, Ghamrawi S, Lefrançois C, Georgeault S, Bastiat G, Seifert H, Joly-Guillou ML. Cell surface properties of two differently virulent strains of Acinetobacter baumannii isolated from a patient. Can J Microbiol 2012; 58:311-7. [PMID: 22356530 DOI: 10.1139/w11-131] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The aim of this study was to unravel, by focusing on cell surface properties, the underlying virulence factors contributing to the difference in the pathogenicity observed in two Acinetobacter baumannii strains isolated from the same patient. The two strains were phenotypically different: (i) a mucoid strain (AB-M), highly virulent in a mouse model of pneumonia, and (ii) a nonmucoid strain (AB-NM), moderately virulent in the same model. The study of the cell surface properties included the microbial adhesion to solvents method, the measurement of the electrophoretic mobility of bacteria, the analysis of biofilm formation by calcofluor white staining, the adherence to silicone catheters, and scanning electron microscopy. The AB-NM strain was more hydrophobic, more adherent to silicone catheters, and produced more biofilm than the AB-M strain. Scanning electron microscopy showed bacterial cells with a rough surface and the formation of large cell clusters for AB-NM whereas the AB-M strain had a smooth surface and formed only a few cell clusters. Contrary to the results of most previous studies, cell surface properties were not correlated to the virulence described in our experimental model, indicating that mechanisms other than adherence may be involved in the expression of A. baumannii virulence.
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Affiliation(s)
- Marie Kempf
- Groupe d'étude des interactions hôte-pathogène, UPRES EA 3142, Université d'Angers, France
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Unexpected role for a serine/threonine-rich domain in the Candida albicans Iff protein family. EUKARYOTIC CELL 2011; 10:1317-30. [PMID: 21841123 DOI: 10.1128/ec.05044-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins are an important class of cell wall proteins in Candida albicans because of their localization and their function, even if more than half of them have no characterized homolog in the databases. In this study, we focused on the IFF protein family, investigating their exposure on the cell surface and the sequences that determine their subcellular localization. Protein localization and surface exposure were monitored by the addition of a V5 tag on all members of the family. The data obtained using the complete proteins showed for Iff3 (or -9), Iff5, Iff6, and Iff8 a covalent linkage to the β-1,6-glucan network but, remarkably, showed that Iff2/Hyr3 was linked through disulfide bridges or NaOH-labile bonds. However, since some proteins of the Iff family were undetectable, we designed chimeric constructions using the last 60 amino acids of these proteins to test the localization signal. These constructions showed a β-1,6-glucan linkage for Iff1/Rbr3, Iff2/Hyr3, Iff4 and Iff7/Hyr4 C-terminal-Iff5 fusion proteins, and a membrane localization for the Iff10/Flo9 C terminus-Iff5 fusion protein. Immunofluorescence analyses coupled to these cell fraction data confirmed the importance of the length of the central serine/threonine-rich region for cell surface exposure. Further analysis of the Iff2/Hyr3 linkage to the cell surface showed for the first time that a serine/threonine central region of a GPI-anchored protein may be responsible for the disulfide and the NaOH bonds to the glucan and glycoproteins network and may also override the signal of the proximal ω site region.
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Chaudhuri R, Ansari FA, Raghunandanan MV, Ramachandran S. FungalRV: adhesin prediction and immunoinformatics portal for human fungal pathogens. BMC Genomics 2011; 12:192. [PMID: 21496229 PMCID: PMC3224177 DOI: 10.1186/1471-2164-12-192] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 04/15/2011] [Indexed: 01/11/2023] Open
Abstract
Background The availability of sequence data of human pathogenic fungi generates opportunities to develop Bioinformatics tools and resources for vaccine development towards benefitting at-risk patients. Description We have developed a fungal adhesin predictor and an immunoinformatics database with predicted adhesins. Based on literature search and domain analysis, we prepared a positive dataset comprising adhesin protein sequences from human fungal pathogens Candida albicans, Candida glabrata, Aspergillus fumigatus, Coccidioides immitis, Coccidioides posadasii, Histoplasma capsulatum, Blastomyces dermatitidis, Pneumocystis carinii, Pneumocystis jirovecii and Paracoccidioides brasiliensis. The negative dataset consisted of proteins with high probability to function intracellularly. We have used 3945 compositional properties including frequencies of mono, doublet, triplet, and multiplets of amino acids and hydrophobic properties as input features of protein sequences to Support Vector Machine. Best classifiers were identified through an exhaustive search of 588 parameters and meeting the criteria of best Mathews Correlation Coefficient and lowest coefficient of variation among the 3 fold cross validation datasets. The "FungalRV adhesin predictor" was built on three models whose average Mathews Correlation Coefficient was in the range 0.89-0.90 and its coefficient of variation across three fold cross validation datasets in the range 1.2% - 2.74% at threshold score of 0. We obtained an overall MCC value of 0.8702 considering all 8 pathogens, namely, C. albicans, C. glabrata, A. fumigatus, B. dermatitidis, C. immitis, C. posadasii, H. capsulatum and P. brasiliensis thus showing high sensitivity and specificity at a threshold of 0.511. In case of P. brasiliensis the algorithm achieved a sensitivity of 66.67%. A total of 307 fungal adhesins and adhesin like proteins were predicted from the entire proteomes of eight human pathogenic fungal species. The immunoinformatics analysis data on these proteins were organized for easy user interface analysis. A Web interface was developed for analysis by users. The predicted adhesin sequences were processed through 18 immunoinformatics algorithms and these data have been organized into MySQL backend. A user friendly interface has been developed for experimental researchers for retrieving information from the database. Conclusion FungalRV webserver facilitating the discovery process for novel human pathogenic fungal adhesin vaccine has been developed.
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Affiliation(s)
- Rupanjali Chaudhuri
- G.N Ramachandran Knowledge Centre for Genome Informatics, Institute of Genomics and Integrative Biology, Delhi 110007, India
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Current awareness on yeast. Yeast 2009. [DOI: 10.1002/yea.1627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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