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The Two-Component Response Regulator Ssk1 and the Mitogen-Activated Protein Kinase Hog1 Control Antifungal Drug Resistance and Cell Wall Architecture of Candida auris. mSphere 2020; 5:5/5/e00973-20. [PMID: 33055262 PMCID: PMC7565899 DOI: 10.1128/msphere.00973-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Candida auris is an emerging multidrug-resistant (MDR) fungal pathogen that presents a serious global threat to human health. The Centers for Disease Control and Prevention (CDC) have classified C. auris as an urgent threat to public health for the next decade due to its major clinical and economic impact and the lack of effective antifungal drugs and because of future projections concerning new C. auris infections. Importantly, the Global Antimicrobial Resistance Surveillance System (GLASS) has highlighted the need for more robust and efficacious global surveillance schemes enabling the identification and monitoring of antifungal resistance in Candida infections. Despite the clinical relevance of C. auris infections, our overall understanding of its pathophysiology and virulence, its response to human immune surveillance, and the molecular basis of multiple antifungal resistance remains in its infancy. Here, we show a marked phenotypic plasticity of C. auris clinical isolates. Further, we demonstrate critical roles of stress response mechanisms in regulating multidrug resistance and show that cell wall architecture and composition are key elements that determine antifungal drug susceptibilities. Our data promise new therapeutic options to treat drug-refractory C. auris infections. Candida auris is an emerging multidrug-resistant human fungal pathogen refractory to treatment by several classes of antifungal drugs. Unlike other Candida species, C. auris can adhere to human skin for prolonged periods of time, allowing for efficient skin-to-skin transmission in the hospital environments. However, molecular mechanisms underlying pronounced multidrug resistance and adhesion traits are poorly understood. Two-component signal transduction and mitogen-activated protein (MAP) kinase signaling are important regulators of adherence, antifungal drug resistance, and virulence. Here, we report that genetic removal of SSK1 encoding a response regulator and the mitogen-associated protein kinase HOG1 restores the susceptibility to both amphotericin B (AMB) and caspofungin (CAS) in C. auris clinical strains. The loss of SSK1 and HOG1 alters membrane lipid permeability, cell wall mannan content, and hyperresistance to cell wall-perturbing agents. Interestingly, our data reveal variable functions of SSK1 and HOG1 in different C. auris clinical isolates, suggesting a pronounced genetic plasticity affecting cell wall function, stress adaptation, and multidrug resistance. Taken together, our data suggest that targeting two-component signal transduction systems could be suitable for restoring C. auris susceptibility to antifungal drugs. IMPORTANCECandida auris is an emerging multidrug-resistant (MDR) fungal pathogen that presents a serious global threat to human health. The Centers for Disease Control and Prevention (CDC) have classified C. auris as an urgent threat to public health for the next decade due to its major clinical and economic impact and the lack of effective antifungal drugs and because of future projections concerning new C. auris infections. Importantly, the Global Antimicrobial Resistance Surveillance System (GLASS) has highlighted the need for more robust and efficacious global surveillance schemes enabling the identification and monitoring of antifungal resistance in Candida infections. Despite the clinical relevance of C. auris infections, our overall understanding of its pathophysiology and virulence, its response to human immune surveillance, and the molecular basis of multiple antifungal resistance remains in its infancy. Here, we show a marked phenotypic plasticity of C. auris clinical isolates. Further, we demonstrate critical roles of stress response mechanisms in regulating multidrug resistance and show that cell wall architecture and composition are key elements that determine antifungal drug susceptibilities. Our data promise new therapeutic options to treat drug-refractory C. auris infections.
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Day AM, Quinn J. Stress-Activated Protein Kinases in Human Fungal Pathogens. Front Cell Infect Microbiol 2019; 9:261. [PMID: 31380304 PMCID: PMC6652806 DOI: 10.3389/fcimb.2019.00261] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/04/2019] [Indexed: 11/28/2022] Open
Abstract
The ability of fungal pathogens to survive hostile environments within the host depends on rapid and robust stress responses. Stress-activated protein kinase (SAPK) pathways are conserved MAPK signaling modules that promote stress adaptation in all eukaryotic cells, including pathogenic fungi. Activation of the SAPK occurs via the dual phosphorylation of conserved threonine and tyrosine residues within a TGY motif located in the catalytic domain. This induces the activation and nuclear accumulation of the kinase and the phosphorylation of diverse substrates, thus eliciting appropriate cellular responses. The Hog1 SAPK has been extensively characterized in the model yeast Saccharomyces cerevisiae. Here, we use this a platform from which to compare SAPK signaling mechanisms in three major fungal pathogens of humans, Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. Despite the conservation of SAPK pathways within these pathogenic fungi, evidence is emerging that their role and regulation has significantly diverged. However, consistent with stress adaptation being a common virulence trait, SAPK pathways are important pathogenicity determinants in all these major human pathogens. Thus, the development of drugs which target fungal SAPKs has the exciting potential to generate broad-acting antifungal treatments.
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Affiliation(s)
- Alison M Day
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Janet Quinn
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
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Kabbara S, Hérivaux A, Dugé de Bernonville T, Courdavault V, Clastre M, Gastebois A, Osman M, Hamze M, Cock JM, Schaap P, Papon N. Diversity and Evolution of Sensor Histidine Kinases in Eukaryotes. Genome Biol Evol 2019; 11:86-108. [PMID: 30252070 PMCID: PMC6324907 DOI: 10.1093/gbe/evy213] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2018] [Indexed: 12/20/2022] Open
Abstract
Histidine kinases (HKs) are primary sensor proteins that act in cell signaling pathways generically referred to as "two-component systems" (TCSs). TCSs are among the most widely distributed transduction systems used by both prokaryotic and eukaryotic organisms to detect and respond to a broad range of environmental cues. The structure and distribution of HK proteins are now well documented in prokaryotes, but information is still fragmentary for eukaryotes. Here, we have taken advantage of recent genomic resources to explore the structural diversity and the phylogenetic distribution of HKs in the prominent eukaryotic supergroups. Searches of the genomes of 67 eukaryotic species spread evenly throughout the phylogenetic tree of life identified 748 predicted HK proteins. Independent phylogenetic analyses of predicted HK proteins were carried out for each of the major eukaryotic supergroups. This allowed most of the compiled sequences to be categorized into previously described HK groups. Beyond the phylogenetic analysis of eukaryotic HKs, this study revealed some interesting findings: 1) characterization of some previously undescribed eukaryotic HK groups with predicted functions putatively related to physiological traits; 2) discovery of HK groups that were previously believed to be restricted to a single kingdom in additional supergroups, and 3) indications that some evolutionary paths have led to the appearance, transfer, duplication, and loss of HK genes in some phylogenetic lineages. This study provides an unprecedented overview of the structure and distribution of HKs in the Eukaryota and represents a first step toward deciphering the evolution of TCS signaling in living organisms.
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Affiliation(s)
- Samar Kabbara
- Groupe d’Etude des Interactions Hôte-Pathogène, GEIHP, EA3142, Université d’Angers, SFR 4208 ICAT, France
| | - Anaïs Hérivaux
- Groupe d’Etude des Interactions Hôte-Pathogène, GEIHP, EA3142, Université d’Angers, SFR 4208 ICAT, France
| | | | - Vincent Courdavault
- Biomolécules et Biotechnologies Végétales, BBV, EA2106, Université François Rabelais de Tours, France
| | - Marc Clastre
- Biomolécules et Biotechnologies Végétales, BBV, EA2106, Université François Rabelais de Tours, France
| | - Amandine Gastebois
- Groupe d’Etude des Interactions Hôte-Pathogène, GEIHP, EA3142, Université d’Angers, SFR 4208 ICAT, France
| | - Marwan Osman
- Laboratoire Microbiologie Santé et Environnement, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
| | - Monzer Hamze
- Laboratoire Microbiologie Santé et Environnement, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
| | - J Mark Cock
- Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Université, UPMC Université Paris 06, CNRS, Roscoff, France
| | - Pauline Schaap
- School of Life Sciences, University of Dundee, United Kingdom
| | - Nicolas Papon
- Groupe d’Etude des Interactions Hôte-Pathogène, GEIHP, EA3142, Université d’Angers, SFR 4208 ICAT, France
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Mohanan VC, Chandarana PM, Chattoo BB, Patkar RN, Manjrekar J. Fungal Histidine Phosphotransferase Plays a Crucial Role in Photomorphogenesis and Pathogenesis in Magnaporthe oryzae. Front Chem 2017; 5:31. [PMID: 28580356 PMCID: PMC5437211 DOI: 10.3389/fchem.2017.00031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 05/04/2017] [Indexed: 11/13/2022] Open
Abstract
Two-component signal transduction (TCST) pathways play crucial roles in many cellular functions such as stress responses, biofilm formation, and sporulation. The histidine phosphotransferase (HPt), which is an intermediate phosphotransfer protein in a two-component system, transfers a phosphate group to a phosphorylatable aspartate residue in the target protein(s), and up-regulates stress-activated MAP kinase cascades. Most fungal genomes carry a single copy of the gene coding for HPt, which are potential antifungal targets. However, unlike the histidine kinases (HK) or the downstream response regulators (RR) in two-component system, the HPts have not been well-studied in phytopathogenic fungi. In this study, we investigated the role of HPt in the model rice-blast fungal pathogen Magnaporthe oryzae. We found that in M. oryzae an additional isoform of the HPT gene YPD1 was expressed specifically in response to light. Further, the expression of light-regulated genes such as those encoding envoy and blue-light-harvesting protein, and PAS domain containing HKs was significantly reduced upon down-regulation of YPD1 in M. oryzae. Importantly, down-regulation of YPD1 led to a significant decrease in the ability to penetrate the host cuticle and in light-dependent conidiation in M. oryzae. Thus, our results indicate that Ypd1 plays an important role in asexual development and host invasion, and suggest that YPD1 isoforms likely have distinct roles to play in the rice-blast pathogen M. oryzae.
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Affiliation(s)
- Varsha C Mohanan
- Bharat Chattoo Genome Research Centre, Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University of BarodaVadodara, India
| | - Pinal M Chandarana
- Bharat Chattoo Genome Research Centre, Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University of BarodaVadodara, India
| | - Bharat B Chattoo
- Bharat Chattoo Genome Research Centre, Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University of BarodaVadodara, India
| | - Rajesh N Patkar
- Bharat Chattoo Genome Research Centre, Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University of BarodaVadodara, India
| | - Johannes Manjrekar
- Bharat Chattoo Genome Research Centre, Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University of BarodaVadodara, India.,Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University of BarodaVadodara, India
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Desoubeaux G, Cray C. Rodent Models of Invasive Aspergillosis due to Aspergillus fumigatus: Still a Long Path toward Standardization. Front Microbiol 2017; 8:841. [PMID: 28559881 PMCID: PMC5432554 DOI: 10.3389/fmicb.2017.00841] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/24/2017] [Indexed: 01/09/2023] Open
Abstract
Invasive aspergillosis has been studied in laboratory by the means of plethora of distinct animal models. They were developed to address pathophysiology, therapy, diagnosis, or miscellaneous other concerns associated. However, there are great discrepancies regarding all the experimental variables of animal models, and a thorough focus on them is needed. This systematic review completed a comprehensive bibliographic analysis specifically-based on the technical features of rodent models infected with Aspergillus fumigatus. Out the 800 articles reviewed, it was shown that mice remained the preferred model (85.8% of the referenced reports), above rats (10.8%), and guinea pigs (3.8%). Three quarters of the models involved immunocompromised status, mainly by steroids (44.4%) and/or alkylating drugs (42.9%), but only 27.7% were reported to receive antibiotic prophylaxis to prevent from bacterial infection. Injection of spores (30.0%) and inhalation/deposition into respiratory airways (66.9%) were the most used routes for experimental inoculation. Overall, more than 230 distinct A. fumigatus strains were used in models. Of all the published studies, 18.4% did not mention usage of any diagnostic tool, like histopathology or mycological culture, to control correct implementation of the disease and to measure outcome. In light of these findings, a consensus discussion should be engaged to establish a minimum standardization, although this may not be consistently suitable for addressing all the specific aspects of invasive aspergillosis.
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Affiliation(s)
- Guillaume Desoubeaux
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA.,Service de Parasitologie-Mycologie-Médecine tropicale, Centre Hospitalier Universitaire de ToursTours, France.,Centre d'Etude des Pathologies Respiratoires (CEPR) Institut National de la Santé et de la Recherche Médicale U1100/Équipe 3, Université François-RabelaisTours, France
| | - Carolyn Cray
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA
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Yang Y, Chen M, Li Z, Al-Hatmi AMS, de Hoog S, Pan W, Ye Q, Bo X, Li Z, Wang S, Wang J, Chen H, Liao W. Genome Sequencing and Comparative Genomics Analysis Revealed Pathogenic Potential in Penicillium capsulatum as a Novel Fungal Pathogen Belonging to Eurotiales. Front Microbiol 2016; 7:1541. [PMID: 27761131 PMCID: PMC5051111 DOI: 10.3389/fmicb.2016.01541] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/14/2016] [Indexed: 01/31/2023] Open
Abstract
Penicillium capsulatum is a rare Penicillium species used in paper manufacturing, but recently it has been reported to cause invasive infection. To research the pathogenicity of the clinical Penicillium strain, we sequenced the genomes and transcriptomes of the clinical and environmental strains of P. capsulatum. Comparative analyses of these two P. capsulatum strains and close related strains belonging to Eurotiales were performed. The assembled genome sizes of P. capsulatum are approximately 34.4 Mbp in length and encode 11,080 predicted genes. The different isolates of P. capsulatum are highly similar, with the exception of several unique genes, INDELs or SNPs in the genes coding for glycosyl hydrolases, amino acid transporters and circumsporozoite protein. A phylogenomic analysis was performed based on the whole genome data of 38 strains belonging to Eurotiales. By comparing the whole genome sequences and the virulence-related genes from 20 important related species, including fungal pathogens and non-human pathogens belonging to Eurotiales, we found meaningful pathogenicity characteristics between P. capsulatum and its closely related species. Our research indicated that P. capsulatum may be a neglected opportunistic pathogen. This study is beneficial for mycologists, geneticists and epidemiologists to achieve a deeper understanding of the genetic basis of the role of P. capsulatum as a newly reported fungal pathogen.
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Affiliation(s)
- Ying Yang
- Beijing Institute of BiotechnologyBeijing, China; Beijing Institute of Radiation MedicineBeijing, China; National Institutes for Food and Drug ControlBeijing, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng HospitalShanghai, China; CBS-KNAW Fungal Biodiversity CentreUtrecht, Netherlands; Institute of Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands
| | - Zongwei Li
- Center for Hospital Infection Control, Chinese PLA Institute for Disease Control and Prevention Beijing, China
| | - Abdullah M S Al-Hatmi
- CBS-KNAW Fungal Biodiversity CentreUtrecht, Netherlands; Institute of Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands; Directorate General of Health Services, Ibri Hospital, Ministry of HealthIbri, Oman
| | - Sybren de Hoog
- CBS-KNAW Fungal Biodiversity CentreUtrecht, Netherlands; Institute of Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands
| | - Weihua Pan
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital Shanghai, China
| | - Qiang Ye
- National Institutes for Food and Drug ControlBeijing, China; Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech ProductsBeijing, China
| | - Xiaochen Bo
- Beijing Institute of Radiation Medicine Beijing, China
| | - Zhen Li
- Beijing Institute of Radiation Medicine Beijing, China
| | - Shengqi Wang
- Beijing Institute of Radiation Medicine Beijing, China
| | - Junzhi Wang
- National Institutes for Food and Drug Control Beijing, China
| | - Huipeng Chen
- Beijing Institute of Biotechnology Beijing, China
| | - Wanqing Liao
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital Shanghai, China
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Hérivaux A, So YS, Gastebois A, Latgé JP, Bouchara JP, Bahn YS, Papon N. Major Sensing Proteins in Pathogenic Fungi: The Hybrid Histidine Kinase Family. PLoS Pathog 2016; 12:e1005683. [PMID: 27467512 PMCID: PMC4965123 DOI: 10.1371/journal.ppat.1005683] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Anaïs Hérivaux
- Université d'Angers, Groupe d'Etude des Interactions Hôte-Pathogène, Angers, France
| | - Yee-Seul So
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Amandine Gastebois
- Université d'Angers, Groupe d'Etude des Interactions Hôte-Pathogène, Angers, France
| | | | - Jean-Philippe Bouchara
- Université d'Angers, Groupe d'Etude des Interactions Hôte-Pathogène, Angers, France
- Laboratoire de Parasitologie—Mycologie, Centre Hospitalier Universitaire d’Angers, Angers, France
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
- * E-mail: (YSB); (NP)
| | - Nicolas Papon
- Université d'Angers, Groupe d'Etude des Interactions Hôte-Pathogène, Angers, France
- * E-mail: (YSB); (NP)
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Albataineh MT, Kadosh D. Regulatory roles of phosphorylation in model and pathogenic fungi. Med Mycol 2015; 54:333-52. [PMID: 26705834 PMCID: PMC4818690 DOI: 10.1093/mmy/myv098] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/01/2015] [Indexed: 12/25/2022] Open
Abstract
Over the past 20 years, considerable advances have been made toward our understanding
of how post-translational modifications affect a wide variety of biological
processes, including morphology and virulence, in medically important fungi.
Phosphorylation stands out as a key molecular switch and regulatory modification that
plays a critical role in controlling these processes. In this article, we first
provide a comprehensive and up-to-date overview of the regulatory roles that both
Ser/Thr and non-Ser/Thr kinases and phosphatases play in model and pathogenic fungi.
Next, we discuss the impact of current global approaches that are being used to
define the complete set of phosphorylation targets (phosphoproteome) in medically
important fungi. Finally, we provide new insights and perspectives into the potential
use of key regulatory kinases and phosphatases as targets for the development of
novel and more effective antifungal strategies.
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Affiliation(s)
- Mohammad T Albataineh
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
| | - David Kadosh
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
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Valiante V, Macheleidt J, Föge M, Brakhage AA. The Aspergillus fumigatus cell wall integrity signaling pathway: drug target, compensatory pathways, and virulence. Front Microbiol 2015; 6:325. [PMID: 25932027 PMCID: PMC4399325 DOI: 10.3389/fmicb.2015.00325] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/31/2015] [Indexed: 01/06/2023] Open
Abstract
Aspergillus fumigatus is the most important airborne fungal pathogen, causing severe infections with invasive growth in immunocompromised patients. The fungal cell wall (CW) prevents the cell from lysing and protects the fungus against environmental stress conditions. Because it is absent in humans and because of its essentiality, the fungal CW is a promising target for antifungal drugs. Nowadays, compounds acting on the CW, i.e., echinocandin derivatives, are used to treat A. fumigatus infections. However, studies demonstrating the clinical effectiveness of echinocandins in comparison with antifungals currently recommended for first-line treatment of invasive aspergillosis are still lacking. Therefore, it is important to elucidate CW biosynthesis pathways and their signal transduction cascades, which potentially compensate the inhibition caused by CW- perturbing compounds. Like in other fungi, the central core of the cell wall integrity (CWI) signaling pathway in A. fumigatus is composed of three mitogen activated protein kinases. Deletion of these genes resulted in severely enhanced sensitivity of the mutants against CW-disturbing compounds and in drastic alterations of the fungal morphology. Additionally, several cross-talk interactions between the CWI pathways and other signaling pathways are emerging, raising the question about their role in the CW compensatory mechanisms. In this review we focused on recent advances in understanding the CWI signaling pathway in A. fumigatus and its role during drug stress response and virulence.
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Affiliation(s)
- Vito Valiante
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
| | - Juliane Macheleidt
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
| | - Martin Föge
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany ; Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Germany
| | - Axel A Brakhage
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany ; Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Germany
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Affiliation(s)
- Erika Shor
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
| | - Neeraj Chauhan
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- * E-mail:
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Guo L, Han L, Yang L, Zeng H, Fan D, Zhu Y, Feng Y, Wang G, Peng C, Jiang X, Zhou D, Ni P, Liang C, Liu L, Wang J, Mao C, Fang X, Peng M, Huang J. Genome and transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. cubense causing banana vascular wilt disease. PLoS One 2014; 9:e95543. [PMID: 24743270 PMCID: PMC3990668 DOI: 10.1371/journal.pone.0095543] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 03/28/2014] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND The asexual fungus Fusarium oxysporum f. sp. cubense (Foc) causing vascular wilt disease is one of the most devastating pathogens of banana (Musa spp.). To understand the molecular underpinning of pathogenicity in Foc, the genomes and transcriptomes of two Foc isolates were sequenced. METHODOLOGY/PRINCIPAL FINDINGS Genome analysis revealed that the genome structures of race 1 and race 4 isolates were highly syntenic with those of F. oxysporum f. sp. lycopersici strain Fol4287. A large number of putative virulence associated genes were identified in both Foc genomes, including genes putatively involved in root attachment, cell degradation, detoxification of toxin, transport, secondary metabolites biosynthesis and signal transductions. Importantly, relative to the Foc race 1 isolate (Foc1), the Foc race 4 isolate (Foc4) has evolved with some expanded gene families of transporters and transcription factors for transport of toxins and nutrients that may facilitate its ability to adapt to host environments and contribute to pathogenicity to banana. Transcriptome analysis disclosed a significant difference in transcriptional responses between Foc1 and Foc4 at 48 h post inoculation to the banana 'Brazil' in comparison with the vegetative growth stage. Of particular note, more virulence-associated genes were up regulated in Foc4 than in Foc1. Several signaling pathways like the mitogen-activated protein kinase Fmk1 mediated invasion growth pathway, the FGA1-mediated G protein signaling pathway and a pathogenicity associated two-component system were activated in Foc4 rather than in Foc1. Together, these differences in gene content and transcription response between Foc1 and Foc4 might account for variation in their virulence during infection of the banana variety 'Brazil'. CONCLUSIONS/SIGNIFICANCE Foc genome sequences will facilitate us to identify pathogenicity mechanism involved in the banana vascular wilt disease development. These will thus advance us develop effective methods for managing the banana vascular wilt disease, including improvement of disease resistance in banana.
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Affiliation(s)
- Lijia Guo
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | - Laying Yang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Huicai Zeng
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | | | | | - Guofen Wang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | | | | | | | - Changcong Liang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Lei Liu
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Jun Wang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Chao Mao
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | - Ming Peng
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Junsheng Huang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
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Kim JH, Mahoney N, Chan KL, Campbell BC, Haff RP, Stanker LH. Use of benzo analogs to enhance antimycotic activity of kresoxim methyl for control of aflatoxigenic fungal pathogens. Front Microbiol 2014; 5:87. [PMID: 24639673 PMCID: PMC3945611 DOI: 10.3389/fmicb.2014.00087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 02/18/2014] [Indexed: 01/27/2023] Open
Abstract
The aim of this study was to examine two benzo analogs, octylgallate (OG) and veratraldehyde (VT), as antifungal agents against strains of Aspergillus parasiticus and A.flavus (toxigenic or atoxigenic). Both toxigenic and atoxigenic strains used were capable of producing kojic acid, another cellular secondary product. A. fumigatus was used as a genetic model for this study. When applied independently, OG exhibits considerably higher antifungal activity compared to VT. The minimum inhibitory concentrations (MICs) of OG were 0.3–0.5 mM, while that of VT were 3.0–5.0 mM in agar plate-bioassays. OG or VT in concert with the fungicide kresoxim methyl (Kre-Me; strobilurin) greatly enhanced sensitivity of Aspergillus strains to Kre-Me. The combination with OG also overcame the tolerance of A. fumigatus mitogen-activated protein kinase (MAPK) mutants to Kre-Me. The degree of compound interaction resulting from chemosensitization of the fungi by OG was determined using checkerboard bioassays, where synergistic activity greatly lowered MICs or minimum fungicidal concentrations. However, the control chemosensitizer benzohydroxamic acid, an alternative oxidase inhibitor conventionally applied in concert with strobilurin, did not achieve synergism. The level of antifungal or chemosensitizing activity was also “compound—strain” specific, indicating differential susceptibility of tested strains to OG or VT, and/or heat stress. Besides targeting the antioxidant system, OG also negatively affected the cell wall-integrity pathway, as determined by the inhibition of Saccharomyces cerevisiae cell wall-integrity MAPK pathway mutants. We concluded that certain benzo analogs effectively inhibit fungal growth. They possess chemosensitizing capability to increase efficacy of Kre-Me and thus, could reduce effective dosages of strobilurins and alleviate negative side effects associated with current antifungal practices. OG also exhibits moderate antiaflatoxigenic activity.
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Affiliation(s)
- Jong H Kim
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
| | - Noreen Mahoney
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
| | - Kathleen L Chan
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
| | - Bruce C Campbell
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
| | - Ronald P Haff
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
| | - Larry H Stanker
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
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Hagiwara D, Takahashi-Nakaguchi A, Toyotome T, Yoshimi A, Abe K, Kamei K, Gonoi T, Kawamoto S. NikA/TcsC histidine kinase is involved in conidiation, hyphal morphology, and responses to osmotic stress and antifungal chemicals in Aspergillus fumigatus. PLoS One 2013; 8:e80881. [PMID: 24312504 PMCID: PMC3846623 DOI: 10.1371/journal.pone.0080881] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 10/05/2013] [Indexed: 11/18/2022] Open
Abstract
The fungal high osmolarity glycerol (HOG) pathway is composed of a two-component system (TCS) and Hog1-type mitogen-activated protein kinase (MAPK) cascade. A group III (Nik1-type) histidine kinase plays a major role in the HOG pathway of several filamentous fungi. In this study, we characterized a group III histidine kinase, NikA/TcsC, in the life-threatening pathogenic fungus, Aspergillus fumigatus. A deletion mutant of nikA showed low conidia production, abnormal hyphae, marked sensitivity to high osmolarity stresses, and resistance to cell wall perturbing reagents such as congo red and calcofluor white, as well as to fungicides such as fludioxonil, iprodione, and pyrrolnitrin. None of these phenotypes were observed in mutants of the SskA response regulator and SakA MAPK, which were thought to be downstream components of NikA. In contrast, in response to fludioxonil treatment, NikA was implicated in the phosphorylation of SakA MAPK and the transcriptional upregulation of catA, dprA, and dprB, which are regulated under the control of SakA. We then tested the idea that not only NikA, but also the other 13 histidine kinases play certain roles in the regulation of the HOG pathway. Interestingly, the expression of fos1, phkA, phkB, fhk5, and fhk6 increased by osmotic shock or fludioxonil treatment in a SakA-dependent manner. However, deletion mutants of the histidine kinases showed no significant defects in growth under the tested conditions. Collectively, although the signal transduction network related to NikA seems complicated, NikA plays a crucial role in several aspects of A. fumigatus physiology and, to a certain extent, modulates the HOG pathway.
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Affiliation(s)
- Daisuke Hagiwara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
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14
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Tebbets B, Yu Z, Stewart D, Zhao LX, Jiang Y, Xu LH, Andes D, Shen B, Klein B. Identification of antifungal natural products via Saccharomyces cerevisiae bioassay: insights into macrotetrolide drug spectrum, potency and mode of action. Med Mycol 2013; 51:280-9. [PMID: 22928922 PMCID: PMC3594352 DOI: 10.3109/13693786.2012.710917] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Since current antifungal drugs have not kept pace with the escalating medical demands of fungal infections, new, effective medications are required. However, antifungal drug discovery is hindered by the evolutionary similarity of mammalian and fungal cells, which results in fungal drug targets having human homologs and drug non-selectivity. The group III hybrid histidine kinases (HHKs) are an attractive drug target since they are conserved in fungi and absent in mammals. We used a Saccharomyces cerevisiae reporter strain that conditionally expresses HHK to establish a high-throughput bioassay to screen microbial extracts natural products for antifungals. We identified macrotetrolides, a group of related ionophores thought to exhibit restricted antifungal activity. In addition to confirming the use of this bioassay for the discovery of antifungal natural products, we demonstrated broader, more potent fungistatic activity of the macrotetrolides against multiple Candida spp., Cryptococcus spp., and Candida albicans in biofilms. Macrotetrolides were also active in an animal model of C. albicans biofilm, but were found to have inconsistent activity against fluconazole-resistant C. albicans, with most isolates resistant to this natural product. The macrotetrolides do not directly target HHKs, but their selective activity against S. cerevisiae grown in galactose (regardless of Drk1 expression) revealed potential new insight into the role of ion transport in the mode of action of these promising antifungal compounds. Thus, this simple, high-throughput bioassay permitted us to screen microbial extracts, identify natural products as antifungal drugs, and expand our understanding of the activity of macrotetrolides.
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Affiliation(s)
- Brad Tebbets
- Department of Pediatrics, the University of Wisconsin School of Medicine and Public Health, Madison, WI
- Department of Medical Microbiology and Immunology, the University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Zhiguo Yu
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, USA
| | - Douglas Stewart
- Department of Pediatrics, the University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Li-Xing Zhao
- Yunnan Institute of Microbiology, Yunnan University, Kunming, Yunnan, China
| | - Yi Jiang
- Yunnan Institute of Microbiology, Yunnan University, Kunming, Yunnan, China
| | - Li-Hua Xu
- Yunnan Institute of Microbiology, Yunnan University, Kunming, Yunnan, China
| | - David Andes
- Department of Internal Medicine, the University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Ben Shen
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, USA
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, Florida, USA
| | - Bruce Klein
- Department of Pediatrics, the University of Wisconsin School of Medicine and Public Health, Madison, WI
- Department of Internal Medicine, the University of Wisconsin School of Medicine and Public Health, Madison, WI
- Department of Medical Microbiology and Immunology, the University of Wisconsin School of Medicine and Public Health, Madison, WI
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15
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Grice CM, Bertuzzi M, Bignell EM. Receptor-mediated signaling in Aspergillus fumigatus. Front Microbiol 2013; 4:26. [PMID: 23430083 PMCID: PMC3576715 DOI: 10.3389/fmicb.2013.00026] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 02/01/2013] [Indexed: 11/15/2022] Open
Abstract
Aspergillus fumigatus is the most pathogenic species among the Aspergilli, and the major fungal agent of human pulmonary infection. To prosper in diverse ecological niches, Aspergilli have evolved numerous mechanisms for adaptive gene regulation, some of which are also crucial for mammalian infection. Among the molecules which govern such responses, integral membrane receptors are thought to be the most amenable to therapeutic modulation. This is due to the localization of these molecular sensors at the periphery of the fungal cell, and to the prevalence of small molecules and licensed drugs which target receptor-mediated signaling in higher eukaryotic cells. In this review we highlight the progress made in characterizing receptor-mediated environmental adaptation in A. fumigatus and its relevance for pathogenicity in mammals. By presenting a first genomic survey of integral membrane proteins in this organism, we highlight an abundance of putative seven transmembrane domain (7TMD) receptors, the majority of which remain uncharacterized. Given the dependency of A. fumigatus upon stress adaptation for colonization and infection of mammalian hosts, and the merits of targeting receptor-mediated signaling as an antifungal strategy, a closer scrutiny of sensory perception and signal transduction in this organism is warranted.
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Affiliation(s)
- C M Grice
- South Kensington Campus, Imperial College London London, UK
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16
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Current understanding of HOG-MAPK pathway in Aspergillus fumigatus. Mycopathologia 2012; 175:13-23. [PMID: 23161019 DOI: 10.1007/s11046-012-9600-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 11/04/2012] [Indexed: 10/27/2022]
Abstract
Aspergillus fumigatus is an important opportunistic fungal pathogen that causes lethal systemic invasive aspergillosis. It must be able to adapt to stress in the microenvironment during host invasion and systemic spread. The high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) signaling pathway is a key element that controls adaptation to environmental stress. It plays a critical role in the virulence of several fungal pathogens. In this review, we summarize the current knowledge about the functions of different components of the HOG-MAPK pathway in A. fumigatus through mutant analysis or inferences from the genome annotation, focusing on their roles in adaptation to stress, regulation of infection-related morphogenesis, and effect on virulence. We also briefly compare the functions of the HOG pathway in A. fumigatus with those in the model fungi Saccharomyces cerevisiae and Aspergillus nidulans as well as several other human and plant pathogens including Candida albicans, Cryptococcus neoformans, and Magnaporthe oryzae. The genes described in this review mainly include tcsB, fos1, skn7, sho1, pbs2, and sakA whose deletion mutants have already been established in A. fumigatus. Among them, fos1 has been considered a virulence factor in A. fumigatus, indicating that components of the HOG pathway may be suitable as targets for developing new fungicides. However, quite a few of the genes of this pathway, such as sskA (ssk1), sskB, steC, and downstream regulator genes, are not well characterized. System biology approaches may contribute to a more comprehensive understanding of HOG pathway functions with dynamic details.
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17
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Liu M, Machová E, Neščáková Z, Medovarská I, Clemons KV, Martinez M, Chen V, Bystrický S, Stevens DA. Vaccination with mannan protects mice against systemic aspergillosis. Med Mycol 2012; 50:818-28. [PMID: 22587733 DOI: 10.3109/13693786.2012.683539] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Invasive aspergillosis is a major cause of mortality in immunocompromised patients and therapeutic options are often limited, thus a vaccine would be desirable. We presently studied acid-stable cell-wall mannan (α-1, 6-linked backbone highly branched with α-1, 2; α-1, 3; and β-1, 2-linked manno-oligomers) derived from C. albicans, with or without conjugation to bovine serum albumin (BSA), as a vaccine against systemic aspergillosis. Mice were vaccinated subcutaneously with mannan or mannan-BSA conjugate weekly 3 times, ending 2 weeks prior to infection with A. fumigatus conidia. Results showed that the protection induced by mannan is dose-dependent; 12 mg unconjugated mannan alone or > 0.3 mg mannan-BSA consistently enhanced survival (P < 0.05). Fungal burdens in brains and kidneys were reduced after > 0.3 mg of mannan-BSA (all P < 0.05). Mannan-induced protection was improved about 40-fold by conjugation of BSA to mannan. Mannan-BSA (500 kDa) was more protective than 40 kDa mannan-BSA. Mannan is a candidate for a cross-protective conjugate fungal vaccine.
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Affiliation(s)
- Min Liu
- California Institute for Medical Research, San Jose, California, USA
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18
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Tebbets B, Stewart D, Lawry S, Nett J, Nantel A, Andes D, Klein BS. Identification and characterization of antifungal compounds using a Saccharomyces cerevisiae reporter bioassay. PLoS One 2012; 7:e36021. [PMID: 22574132 PMCID: PMC3344848 DOI: 10.1371/journal.pone.0036021] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 03/29/2012] [Indexed: 12/04/2022] Open
Abstract
New antifungal drugs are urgently needed due to the currently limited selection, the emergence of drug resistance, and the toxicity of several commonly used drugs. To identify drug leads, we screened small molecules using a Saccharomyces cerevisiae reporter bioassay in which S. cerevisiae heterologously expresses Hik1, a group III hybrid histidine kinase (HHK) from Magnaporthe grisea. Group III HHKs are integral in fungal cell physiology, and highly conserved throughout this kingdom; they are absent in mammals, making them an attractive drug target. Our screen identified compounds 13 and 33, which showed robust activity against numerous fungal genera including Candida spp., Cryptococcus spp. and molds such as Aspergillus fumigatus and Rhizopus oryzae. Drug-resistant Candida albicans from patients were also highly susceptible to compounds 13 and 33. While the compounds do not act directly on HHKs, microarray analysis showed that compound 13 induced transcripts associated with oxidative stress, and compound 33, transcripts linked with heavy metal stress. Both compounds were highly active against C. albicans biofilm, in vitro and in vivo, and exerted synergy with fluconazole, which was inactive alone. Thus, we identified potent, broad-spectrum antifungal drug leads from a small molecule screen using a high-throughput, S. cerevisiae reporter bioassay.
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Affiliation(s)
- Brad Tebbets
- The Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Microbiology Doctoral Training Program, The University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Douglas Stewart
- The Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Stephanie Lawry
- The Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- The Cellular and Molecular Pathology Program, The University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jeniel Nett
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Andre Nantel
- Biotechnology Research Institute, The National Research Council of Canada, Montreal, Quebec, Canada
| | - David Andes
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Bruce S. Klein
- The Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Internal Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
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19
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Kim JH, Chan KL, Faria NCG, Martins MDL, Campbell BC. Targeting the oxidative stress response system of fungi with redox-potent chemosensitizing agents. Front Microbiol 2012; 3:88. [PMID: 22438852 PMCID: PMC3305922 DOI: 10.3389/fmicb.2012.00088] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 02/22/2012] [Indexed: 11/28/2022] Open
Abstract
The cellular antioxidant system is a target in the antifungal action of amphotericin B (AMB) and itraconazole (ITZ), in filamentous fungi. The sakAΔ mutant of Aspergillus fumigatus, a mitogen-activated protein kinase (MAPK) gene deletion mutant in the antioxidant system, was found to be more sensitive to AMB or ITZ than other A. fumigatus strains, a wild type and a mpkCΔ mutant (a MAPK gene deletion mutant in the polyalcohol sugar utilization system). Complete fungal kill (≥99.9%) by ITZ or AMB was also achieved by much lower dosages for the sakAΔ mutant than for the other strains. It appears msnA, an Aspergillus ortholog to Saccharomyces cerevisiaeMSN2 (encoding a stress-responsive C2H2-type zinc-finger regulator) and sakA and/or mpkC (upstream MAPKs) are in the same stress response network under tert-butyl hydroperoxide (t-BuOOH)-, hydrogen peroxide (H2O2)- or AMB-triggered toxicity. Of note is that ITZ-sensitive yeast pathogens were also sensitive to t-BuOOH, showing a connection between ITZ sensitivity and antioxidant capacity of fungi. Enhanced antifungal activity of AMB or ITZ was achieved when these drugs were co-applied with redox-potent natural compounds, 2,3-dihydroxybenzaldehyde, thymol or salicylaldehyde, as chemosensitizing agents. We concluded that redox-potent compounds, which target the antioxidant system in fungi, possess a chemosensitizing capacity to enhance efficacy of conventional drugs.
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Affiliation(s)
- Jong H Kim
- Plant Mycotoxin Research Unit, Western Regional Research Center, USDA-ARS Albany, CA, USA
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20
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Disruption of the phospholipase D gene attenuates the virulence of Aspergillus fumigatus. Infect Immun 2011; 80:429-40. [PMID: 22083709 DOI: 10.1128/iai.05830-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Aspergillus fumigatus is the most prevalent airborne fungal pathogen that induces serious infections in immunocompromised patients. Phospholipases are key enzymes in pathogenic fungi that cleave host phospholipids, resulting in membrane destabilization and host cell penetration. However, knowledge of the impact of phospholipases on A. fumigatus virulence is rather limited. In this study, disruption of the pld gene encoding phospholipase D (PLD), an important member of the phospholipase protein family in A. fumigatus, was confirmed to significantly decrease both intracellular and extracellular PLD activity of A. fumigatus. The pld gene disruption did not alter conidial morphological characteristics, germination, growth, and biofilm formation but significantly suppressed the internalization of A. fumigatus into A549 epithelial cells without affecting conidial adhesion to epithelial cells. Importantly, the suppressed internalization was fully rescued in the presence of 100 μM phosphatidic acid, the PLD product. Indeed, complementation of pld restored the PLD activity and internalization capacity of A. fumigatus. Phagocytosis of A. fumigatus conidia by J774 macrophages was not affected by the absence of the pld gene. Pretreatment of conidia with 1-butanol and a specific PLD inhibitor decreased the internalization of A. fumigatus into A549 epithelial cells but had no effect on phagocytosis by J774 macrophages. Finally, loss of the pld gene attenuated the virulence of A. fumigatus in mice immunosuppressed with hydrocortisone acetate but not with cyclophosphamide. These data suggest that PLD of A. fumigatus regulates its internalization into lung epithelial cells and may represent an important virulence factor for A. fumigatus infection.
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Chemosensitization of aflatoxigenic fungi to antimycin A and strobilurin using salicylaldehyde, a volatile natural compound targeting cellular antioxidation system. Mycopathologia 2010; 171:291-8. [PMID: 20803256 DOI: 10.1007/s11046-010-9356-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 08/05/2010] [Indexed: 10/19/2022]
Abstract
Various species of fungi in the genus Aspergillus are the most common causative agents of invasive aspergillosis and/or producers of hepato-carcinogenic mycotoxins. Salicylaldehyde (SA), a volatile natural compound, exhibited potent antifungal and anti-mycotoxigenic activities to A. flavus and A. parasiticus. By exposure to the volatilized SA, the growth of A. parasiticus was inhibited up to 10-75% at 9.5 mM ≤ SA ≤ 16.0 mM, while complete growth inhibition was achieved at 19.0 mM ≤ SA. Similar trends were also observed with A. flavus. The aflatoxin production, i.e., aflatoxin B(1) and B(2) (AFB(1), AFB(2)) for A. flavus and AFB(1), AFB(2), AFG(1), and AFG(2) for A. parasiticus, in the SA-treated (9.5 mM) fungi was reduced by ~13-45% compared with the untreated control. Using gene deletion mutants of the model yeast Saccharomyces cerevisiae, we identified the fungal antioxidation system as the molecular target of SA, where sod1Δ [cytosolic superoxide dismutase (SOD)], sod2Δ (mitochondrial SOD), and glr1Δ (glutathione reductase) mutants showed increased sensitivity to this compound. Also sensitive was the gene deletion mutant, vph2Δ, for the vacuolar ATPase assembly protein, suggesting vacuolar detoxification plays an important role for fungal tolerance to SA. In chemosensitization experiments, co-application of SA with either antimycin A or strobilurin (inhibitors of mitochondrial respiration) resulted in complete growth inhibition of Aspergillus at much lower dose treatment of either agent, alone. Therefore, SA can enhance antifungal activity of commercial antifungal agents required to achieve effective control. SA is a potent antifungal and anti-aflatoxigenic volatile that may have some practical application as a fumigant.
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22
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Master and commander in fungal pathogens: the two-component system and the HOG signaling pathway. EUKARYOTIC CELL 2008; 7:2017-36. [PMID: 18952900 DOI: 10.1128/ec.00323-08] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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23
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Two-component signal transduction proteins as potential drug targets in medically important fungi. Infect Immun 2008; 76:4795-803. [PMID: 18765727 DOI: 10.1128/iai.00834-08] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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24
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Fedorova ND, Khaldi N, Joardar VS, Maiti R, Amedeo P, Anderson MJ, Crabtree J, Silva JC, Badger JH, Albarraq A, Angiuoli S, Bussey H, Bowyer P, Cotty PJ, Dyer PS, Egan A, Galens K, Fraser-Liggett CM, Haas BJ, Inman JM, Kent R, Lemieux S, Malavazi I, Orvis J, Roemer T, Ronning CM, Sundaram JP, Sutton G, Turner G, Venter JC, White OR, Whitty BR, Youngman P, Wolfe KH, Goldman GH, Wortman JR, Jiang B, Denning DW, Nierman WC. Genomic islands in the pathogenic filamentous fungus Aspergillus fumigatus. PLoS Genet 2008; 4:e1000046. [PMID: 18404212 PMCID: PMC2289846 DOI: 10.1371/journal.pgen.1000046] [Citation(s) in RCA: 357] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 03/04/2008] [Indexed: 01/23/2023] Open
Abstract
We present the genome sequences of a new clinical isolate of the important human pathogen, Aspergillus fumigatus, A1163, and two closely related but rarely pathogenic species, Neosartorya fischeri NRRL181 and Aspergillus clavatus NRRL1. Comparative genomic analysis of A1163 with the recently sequenced A. fumigatus isolate Af293 has identified core, variable and up to 2% unique genes in each genome. While the core genes are 99.8% identical at the nucleotide level, identity for variable genes can be as low 40%. The most divergent loci appear to contain heterokaryon incompatibility (het) genes associated with fungal programmed cell death such as developmental regulator rosA. Cross-species comparison has revealed that 8.5%, 13.5% and 12.6%, respectively, of A. fumigatus, N. fischeri and A. clavatus genes are species-specific. These genes are significantly smaller in size than core genes, contain fewer exons and exhibit a subtelomeric bias. Most of them cluster together in 13 chromosomal islands, which are enriched for pseudogenes, transposons and other repetitive elements. At least 20% of A. fumigatus-specific genes appear to be functional and involved in carbohydrate and chitin catabolism, transport, detoxification, secondary metabolism and other functions that may facilitate the adaptation to heterogeneous environments such as soil or a mammalian host. Contrary to what was suggested previously, their origin cannot be attributed to horizontal gene transfer (HGT), but instead is likely to involve duplication, diversification and differential gene loss (DDL). The role of duplication in the origin of lineage-specific genes is further underlined by the discovery of genomic islands that seem to function as designated “gene dumps” and, perhaps, simultaneously, as “gene factories”. Aspergillus is an extremely diverse genus of filamentous ascomycetous fungi (molds) found ubiquitously in soil and decomposing vegetation. Being supreme opportunists, aspergilli have adapted to overcome various chemical, physical, and biological stresses found in heterogeneous environments. While most species in the genus are saprophytes, a surprising number are able to infect wounded plants and animals. Remarkably, the allergic human host also responds abnormally to the aspergilli with lung and sinus disease. The advent of immunosuppressive agents and other medical advances have created a large worldwide pool of human hosts susceptible to some Aspergillus species, including the world's most harmful mold and the causative agent of invasive aspergillosis, Aspergillus fumigatus. In this study, we have used the power of comparative genomics to gain insight into genetic mechanisms that may contribute to the metabolic versatility and pathogenicity of this important human pathogen. Comparison of the genomes of two A. fumigatus clinical isolates and two closely related, but rarely pathogenic species showed that their genomes contain several large isolate- and species-specific chromosomal islands. The metabolic capabilities encoded by these highly labile regions are likely to contribute to their rapid adaptation to heterogeneous environments such as soil or a living host.
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Affiliation(s)
- Natalie D. Fedorova
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Nora Khaldi
- Department of Genetics, Smurfit Institute, University of Dublin, Trinity College, Dublin, Ireland
| | - Vinita S. Joardar
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Rama Maiti
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Paolo Amedeo
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Michael J. Anderson
- School of Medicine and Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Jonathan Crabtree
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Joana C. Silva
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Jonathan H. Badger
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Ahmed Albarraq
- School of Medicine and Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Sam Angiuoli
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Howard Bussey
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Paul Bowyer
- School of Medicine and Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Peter J. Cotty
- Agricultural Research Service, United States Department of Agriculture, Department of Plant Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Paul S. Dyer
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Amy Egan
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Kevin Galens
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | | | - Brian J. Haas
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Jason M. Inman
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Richard Kent
- School of Medicine and Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Sebastien Lemieux
- Institute for Research in Immunology and Cancer, Department of Computer Science and Operations Research, Universite de Montreal, Montreal, Canada
| | - Iran Malavazi
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Joshua Orvis
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Terry Roemer
- Merck & Co., Inc., Whitehouse Station, New Jersey, United States of America
| | | | - Jaideep P. Sundaram
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Granger Sutton
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Geoff Turner
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - J. Craig Venter
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Owen R. White
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Brett R. Whitty
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Phil Youngman
- Merck & Co., Inc., Whitehouse Station, New Jersey, United States of America
| | - Kenneth H. Wolfe
- Department of Genetics, Smurfit Institute, University of Dublin, Trinity College, Dublin, Ireland
| | - Gustavo H. Goldman
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Jennifer R. Wortman
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Bo Jiang
- Merck & Co., Inc., Whitehouse Station, New Jersey, United States of America
| | - David W. Denning
- School of Medicine and Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - William C. Nierman
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
- Department of Biochemistry and Molecular Biology, The George Washington University School of Medicine, Washington DC, United States of America
- * E-mail:
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25
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Capilla J, Clemons KV, Stevens DA. Animal models: an important tool in mycology. Med Mycol 2007; 45:657-84. [PMID: 18027253 PMCID: PMC7107685 DOI: 10.1080/13693780701644140] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 08/22/2007] [Indexed: 10/29/2022] Open
Abstract
Animal models of fungal infections are, and will remain, a key tool in the advancement of the medical mycology. Many different types of animal models of fungal infection have been developed, with murine models the most frequently used, for studies of pathogenesis, virulence, immunology, diagnosis, and therapy. The ability to control numerous variables in performing the model allows us to mimic human disease states and quantitatively monitor the course of the disease. However, no single model can answer all questions and different animal species or different routes of infection can show somewhat different results. Thus, the choice of which animal model to use must be made carefully, addressing issues of the type of human disease to mimic, the parameters to follow and collection of the appropriate data to answer those questions being asked. This review addresses a variety of uses for animal models in medical mycology. It focuses on the most clinically important diseases affecting humans and cites various examples of the different types of studies that have been performed. Overall, animal models of fungal infection will continue to be valuable tools in addressing questions concerning fungal infections and contribute to our deeper understanding of how these infections occur, progress and can be controlled and eliminated.
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Affiliation(s)
- Javier Capilla
- California Institute for Medical Research, San Jose, USA
- Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, USA
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Karl V. Clemons
- California Institute for Medical Research, San Jose, USA
- Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, USA
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - David A. Stevens
- California Institute for Medical Research, San Jose, USA
- Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center, San Jose, USA
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
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Banno S, Noguchi R, Yamashita K, Fukumori F, Kimura M, Yamaguchi I, Fujimura M. Roles of putative His-to-Asp signaling modules HPT-1 and RRG-2, on viability and sensitivity to osmotic and oxidative stresses in Neurospora crassa. Curr Genet 2007; 51:197-208. [PMID: 17211673 DOI: 10.1007/s00294-006-0116-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 12/15/2006] [Accepted: 12/17/2006] [Indexed: 10/23/2022]
Abstract
Neurospora crassa has a putative histidine phosphotransfer protein (HPT-1) that transfers signals from 11 histidine kinases to two putative response regulators (RRG-1 and RRG-2) in its histidine-to-aspartate phosphorelay system. The hpt-1 gene was successfully disrupted in the os-2 (MAP kinase gene) mutant, but not in the wild-type strain in this study. Crossing the resultant hpt-1; os-2 mutants with the wild-type or os-1 (histidine kinase gene) mutant strains produced no progeny with hpt-1 or os-1; hpt-1 mutation, strongly suggesting that hpt-1 is essential for growth unless downstream OS-2 is inactivated. hpt-1 mutation partially recovered the osmotic sensitivity of os-2 mutants, implying the involvement of yeast Skn7-like RRG-2 in osmoregulation. However, the rrg-2 disruption did not change the osmotic sensitivity of the wild-type strain and the os-2 mutant, suggesting that rrg-2 did not participate in the osmoregulation. Both rrg-2 and os-2 single mutation slightly increased sensitivity to t-butyl hydroperoxide, and rrg-2 and hpt-1 mutations increased the os-2 mutant's sensitivity. Although OS-1 is considered as a positive regulator of OS-2 MAP kinase, our results suggested that HPT-1 negatively regulated downstream MAP kinase cascade, and that OS-2 and RRG-2 probably participate independently in the oxidative stress response in N. crassa.
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Affiliation(s)
- Shinpei Banno
- Faculty of Life Sciences, Toyo University, Itakura, Oura-gun, Gunma 374-0193, Japan
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27
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Chapeland-Leclerc F, Paccallet P, Ruprich-Robert G, Reboutier D, Chastin C, Papon N. Differential involvement of histidine kinase receptors in pseudohyphal development, stress adaptation, and drug sensitivity of the opportunistic yeast Candida lusitaniae. EUKARYOTIC CELL 2007; 6:1782-94. [PMID: 17660361 PMCID: PMC2043395 DOI: 10.1128/ec.00155-07] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fungal histidine kinase receptors (HKRs) sense and transduce many extracellular signals. We investigated the role of HKRs in morphogenetic transition, osmotolerance, oxidative stress response, and mating ability in the opportunistic yeast Candida lusitaniae. We isolated three genes, SLN1, NIK1, and CHK1, potentially encoding HKRs of classes VI, III, and X, respectively. These genes were disrupted by a transformation system based upon the "URA3 blaster" strategy. Functional analysis of disruptants was undertaken, except for the sln1 nik1 double mutant and the sln1 nik1 chk1 triple mutant, which are not viable in C. lusitaniae. The sln1 mutant revealed a high sensitivity to oxidative stress, whereas both the nik1 and chk1 mutants exhibited a more moderate sensitivity to peroxide. We also showed that the NIK1 gene was implicated in phenylpyrrole and dicarboximide compound susceptibility while HKRs seem not to be involved in resistance toward antifungals of clinical relevance. Concerning mating ability, all disruptants were still able to reproduce sexually in vitro in unilateral or bilateral crosses. The most important result of this study was that the sln1 mutant displayed a global defect of pseudohyphal differentiation, especially in high-osmolarity and oxidative-stress conditions. Thus, the SLN1 gene could be crucial for the C. lusitaniae yeast-to-pseudohypha morphogenetic transition. This implication is strengthened by a high level of SLN1 mRNAs revealed by semiquantitative reverse transcription-PCR when the yeast develops pseudohyphae. Our findings highlight a differential contribution of the three HKRs in osmotic and oxidant adaptation during the morphological transition in C. lusitaniae.
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Affiliation(s)
- Florence Chapeland-Leclerc
- Programme Chimiorésistance des Levures Pathogènes, EA209 Eucaryotes Pathogènes: Transports Membranaires et Chimiorésistance, UFR des Sciences Pharmaceutiques et Biologiques, Université Paris-Descartes, 75006, Paris, France.
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28
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Wang L, Ma L, Leng W, Liu T, Yu L, Yang J, Yang L, Zhang W, Zhang Q, Dong J, Xue Y, Zhu Y, Xu X, Wan Z, Ding G, Yu F, Tu K, Li Y, Li R, Shen Y, Jin Q. Analysis of the dermatophyte Trichophyton rubrum expressed sequence tags. BMC Genomics 2006; 7:255. [PMID: 17032460 PMCID: PMC1621083 DOI: 10.1186/1471-2164-7-255] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2006] [Accepted: 10/11/2006] [Indexed: 11/20/2022] Open
Abstract
Background Dermatophytes are the primary causative agent of dermatophytoses, a disease that affects billions of individuals worldwide. Trichophyton rubrum is the most common of the superficial fungi. Although T. rubrum is a recognized pathogen for humans, little is known about how its transcriptional pattern is related to development of the fungus and establishment of disease. It is therefore necessary to identify genes whose expression is relevant to growth, metabolism and virulence of T. rubrum. Results We generated 10 cDNA libraries covering nearly the entire growth phase and used them to isolate 11,085 unique expressed sequence tags (ESTs), including 3,816 contigs and 7,269 singletons. Comparisons with the GenBank non-redundant (NR) protein database revealed putative functions or matched homologs from other organisms for 7,764 (70%) of the ESTs. The remaining 3,321 (30%) of ESTs were only weakly similar or not similar to known sequences, suggesting that these ESTs represent novel genes. Conclusion The present data provide a comprehensive view of fungal physiological processes including metabolism, sexual and asexual growth cycles, signal transduction and pathogenic mechanisms.
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Affiliation(s)
- Lingling Wang
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Li Ma
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Wenchuan Leng
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Tao Liu
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Lu Yu
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Jian Yang
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Li Yang
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Wenliang Zhang
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Qian Zhang
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Jie Dong
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Ying Xue
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Yafang Zhu
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Xingye Xu
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
| | - Zhe Wan
- Research Centre for Medical Mycology, Beijing 100034, China
| | - Guohui Ding
- Bioinformatics Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Fudong Yu
- Bioinformatics Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Kang Tu
- Bioinformatics Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yixue Li
- Bioinformatics Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ruoyu Li
- Research Centre for Medical Mycology, Beijing 100034, China
| | - Yan Shen
- Chinese National Human Genome Center, Beijing, Beijing 100176, China
| | - Qi Jin
- State Key Lab for Molecular Virology and Genetic Engineering, Beijing 100176, China
- The Institute of Pathogen Microbiology, Chinese Academy of Medical Science, Beijing 100730, China
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Clemons KV, Espiritu M, Parmar R, Stevens DA. Comparative efficacies of conventional amphotericin b, liposomal amphotericin B (AmBisome), caspofungin, micafungin, and voriconazole alone and in combination against experimental murine central nervous system aspergillosis. Antimicrob Agents Chemother 2006; 49:4867-75. [PMID: 16304147 PMCID: PMC1315954 DOI: 10.1128/aac.49.12.4867-4875.2005] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Central nervous system (CNS) aspergillosis is a severe disease that responds poorly to current therapies. The current studies examined the efficacies of several antifungal agents alone or in combination with a murine model of CNS aspergillosis. Immunosuppressed mice were infected intracerebrally with Aspergillus fumigatus and treated with an amphotericin B preparation, an echinocandin, or voriconazole (VCZ) given alone or in combination. Monotherapy studies showed that micafungin (MICA), caspofungin (CAS), VCZ, conventional amphotericin B (AMB), Abelcet (ABLC) (a lipid-carried AMB formulation; Enzon Pharmaceuticals, Inc.), and AmBisome (AmBi) (liposomal AMB; Gilead Sciences, Inc.) were efficacious. However, doses of AmBi above 15 mg/kg of body weight showed reduced efficacy. Neither MICA nor CAS showed dose responsiveness at the doses tested (1, 5, or 10 mg/kg). Only the 40-mg/kg dose of VCZ was effective. AmBi and ABLC showed dose responsiveness, with 10-mg/kg doses causing a significant reduction in fungal burden; they had equivalent activities at the 10-mg/kg dose. Suboptimal dosages of AmBi in combination with MICA, CAS, or VCZ were effective in prolonging survival. However, significantly enhanced activity was demonstrated only with AmBi and VCZ in combination. AmBi in combination with MICA or CAS showed a trend toward enhanced activity, but the combination was not significantly superior to monotherapy. The use of AmBi with CAS or VCZ at optimal doses did not improve efficacy. Cure was not attained with any dosage combinations. These results indicate that AmBi in combination with VCZ may be superior for treatment of CNS aspergillosis; combinations of AmBi and MICA or CAS were not antagonistic and may have a slight benefit.
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Affiliation(s)
- Karl V Clemons
- California Institute for Medical Research, Division of Infectious Diseases, Santa Clara Valley Medical Center, 751 South Bascom Ave., San Jose, California 95128-2699, USA.
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30
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Zhang L, Wang M, Li R, Calderone R. Expression of Aspergillus fumigatus virulence-related genes detected in vitro and in vivo with competitive RT-PCR. Mycopathologia 2006; 160:201-6. [PMID: 16205968 DOI: 10.1007/s11046-005-0141-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Accepted: 06/22/2005] [Indexed: 12/19/2022]
Abstract
We have measured the transcription of several genes that have been implicated as virulence factors in Aspergillus fumigatus, including fos-1, a histidine kinase, two-component signal protein, rhbA, a ras-related protein required for signaling, pksP, a polyketide synthase involved in biosynthesis of melanin, pabA synthetase, an enzyme catalyzing a late step in the biosynthesis of folate, lysF, a homoconitase related to lysine biosynthesis, and cpcA, the transcriptional activator of the cross-pathway control system of amino acid biosynthesis. Transcription levels were determined from in vitro grown organism as well as from lung tissue from mice infected with A. fumigatus. Our data indicate that fos-1 and rhbA transcription increased significantly during the infection in mice, compared to the other genes whose transcription remained the same (pksP, cpcA, pabA) or decreased slightly (lysF). In vitro measurements of transcription compared to transcription in infected lung tissue demonstrated low levels of fos-1 and rhbA, 20-40-fold increases (cpcA, lysF, pabA), while pksP was not detected from cultures. Our data demonstrate that transcription of these genes differs in vitro versus during disease.
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Affiliation(s)
- Lijuan Zhang
- Department of Dermatology/Research Center of Medical Mycology, Peking University First Hospital, Beijing, China
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31
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Imai J, Singh G, Fernandez B, Clemons KV, Stevens DA. Efficacy of Abelcet and caspofungin, alone or in combination, against CNS aspergillosis in a murine model. J Antimicrob Chemother 2005; 56:166-71. [PMID: 15917284 DOI: 10.1093/jac/dki178] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Currently, few options exist to treat central nervous system (CNS) aspergillosis, which is usually fatal. We tested the efficacy of Abelcet and caspofungin, alone and in combination for treatment of this disease. METHODS Male CD-1 mice were immunosuppressed with 200 mg/kg cyclophosphamide 2 days prior to infection and every 5 days thereafter. In the first study, mice were infected intracerebrally with 2.1 x 10(6) conidia/mouse of Aspergillus fumigatus; 10 days of once daily therapy began one day later. Groups of 10 received 0.8, 4, or 8 mg/kg of Abelcet, intravenously (iv), or caspofungin, intraperitoneally, 0.8 mg/kg of conventional amphotericin B (AmB) iv, or no treatment. In a second study, mice were challenged with 6.4 x 10(6) conidia and given no treatment, 8 mg/kg of Abelcet or caspofungin, alone or in combination. On day 14, cfu were determined in survivors by plating of organ homogenates. RESULTS In the first study, mice given any regimen of Abelcet or caspofungin had a survival rate > or =80% whereas untreated had 90% mortality. All drug regimens prolonged survival (P < or = 0.0008) and reduced cfu (P < or = 0.0001-0.003) recovered from the brains and kidneys compared with untreated. Abelcet showed an apparent dose-related reduction of cfu in the brains. Abelcet at 4 or 8 mg/kg were equivalent to AmB in reducing cfu from both organs (P > 0.05); AmB was superior to 0.8 mg/kg of Abelcet in the brain only (P < 0.02). Abelcet at 8 mg/kg or AmB at 0.8 mg/kg were superior to all regimens of caspofungin in reducing cfu (P < or = 0.05-0.001). In the second study, Abelcet alone significantly prolonged survival and reduced cfu in the organs versus the controls. Caspofungin did not significantly prolong survival or reduce cfu in comparison with the controls. In combination, Abelcet and caspofungin were equivalent to Abelcet alone. CONCLUSIONS Abelcet proved to be efficacious, but not curative, in the treatment of CNS aspergillosis and was equivalent overall to conventional AmB. Caspofungin was not as effective against the larger inoculum, but did not enhance or interfere with the efficacy of Abelcet. Since Abelcet displayed dose-responsive efficacy, it is possible higher doses could produce superior results, yet not show toxicity.
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Affiliation(s)
- Jackie Imai
- California Institute for Medical Research, San Jose, 95128, USA
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32
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Singh G, Imai J, Clemons KV, Stevens DA. Efficacy of caspofungin against central nervous system Aspergillus fumigatus infection in mice determined by TaqMan PCR and CFU methods. Antimicrob Agents Chemother 2005; 49:1369-76. [PMID: 15793114 PMCID: PMC1068651 DOI: 10.1128/aac.49.4.1369-1376.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We have reported previously that prolonged caspofungin (CAS) dosing enhances survival in a murine model of central nervous system aspergillosis. In this study we determined by quantitative PCR (qPCR) and CFU enumeration whether CAS could reduce fungal burdens, prior to the deaths of untreated animals, and also assessed progressive infection in untreated mice. Mice were infected intracranially and treated for 4 days with CAS (1, 5, or 10 mg/kg of body weight/day) or amphotericin B (AMB) (3 mg/kg/day) starting 1 day postinfection. Fungal burdens in brains and kidneys of untreated controls were determined on days 1, 3, and 5 to assess progressive infection; burdens in treated animals were determined on day 5. qPCR showed higher burdens than CFU enumeration in all comparisons. In untreated animals, qPCR showed transiently increased burdens in brains, while CFU enumeration showed a decrease. qPCR showed increased burdens in kidneys, but CFU enumeration did not. Neither method indicated drug efficacy in the brain. Both methods showed AMB efficacy in the kidneys, and qPCR demonstrated CAS efficacy at all doses. Spearman correlations of qPCR and CFU determination results showed a significant correlation for most untreated groups; results correlated well for kidneys (P < or = 0.03) but not for brains in treated mice. Regression analyses of qPCR and CFU groups indicated different slopes for progressive infection in untreated animals but the same slopes for CAS dose-response efficacy. qPCR appeared to better reflect the progression of untreated infection. The lack of demonstration of efficacy in the brain suggests that longer dosing is necessary to cause burden reduction. These results also suggest that, when there is drug efficacy in a therapeutic study, either method appears to be useful for determining Aspergillus fumigatus burdens.
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Affiliation(s)
- Gaurav Singh
- California Institute for Medical Research, California, USA
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33
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Du C, Calderone R, Richert J, Li D. Deletion of the SSK1 response regulator gene in Candida albicans contributes to enhanced killing by human polymorphonuclear neutrophils. Infect Immun 2005; 73:865-71. [PMID: 15664927 PMCID: PMC547022 DOI: 10.1128/iai.73.2.865-871.2005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The isolation and partial functional characterization of the two-component response regulator SSK1 gene of Candida albicans was previously reported. Compared to wild-type (CAF2-1) and gene-reconstituted (SSK23) strains, the ssk1 null strain (SSK21) was avirulent in a murine model of hematogenously disseminated candidiasis and less able to adhere to human esophageal cells. More recent data indicate that SSK21 is sensitive to 4 to 8 mM H(2)O(2) in vitro than CAF2-1 and SSK23. Furthermore, microarray studies indicate that the regulation of two classes of genes, those encoding cell wall functions and stress adaptation, are altered in the ssk1 mutant. In the present study, the susceptibility of strains CAF2-1, SSK21, and SSK23 to killing by human polymorphonuclear neutrophils (PMNs) was assessed. Results are also described for a newly constructed ssk1 mutant (SSK24) in which the URA3 gene is integrated into its native locus. Our results indicate that killing of SSK21 and SSK24 was significantly greater than that of CAF2-1 and SSK23 (P < 0.01). In order to determine why Ssk1p at least partially protects the organism against the killing activity of human PMNs, we compared the signal transduction activity and the inflammatory response gene profiles of PMNs infected with either the wild type or the ssk1 mutant. Phosphorylation of the mitogen-activated protein kinases p42/44 and p38 from neutrophils infected with either CAF2-1 (wild type) or SSK21 (ssk1/ssk1) was similar, while expression and phosphorylation of the JNK mitogen-activated protein kinase was not observed following infection with either strain. On the other hand, we observed an upregulation of seven inflammatory response genes in PMNs infected with the SSK21 mutant only, while an increase in interleukin-10 expression was measured in PMNs infected with either strain. Downregulation of interleukin-2 was observed in PMNs infected with either strain. Verification of the transcriptional profiling was obtained by reverse transcription-PCR for three of the genes that were upregulated in neutrophils infected with the ssk1 mutant. Also, the sensitivity of strain SSK21 to human defensin-1, one of the nonoxidative, antimicrobial peptides of PMNs, was greater than that of CAF2-1, demonstrating that nonoxidative killing in PMNs may contribute to the increased susceptibility of the ssk1 mutant. Our results indicate that the Ssk1p response regulator protein may provide at least partial adaptive functions for the survival of C. albicans following its encounter with human neutrophils.
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Affiliation(s)
- Chen Du
- Department of Microbiology and Immunology, Georgetown University Medical Center, 312 SE Med Dent Building, 3900 Reservoir Road NW, Washington, DC 20057-2197, USA
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Borkovich KA, Alex LA, Yarden O, Freitag M, Turner GE, Read ND, Seiler S, Bell-Pedersen D, Paietta J, Plesofsky N, Plamann M, Goodrich-Tanrikulu M, Schulte U, Mannhaupt G, Nargang FE, Radford A, Selitrennikoff C, Galagan JE, Dunlap JC, Loros JJ, Catcheside D, Inoue H, Aramayo R, Polymenis M, Selker EU, Sachs MS, Marzluf GA, Paulsen I, Davis R, Ebbole DJ, Zelter A, Kalkman ER, O'Rourke R, Bowring F, Yeadon J, Ishii C, Suzuki K, Sakai W, Pratt R. Lessons from the genome sequence of Neurospora crassa: tracing the path from genomic blueprint to multicellular organism. Microbiol Mol Biol Rev 2004; 68:1-108. [PMID: 15007097 PMCID: PMC362109 DOI: 10.1128/mmbr.68.1.1-108.2004] [Citation(s) in RCA: 434] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We present an analysis of over 1,100 of the approximately 10,000 predicted proteins encoded by the genome sequence of the filamentous fungus Neurospora crassa. Seven major areas of Neurospora genomics and biology are covered. First, the basic features of the genome, including the automated assembly, gene calls, and global gene analyses are summarized. The second section covers components of the centromere and kinetochore complexes, chromatin assembly and modification, and transcription and translation initiation factors. The third area discusses genome defense mechanisms, including repeat induced point mutation, quelling and meiotic silencing, and DNA repair and recombination. In the fourth section, topics relevant to metabolism and transport include extracellular digestion; membrane transporters; aspects of carbon, sulfur, nitrogen, and lipid metabolism; the mitochondrion and energy metabolism; the proteasome; and protein glycosylation, secretion, and endocytosis. Environmental sensing is the focus of the fifth section with a treatment of two-component systems; GTP-binding proteins; mitogen-activated protein, p21-activated, and germinal center kinases; calcium signaling; protein phosphatases; photobiology; circadian rhythms; and heat shock and stress responses. The sixth area of analysis is growth and development; it encompasses cell wall synthesis, proteins important for hyphal polarity, cytoskeletal components, the cyclin/cyclin-dependent kinase machinery, macroconidiation, meiosis, and the sexual cycle. The seventh section covers topics relevant to animal and plant pathogenesis and human disease. The results demonstrate that a large proportion of Neurospora genes do not have homologues in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. The group of unshared genes includes potential new targets for antifungals as well as loci implicated in human and plant physiology and disease.
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Affiliation(s)
- Katherine A Borkovich
- Department of Plant Pathology, University of California, Riverside, California 92521, USA. Katherine/
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