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Liu F, Zeng M, Zhou X, Huang F, Song Z. Aspergillus fumigatus escape mechanisms from its harsh survival environments. Appl Microbiol Biotechnol 2024; 108:53. [PMID: 38175242 DOI: 10.1007/s00253-023-12952-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 10/09/2023] [Accepted: 10/19/2023] [Indexed: 01/05/2024]
Abstract
Aspergillus fumigatus is a ubiquitous pathogenic mold and causes several diseases, including mycotoxicosis, allergic reactions, and systemic diseases (invasive aspergillosis), with high mortality rates. In its ecological niche, the fungus has evolved and mastered many reply strategies to resist and survive against negative threats, including harsh environmental stress and deficiency of essential nutrients from natural environments, immunity responses and drug treatments in host, and competition from symbiotic microorganisms. Hence, treating A. fumigatus infection is a growing challenge. In this review, we summarized A. fumigatus reply strategies and escape mechanisms and clarified the main competitive or symbiotic relationships between A. fumigatus, viruses, bacteria, or fungi in host microecology. Additionally, we discussed the contemporary drug repertoire used to treat A. fumigatus and the latest evidence of potential resistance mechanisms. This review provides valuable knowledge which will stimulate further investigations and clinical applications for treating and preventing A. fumigatus infections. KEY POINTS: • Harsh living environment was a great challenge for A. fumigatus survival. • A. fumigatus has evolved multiple strategies to escape host immune responses. • A. fumigatus withstands antifungal drugs via intrinsic escape mechanisms.
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Affiliation(s)
- Fangyan Liu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Meng Zeng
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
- Department of Clinical Laboratory, Yongchuan Hospital of Chongqing Medical University, Chongqing, 402160, People's Republic of China
| | - Xue Zhou
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Fujiao Huang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Zhangyong Song
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China.
- Molecular Biotechnology Platform, Public Center of Experimental Technology, Southwest Medical University, Luzhou, 646000, People's Republic of China.
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Anwar S, Alrumaihi F, Sarwar T, Babiker AY, Khan AA, Prabhu SV, Rahmani AH. Exploring Therapeutic Potential of Catalase: Strategies in Disease Prevention and Management. Biomolecules 2024; 14:697. [PMID: 38927099 PMCID: PMC11201554 DOI: 10.3390/biom14060697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
The antioxidant defense mechanisms play a critical role in mitigating the deleterious effects of reactive oxygen species (ROS). Catalase stands out as a paramount enzymatic antioxidant. It efficiently catalyzes the decomposition of hydrogen peroxide (H2O2) into water and oxygen, a potentially harmful byproduct of cellular metabolism. This reaction detoxifies H2O2 and prevents oxidative damage. Catalase has been extensively studied as a therapeutic antioxidant. Its applications range from direct supplementation in conditions characterized by oxidative stress to gene therapy approaches to enhance endogenous catalase activity. The enzyme's stability, bioavailability, and the specificity of its delivery to target tissues are significant hurdles. Furthermore, studies employing conventional catalase formulations often face issues related to enzyme purity, activity, and longevity in the biological milieu. Addressing these challenges necessitates rigorous scientific inquiry and well-designed clinical trials. Such trials must be underpinned by sound experimental designs, incorporating advanced catalase formulations or novel delivery systems that can overcome existing limitations. Enhancing catalase's stability, specificity, and longevity in vivo could unlock its full therapeutic potential. It is necessary to understand the role of catalase in disease-specific contexts, paving the way for precision antioxidant therapy that could significantly impact the treatment of diseases associated with oxidative stress.
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Affiliation(s)
- Shehwaz Anwar
- Department of Medical Laboratory Technology, Mohan Institute of Nursing and Paramedical Sciences, Mohan Group of Institutions, Bareilly 243302, India;
| | - Faris Alrumaihi
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | - Tarique Sarwar
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | - Ali Yousif Babiker
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | - Amjad Ali Khan
- Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | - Sitrarasu Vijaya Prabhu
- Department of Biotechnology, Microbiology and Bioinformatics, National College (Autonomous), Tiruchirapalli 620001, India;
| | - Arshad Husain Rahmani
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
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Dishliyska V, Stoyancheva G, Abrashev R, Miteva-Staleva J, Spasova B, Angelova M, Krumova E. Catalase from the Antarctic Fungus Aspergillus fumigatus I-9-Biosynthesis and Gene Characterization. Indian J Microbiol 2023; 63:541-548. [PMID: 38031622 PMCID: PMC10682308 DOI: 10.1007/s12088-023-01110-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/07/2023] [Indexed: 12/01/2023] Open
Abstract
Extremely cold habitats are a serious challenge for the existing there organisms. Inhabitants of these conditions are mostly microorganisms and lower mycetae. The mechanisms of microbial adaptation to extreme conditions are still unclear. Low temperatures cause significant physiological and biochemical changes in cells. Recently, there has been increasing interest in the relationship between low-temperature exposure and oxidative stress events, as well as the importance of antioxidant enzymes for survival in such conditions. The catalase is involved in the first line of the cells' antioxidant defense. Published information supports the concept of a key role for catalase in antioxidant defense against cold stress in a wide range of organisms isolated from the Antarctic. Data on representatives of microscopic fungi, however, are rarely found. There is scarce information on the characterization of catalase synthesized by adapted to cold stress organisms. Overall, this study aimed to observe the role of catalase in the survival strategy of filamentous fungi in extremely cold habitats and to identify the gene encoded catalase enzyme. Our results clearly showed that catalase is the main part of antioxidant enzyme defense in fungal cells against oxidative stress caused by low temperature exposure.
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Affiliation(s)
- Vladislava Dishliyska
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Galina Stoyancheva
- Departament of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Radoslav Abrashev
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Jeny Miteva-Staleva
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Boriana Spasova
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Maria Angelova
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Ekaterina Krumova
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
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Schruefer S, Pschibul A, Wong SSW, Sae-Ong T, Wolf T, Schäuble S, Panagiotou G, Brakhage AA, Aimanianda V, Kniemeyer O, Ebel F. Distinct transcriptional responses to fludioxonil in Aspergillus fumigatus and its ΔtcsC and Δskn7 mutants reveal a crucial role for Skn7 in the cell wall reorganizations triggered by this antifungal. BMC Genomics 2023; 24:684. [PMID: 37964194 PMCID: PMC10647056 DOI: 10.1186/s12864-023-09777-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 10/31/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus is a major fungal pathogen that causes severe problems due to its increasing resistance to many therapeutic agents. Fludioxonil is a compound that triggers a lethal activation of the fungal-specific High Osmolarity Glycerol pathway. Its pronounced antifungal activity against A. fumigatus and other pathogenic molds renders this agent an attractive lead substance for the development of new therapeutics. The group III hydride histidine kinase TcsC and its downstream target Skn7 are key elements of the multistep phosphorelay that represents the initial section of the High Osmolarity Glycerol pathway. Loss of tcsC results in resistance to fludioxonil, whereas a Δskn7 mutant is partially, but not completely resistant. RESULTS In this study, we compared the fludioxonil-induced transcriptional responses in the ΔtcsC and Δskn7 mutant and their parental A. fumigatus strain. The number of differentially expressed genes correlates well with the susceptibility level of the individual strains. The wild type and, to a lesser extend also the Δskn7 mutant, showed a multi-faceted stress response involving genes linked to ribosomal and peroxisomal function, iron homeostasis and oxidative stress. A marked difference between the sensitive wild type and the largely resistant Δskn7 mutant was evident for many cell wall-related genes and in particular those involved in the biosynthesis of chitin. Biochemical data corroborate this differential gene expression that does not occur in response to hyperosmotic stress. CONCLUSIONS Our data reveal that fludioxonil induces a strong and TcsC-dependent stress that affects many aspects of the cellular machinery. The data also demonstrate a link between Skn7 and the cell wall reorganizations that foster the characteristic ballooning and the subsequent lysis of fludioxonil-treated cells.
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Affiliation(s)
- Sebastian Schruefer
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, Germany
| | - Annica Pschibul
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Sarah Sze Wah Wong
- UMR2000, Molecular Mycology Unit, Mycology Department, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
| | - Tongta Sae-Ong
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Thomas Wolf
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Sascha Schäuble
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Gianni Panagiotou
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Axel A Brakhage
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Vishukumar Aimanianda
- UMR2000, Molecular Mycology Unit, Mycology Department, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
- Institut Pasteur, Université Paris Cité, Immunobiology of Aspergillus, Mycology Department, Paris, France
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Frank Ebel
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, Germany.
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Park J, Lee HH, Moon H, Lee N, Kim S, Kim JE, Lee Y, Min K, Kim H, Choi GJ, Lee YW, Seo YS, Son H. A combined transcriptomic and physiological approach to understanding the adaptive mechanisms to cope with oxidative stress in Fusarium graminearum. Microbiol Spectr 2023; 11:e0148523. [PMID: 37671872 PMCID: PMC10581207 DOI: 10.1128/spectrum.01485-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/04/2023] [Indexed: 09/07/2023] Open
Abstract
In plant-pathogen interactions, oxidative bursts are crucial for plants to defend themselves against pathogen infections. Rapid production and accumulation of reactive oxygen species kill pathogens directly and cause local cell death, preventing pathogens from spreading to adjacent cells. Meanwhile, the pathogens have developed several mechanisms to tolerate oxidative stress and successfully colonize plant tissues. In this study, we investigated the mechanisms responsible for resistance to oxidative stress by analyzing the transcriptomes of six oxidative stress-sensitive strains of the plant pathogenic fungus Fusarium graminearum. Weighted gene co-expression network analysis identified several pathways related to oxidative stress responses, including the DNA repair system, autophagy, and ubiquitin-mediated proteolysis. We also identified hub genes with high intramodular connectivity in key modules and generated deletion or conditional suppression mutants. Phenotypic characterization of those mutants showed that the deletion of FgHGG4, FgHGG10, and FgHGG13 caused sensitivity to oxidative stress, and further investigation on those genes revealed that transcriptional elongation and DNA damage responses play roles in oxidative stress response and pathogenicity. The suppression of FgHGL7 also led to hypersensitivity to oxidative stress, and we demonstrated that FgHGL7 plays a crucial role in heme biosynthesis and is essential for peroxidase activity. This study increases the understanding of the adaptive mechanisms to cope with oxidative stress in plant pathogenic fungi. IMPORTANCE Fungal pathogens have evolved various mechanisms to overcome host-derived stresses for successful infection. Oxidative stress is a representative defense system induced by the host plant, and fungi have complex response systems to cope with it. Fusarium graminearum is one of the devastating plant pathogenic fungi, and understanding its pathosystem is crucial for disease control. In this study, we investigated adaptive mechanisms for coping with oxidative stress at the transcriptome level using oxidative stress-sensitive strains. In addition, by introducing genetic modification technique such as CRISPR-Cas9 and the conditional gene expression system, we identified pathways/genes required for resistance to oxidative stress and also for virulence. Overall, this study advances the understanding of the oxidative stress response and related mechanisms in plant pathogenic fungi.
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Affiliation(s)
- Jiyeun Park
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Hyun-Hee Lee
- Department of Integrated Biological Science, Pusan National University, Busan, Republic of Korea
| | - Heeji Moon
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Nahyun Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Sieun Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Jung-Eun Kim
- Research Institute of Climate Change and Agriculture, National Institute of Horticultural and Herbal Science, Jeju, Republic of Korea
| | - Yoonji Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Kyunghun Min
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Hun Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea
| | - Gyung Ja Choi
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Young-Su Seo
- Department of Integrated Biological Science, Pusan National University, Busan, Republic of Korea
| | - Hokyoung Son
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
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Venugopalan LP, Aimanianda V, Namperumalsamy VP, Prajna L, Kuppamuthu D, Jayapal JM. Comparative proteome analysis identifies species-specific signature proteins in Aspergillus pathogens. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12559-4. [PMID: 37166481 DOI: 10.1007/s00253-023-12559-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 04/22/2023] [Accepted: 04/25/2023] [Indexed: 05/12/2023]
Abstract
Aspergillus flavus and Aspergillus fumigatus are important human pathogens that can infect the lung and cornea. During infection, Aspergillus dormant conidia are the primary morphotype that comes in contact with the host. As the conidial surface-associated proteins (CSPs) and the extracellular proteins during the early stages of growth play a crucial role in establishing infection, we profiled and compared these proteins between a clinical strain of A. flavus and a clinical strain of A. fumigatus. We identified nearly 100 CSPs in both Aspergillus, and these non-covalently associated surface proteins were able to stimulate the neutrophils to secrete interleukin IL-8. Mass spectrometry analysis identified more than 200 proteins in the extracellular space during the early stages of conidial growth and germination (early exoproteome). The conidial surface proteins and the early exoproteome of A. fumigatus were enriched with immunoreactive proteins and those with pathogenicity-related functions while that of the A. flavus were primarily enzymes involved in cell wall reorganization and binding. Comparative proteome analysis of the CSPs and the early exoproteome between A. flavus and A. fumigatus enabled the identification of a common core proteome and potential species-specific signature proteins. Transcript analysis of selected proteins indicate that the transcript-protein level correlation does not exist for all proteins and might depend on factors such as membrane-anchor signals and protein half-life. The probable signature proteins of A. flavus and A. fumigatus identified in this study can serve as potential candidates for developing species-specific diagnostic tests. KEY POINTS: • CSPs and exoproteins could differentiate A. flavus and A. fumigatus. • A. fumigatus conidial surface harbored more antigenic proteins than A. flavus. • Identified species-specific signature proteins of A. flavus and A. fumigatus.
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Affiliation(s)
- Lakshmi Prabha Venugopalan
- Department of Proteomics, Aravind Medical Research Foundation, Anna Nagar, Madurai, Tamil Nadu, India
- Present address: Centre for Biotechnology, Anna University, Chennai, India
| | - Vishukumar Aimanianda
- Unité des Aspergillus, Institut Pasteur, 75015, Paris, France
- Present address: Unité de recherche Mycologie Moléculaire, UMR2000, Institut Pasteur, 75015, Paris, France
| | | | - Lalitha Prajna
- Department of Ocular Microbiology, Aravind Medical Research Foundation, Anna Nagar, Madurai, Tamil Nadu, India
| | - Dharmalingam Kuppamuthu
- Department of Proteomics, Aravind Medical Research Foundation, Anna Nagar, Madurai, Tamil Nadu, India
| | - Jeya Maheshwari Jayapal
- Department of Proteomics, Aravind Medical Research Foundation, Anna Nagar, Madurai, Tamil Nadu, India.
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de Carvalho Patricio BF, da Silva Lopes Pereira JO, Sarcinelli MA, de Moraes BPT, Rocha HVA, Gonçalves-de-Albuquerque CF. Could the Lung Be a Gateway for Amphotericin B to Attack the Army of Fungi? Pharmaceutics 2022; 14:2707. [PMID: 36559201 PMCID: PMC9784761 DOI: 10.3390/pharmaceutics14122707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/07/2022] Open
Abstract
Fungal diseases are a significant cause of morbidity and mortality worldwide, primarily affecting immunocompromised patients. Aspergillus, Pneumocystis, and Cryptococcus are opportunistic fungi and may cause severe lung disease. They can develop mechanisms to evade the host immune system and colonize or cause lung disease. Current fungal infection treatments constitute a few classes of antifungal drugs with significant fungi resistance development. Amphotericin B (AmB) has a broad-spectrum antifungal effect with a low incidence of resistance. However, AmB is a highly lipophilic antifungal with low solubility and permeability and is unstable in light, heat, and oxygen. Due to the difficulty of achieving adequate concentrations of AmB in the lung by intravenous administration and seeking to minimize adverse effects, nebulized AmB has been used. The pulmonary pathway has advantages such as its rapid onset of action, low metabolic activity at the site of action, ability to avoid first-pass hepatic metabolism, lower risk of adverse effects, and thin thickness of the alveolar epithelium. This paper presented different strategies for pulmonary AmB delivery, detailing the potential of nanoformulation and hoping to foster research in the field. Our finds indicate that despite an optimistic scenario for the pulmonary formulation of AmB based on the encouraging results discussed here, there is still no product registration on the FDA nor any clinical trial undergoing ClinicalTrial.gov.
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Affiliation(s)
- Beatriz Ferreira de Carvalho Patricio
- Pharmacology Laboratory, Biomedical Institute, Federal University of State of Rio de Janeiro, 94 Frei Caneca Street, Rio de Janeiro 20211-010, Brazil
- Postgraduate Program in Molecular and Cell Biology, Biomedical Institute, Federal University of State of Rio de Janeiro, 94 Frei Caneca Street, Rio de Janeiro 20211-010, Brazil
| | | | - Michelle Alvares Sarcinelli
- Laboratory of Micro and Nanotechnology, Institute of Technology of Drugs, Oswaldo Cruz Foundation, Brazil Av., 4036, Rio de Janeiro 213040-361, Brazil
| | - Bianca Portugal Tavares de Moraes
- Postgraduate Program in Biotechnology, Biology Institute, Federal Fluminense University, Rua Prof. Marcos Waldemar de Freitas Reis, Niterói 24210-201, Brazil
- Immunopharmacology Laboratory, Biomedical Institute, Federal University of State of Rio de Janeiro, 94 Frei Caneca Street, Rio de Janeiro 20211-010, Brazil
| | - Helvécio Vinicius Antunes Rocha
- Laboratory of Micro and Nanotechnology, Institute of Technology of Drugs, Oswaldo Cruz Foundation, Brazil Av., 4036, Rio de Janeiro 213040-361, Brazil
| | - Cassiano Felippe Gonçalves-de-Albuquerque
- Postgraduate Program in Molecular and Cell Biology, Biomedical Institute, Federal University of State of Rio de Janeiro, 94 Frei Caneca Street, Rio de Janeiro 20211-010, Brazil
- Postgraduate Program in Biotechnology, Biology Institute, Federal Fluminense University, Rua Prof. Marcos Waldemar de Freitas Reis, Niterói 24210-201, Brazil
- Immunopharmacology Laboratory, Biomedical Institute, Federal University of State of Rio de Janeiro, 94 Frei Caneca Street, Rio de Janeiro 20211-010, Brazil
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Transcriptional Stages of Conidia Germination and Associated Genes in Aspergillus flavus: An Essential Role for Redox Genes. Toxins (Basel) 2022; 14:toxins14080560. [PMID: 36006223 PMCID: PMC9412981 DOI: 10.3390/toxins14080560] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/04/2022] [Accepted: 08/12/2022] [Indexed: 12/03/2022] Open
Abstract
Aflatoxin is a threatening mycotoxin primarily present in the agricultural environment, especially in food and feedstuff, and poses significant global health risks. Aflatoxins are produced mainly by Aspergillus flavus. Conidia germination is the first step for A. flavus development. In this study, the transcriptome of A. flavus conidia was analyzed at three different stages of conidia germination, which were characterized by two different microscopes. Dormant conidia grew isotropically with the cell size increasing up to 5 h of after being inoculated in a liquid medium. Conidia changed towards polarized growth from 5 to 10 h of germination, during which germ tubes formed. Moreover, transcriptome analyses revealed that a larger number of genes changed in the isotropic growth stages compared to polarized growth, with 1910 differentially expressed genes (DEGs) up-regulated and 969 DEGs down-regulated in isotropic growth. GO and KEGG pathway analyses and pathway enrichment demonstrated that, in the isotropic growth stage, the top three pathways were translation, amino acid and carbohydrate metabolism. The ribosome was a key pathway in translation, as RPS28e, RPL53 and RPL36e were the top three DEGs. For polarized growth stage, lipid metabolism, amino acid metabolism and carbohydrate metabolism were the top three most active pathways. POX1 from alpha-linolenic acid metabolism was a DEG in lipid metabolism as well. Genes related to the antioxidant system were crucial for conidia germination. Furthermore, RT-PCR results showed the same trends as the transcriptome for redox genes, and essential oils have a significant inhibitory effect on germination rate and redox gene expression. Therefore, redox genes play an important role during germination, and the disruption of redox genes is involved in the mechanism of action of coumalic acid and geraniol against A. flavus spore germination.
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Nguyen PT, Wacker T, Brown AJP, da Silva Dantas A, Shekhova E. Understanding the Role of Nitronate Monooxygenases in Virulence of the Human Fungal Pathogen Aspergillus fumigatus. J Fungi (Basel) 2022; 8:736. [PMID: 35887491 PMCID: PMC9323177 DOI: 10.3390/jof8070736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 12/23/2022] Open
Abstract
Aspergillus fumigatus is the leading cause of the fungal invasive disease called aspergillosis, which is associated with a high mortality rate that can reach 50% in some groups of immunocompromised individuals. The increasing prevalence of azole-resistant A. fumigatus isolates, both in clinical settings and the environment, highlights the importance of discovering new fungal virulence factors that can potentially become targets for novel antifungals. Nitronate monooxygenases (Nmos) represent potential targets for antifungal compounds as no orthologs of those enzymes are present in humans. Nmos catalyse the denitrification of nitroalkanes, thereby detoxifying these mediators of nitro-oxidative stress, and therefore we tested whether Nmos provide protection for A. fumigatus against host-imposed stresses at sites of infection. The results of inhibition zone assays indicated that Nmo2 and Nmo5 are not essential for the oxidative stress resistance of A. fumigatus in vitro. In addition, the resazurin-based metabolic activity assay revealed that the growth of mutants lacking the nmo2 or nmo5 genes was only slightly reduced in the presence of 0.05 mM peroxynitrite. Nevertheless, both Nmo2 and Nmo5 were shown to contribute to defense against murine bone marrow-derived macrophages, and this was no longer observed when NADPH oxidase, the main generator of reactive oxygen species during infection, was inhibited in macrophages. Furthermore, we revealed that Nnmos promote the virulence of the fungus in the Galleria mellonella model of infection. Both nmo2 and nmo5 knock-out strains were less virulent than the wild-type control as recorded 72 h post-infection. Our results indicate that Nmos play a role in the virulence of A. fumigatus.
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Bavadharani S, Premamalini T, Karthika K, Kindo AJ. In Vitro Production of Virulence Factors and Antifungal Susceptibility Pattern of Aspergillus Isolates from Clinical Samples in a Tertiary Care Center. J Lab Physicians 2022; 14:479-484. [DOI: 10.1055/s-0042-1747680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
Abstract
Objectives This study was aimed to investigate the association between virulence factors and antifungal susceptibility pattern among Aspergillus species.
Materials and Methods This study was carried out in the Department of Microbiology, from May 2018 to June 2019. A total of 52 Aspergillus isolates obtained from various clinical samples were speciated based on microscopic identification by lacto phenol cotton blue (LPCB) mount and slide culture technique. The production of virulence factors such as biofilm, lipase, phospholipase, amylase, and hemolysin were detected using standard phenotypic methods with Aspergillus niger ATCC (American Type Culture Collection) 6275 as the control strain. Antifungal susceptibility patterns of all Aspergillus isolates to amphotericin B, itraconazole, voriconazole, and posaconazole were evaluated in line with the Clinical Laboratory Standards Institute (CLSI) M38-A2 guidelines.
Results The percentage of resistance was the highest in itraconazole (48.08%), followed by amphotericin B (28.85%) and voriconazole (9.62%). All amphotericin B-resistant isolates produced biofilm, itraconazole-resistant isolates exhibited phospholipase activity, and voriconazole-resistant isolates produced biofilm and demonstrated phospholipase and hemolytic activities. Regardless of the virulence factors produced, all isolates were susceptible to posaconazole.
Conclusion Understanding the relationship between virulence factors and antifungal resistance aids in the development of new therapeutic approaches involving virulence mechanisms as potential targets for effective antifungal drug development.
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Affiliation(s)
- Sukumar Bavadharani
- Department of Microbiology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Porur, Chennai, India
| | - Thayanidhi Premamalini
- Department of Microbiology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Porur, Chennai, India
| | - Kanagasabapathi Karthika
- Department of Microbiology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Porur, Chennai, India
| | - Anupma Jyoti Kindo
- Department of Microbiology, Sri Ramachandra Medical College & Research Institute, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Porur, Chennai, India
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Akiyama DY, Rocha MC, Costa JH, Teles CB, da Silva Zuccoli G, Malavazi I, Fill TP. The Penicillium brasilianum Histone Deacetylase Clr3 Regulates Secondary Metabolite Production and Tolerance to Oxidative Stress. J Fungi (Basel) 2022; 8:jof8050514. [PMID: 35628769 PMCID: PMC9146837 DOI: 10.3390/jof8050514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 02/01/2023] Open
Abstract
Most of the biosynthetic gene clusters (BGCs) found in microbes are silent under standard laboratory cultivation conditions due to the lack of expression triggering stimuli, representing a considerable drawback in drug discovery. To access the full biosynthetic potential, studies towards the activation of cryptic BGCs are essential. Histone acetylation status is an important regulator of chromatin structure, which impacts cell physiology and the expression of BGCs. In this study, clr3, a gene encoding a histone deacetylase in Penicillium brasilianum LaBioMMi 136, is deleted and associated phenotypic and metabolic changes are evaluated. The results indicate reduced growth under oxidative stress conditions in the ∆clr3 strain, higher intracellular reactive oxygen species (ROS) levels, and a different transcriptional profile of 13 ROS-related genes of both strains under basal and ROS-induced conditions. Moreover, the production of 14 secondary metabolites, including austin-related meroterpenoids, brasiliamides, verruculogen, penicillic acid, and cyclodepsipeptides was evaluated in the ∆clr3 strain, most of them being reduced. Accordingly, the addition of epigenetic modulators responsible for HDAC inhibition into P. brasilianum’s growth media also culminated in the reduction in secondary metabolite production. The results suggest that Clr3 plays an essential role in secondary metabolite biosynthesis in P. brasilianum, thus offering new strategies for the regulation of natural product synthesis by assessing chromatin modification.
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Affiliation(s)
- Daniel Yuri Akiyama
- Department of Organic Chemistry, Institute of Chemistry, State University of Campinas, Campinas 13083-970, SP, Brazil; (D.Y.A.); (J.H.C.)
| | - Marina Campos Rocha
- Department of Genetic and Evolution, Federal University of São Carlos, São Carlos 13565-905, SP, Brazil;
| | - Jonas Henrique Costa
- Department of Organic Chemistry, Institute of Chemistry, State University of Campinas, Campinas 13083-970, SP, Brazil; (D.Y.A.); (J.H.C.)
| | - Caroline Brandão Teles
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas, Campinas 13083-970, SP, Brazil; (C.B.T.); (G.d.S.Z.)
| | - Giuliana da Silva Zuccoli
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas, Campinas 13083-970, SP, Brazil; (C.B.T.); (G.d.S.Z.)
| | - Iran Malavazi
- Department of Genetic and Evolution, Federal University of São Carlos, São Carlos 13565-905, SP, Brazil;
- Correspondence: (I.M.); (T.P.F.)
| | - Taicia Pacheco Fill
- Department of Organic Chemistry, Institute of Chemistry, State University of Campinas, Campinas 13083-970, SP, Brazil; (D.Y.A.); (J.H.C.)
- Correspondence: (I.M.); (T.P.F.)
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12
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Margalit A, Sheehan D, Carolan JC, Kavanagh K. Exposure to the Pseudomonas aeruginosa secretome alters the proteome and secondary metabolite production of Aspergillus fumigatus. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001164. [PMID: 35333152 PMCID: PMC9558348 DOI: 10.1099/mic.0.001164] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/16/2022] [Indexed: 01/09/2023]
Abstract
The fungal pathogen Aspergillus fumigatus is frequently cultured from the sputum of cystic fibrosis (CF) patients along with the bacterium Pseudomonas aeruginosa. A. fumigatus secretes a range of secondary metabolites, and one of these, gliotoxin, has inhibitory effects on the host immune response. The effect of P. aeruginosa culture filtrate (CuF) on fungal growth and gliotoxin production was investigated. Exposure of A. fumigatus hyphae to P. aeruginosa cells induced increased production of gliotoxin and a decrease in fungal growth. In contrast, exposure of A. fumigatus hyphae to P. aeruginosa CuF led to increased growth and decreased gliotoxin production. Quantitative proteomic analysis was used to characterize the proteomic response of A. fumigatus upon exposure to P. aeruginosa CuF. Changes in the profile of proteins involved in secondary metabolite biosynthesis (e.g. gliotoxin, fumagillin, pseurotin A), and changes to the abundance of proteins involved in oxidative stress (e.g. formate dehydrogenase) and detoxification (e.g. thioredoxin reductase) were observed, indicating that the bacterial secretome had a profound effect on the fungal proteome. Alterations in the abundance of proteins involved in detoxification and oxidative stress highlight the ability of A. fumigatus to differentially regulate protein synthesis in response to environmental stresses imposed by competitors such as P. aeruginosa. Such responses may ultimately have serious detrimental effects on the host.
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Affiliation(s)
- Anatte Margalit
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - David Sheehan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - James C. Carolan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Co. Kildare, Ireland
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13
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The Protective Role of 1,8-Dihydroxynaphthalene-Melanin on Conidia of the Opportunistic Human Pathogen Aspergillus fumigatus Revisited: No Role in Protection against Hydrogen Peroxide and Superoxides. mSphere 2022; 7:e0087421. [PMID: 34986316 PMCID: PMC8730813 DOI: 10.1128/msphere.00874-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Previously, 1,8-dihydroxynaphthalene (DHN)-melanin was described to protect Aspergillus fumigatus against hydrogen peroxide (H2O2), thereby protecting this opportunistic human pathogen from reactive oxygen species generated by the immune system. This was based on the finding that the ATCC 46645 mutant with mutations in the pksP gene of the DHN-melanin synthesis pathway showed increased sensitivity to reactive oxygen species compared to the wild type. Here, it is shown that deletion of the pksP gene in A. fumigatus strain CEA10 did not affect sensitivity for H2O2 and superoxide in a plate stress assay. In addition, direct exposure of the dormant white conidia of the pksP deletion strains to H2O2 did not result in increased sensitivity. Moreover, complementation of the ATCC 46645 pksP mutant strain with the wild-type pksP gene did result in pigmented conidia but did not rescue the H2O2-sensitive phenotype observed in the plate stress assay. Genome sequencing of the ATCC 46645 pksP mutant strain and its complemented strain revealed a mutation in the cat1 gene, likely due to the UV mutagenesis procedure used previously, which could explain the increased sensitivity toward H2O2. In summary, DHN-melanin is not involved in protection against H2O2 or superoxide and, thus, has no role in survival of conidia when attacked by these reactive oxygen species. IMPORTANCE Opportunistic pathogens like Aspergillus fumigatus have strategies to protect themselves against reactive oxygen species like hydrogen peroxides and superoxides that are produced by immune cells. DHN-melanin is the green pigment on conidia of Aspergillus fumigatus and more than 2 decades ago was reported to protect conidia against hydrogen peroxide. Here, we correct this misinterpretation by showing that DHN-melanin actually is not involved in protection of conidia against hydrogen peroxide. We show that UV mutagenesis that was previously used to select a pksP mutant generated many more genome-wide mutations. We discovered that a mutation in the mycelial catalase gene cat1 could explain the observed phenotype of increased hydrogen peroxide sensitivity. Our work shows that UV mutagenesis is not the preferred methodology to be used for generating mutants. It requires genome sequencing with single-nucleotide polymorphism analysis as well as additional validations to discard unwanted and confirm correct phenotypes.
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14
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Talaromyces marneffei Infection: Virulence, Intracellular Lifestyle and Host Defense Mechanisms. J Fungi (Basel) 2022; 8:jof8020200. [PMID: 35205954 PMCID: PMC8880324 DOI: 10.3390/jof8020200] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/14/2022] [Accepted: 02/18/2022] [Indexed: 12/02/2022] Open
Abstract
Talaromycosis (Penicilliosis) is an opportunistic mycosis caused by the thermally dimorphic fungus Talaromyces (Penicillium) marneffei. Similar to other major causes of systemic mycoses, the extent of disease and outcomes are the results of complex interactions between this opportunistic human pathogen and a host’s immune response. This review will highlight the current knowledge regarding the dynamic interaction between T. marneffei and mammalian hosts, particularly highlighting important aspects of virulence factors, intracellular lifestyle and the mechanisms of immune defense as well as the strategies of the pathogen for manipulating and evading host immune cells.
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15
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Stoyancheva G, Dishliyska V, Miteva‐Staleva J, Kostadinova N, Abrashev R, Angelova M, Krumova E. Sequencing and gene expression analysis of catalase genes in Antarctic fungal strain Penicillium griseofulvum P29. Polar Biol 2022. [DOI: 10.1007/s00300-021-03001-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Yuan P, Qian W, Jiang L, Jia C, Ma X, Kang Z, Liu J. A secreted catalase contributes to Puccinia striiformis resistance to host-derived oxidative stress. STRESS BIOLOGY 2021; 1:22. [PMID: 37676381 PMCID: PMC10441885 DOI: 10.1007/s44154-021-00021-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/22/2021] [Indexed: 09/08/2023]
Abstract
Plants can produce reactive oxygen species (ROS) to counteract pathogen invasion, and pathogens have also evolved corresponding ROS scavenging strategies to promote infection and pathogenicity. Catalases (CATs) have been found to play pivotal roles in detoxifying H2O2 formed by superoxide anion catalyzed by superoxide dismutases (SODs). However, few studies have addressed H2O2 removing during rust fungi infection of wheat. In this study, we cloned a CAT gene PsCAT1 from Puccinia striiformis f. sp. tritici (Pst), which encodes a monofunctional heme-containing catalase. PsCAT1 exhibited a high degree of tolerance to pH and temperature, and forms high homopolymers.Heterologous complementation assays in Saccharomyces cerevisiae reveal that the signal peptide of PsCAT1 is functional. Overexpression of PsCAT1 enhanced S. cerevisiae resistance to H2O2. Transient expression of PsCAT1 in Nicotiana benthamiana suppressed Bax-induced cell death. Knockdown of PsCAT1 using a host-induced gene silencing (HIGS) system led to the reduced virulence of Pst, which was correlated to H2O2 accumulation in HIGS plants. These results indicate that PsCAT1 acts as an important pathogenicity factor that facilitates Pst infection by scavenging host-derived H2O2.
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Affiliation(s)
- Pu Yuan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, People's Republic of China
| | - Wenhao Qian
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, People's Republic of China
| | - Lihua Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, People's Republic of China
| | - Conghui Jia
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, People's Republic of China
| | - Xiaoxuan Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, People's Republic of China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, People's Republic of China.
| | - Jie Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, People's Republic of China.
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17
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Enzyme activity and expression of catalases in response to oxidative stress in Sporothrix schenckii. Microb Pathog 2021; 161:105270. [PMID: 34793878 DOI: 10.1016/j.micpath.2021.105270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/27/2021] [Accepted: 10/25/2021] [Indexed: 10/19/2022]
Abstract
Sporothrix schenckii is a dimorphic fungus, pathogenic to humans and animals, which is usually infective in the yeast form. Reactive oxygen species (ROS) play an important role in the host's defense, damaging the pathogen's DNA, proteins, and lipids. To prevent oxidative damage, the ROS are detoxified by pathogen-derived antioxidant enzymes such as catalases (CATs). In this work, we analyzed the activity and expression level of three S. schenckii genes, designated as CAT1, CAT2, and CAT3, that putatively encoded for three isoforms of monofunctional CAT with a predicted molecular weight of 57.6, 56.2, and 81.4 kDa, respectively. Our results demonstrate that oxidative stress induced by exogenous H2O2 leads to an altered lipid peroxidation, modifying CAT activity and the expression levels of the CAT genes, being CAT1 and CAT3 the genes with the highest expression in response to the oxidizing agent. These results show that CAT isoforms in S. schenckii can be regulated in response to oxidative stress and might help to control ROS homeostasis in the fungus-host interaction.
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18
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Traynor AM, Owens RA, Coughlin CM, Holton MC, Jones GW, Calera JA, Doyle S. At the metal-metabolite interface in Aspergillus fumigatus: towards untangling the intersecting roles of zinc and gliotoxin. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34738889 PMCID: PMC8743625 DOI: 10.1099/mic.0.001106] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cryptic links between apparently unrelated metabolic systems represent potential new drug targets in fungi. Evidence of such a link between zinc and gliotoxin (GT) biosynthesis in Aspergillus fumigatus is emerging. Expression of some genes of the GT biosynthetic gene cluster gli is influenced by the zinc-dependent transcription activator ZafA, zinc may relieve GT-mediated fungal growth inhibition and, surprisingly, GT biosynthesis is influenced by zinc availability. In A. fumigatus, dithiol gliotoxin (DTG), which has zinc-chelating properties, is converted to either GT or bis-dethiobis(methylthio)gliotoxin (BmGT) by oxidoreductase GliT and methyltransferase GtmA, respectively. A double deletion mutant lacking both GliT and GtmA was previously observed to be hypersensitive to exogenous GT exposure. Here we show that compared to wild-type exposure, exogenous GT and the zinc chelator N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) inhibit A. fumigatus ΔgliTΔgtmA growth, specifically under zinc-limiting conditions, which can be reversed by zinc addition. While GT biosynthesis is evident in zinc-depleted medium, addition of zinc (1 µM) suppressed GT and activated BmGT production. In addition, secretion of the unferrated siderophore, triacetylfusarinine C (TAFC), was evident by A. fumigatus wild-type (at >5 µM zinc) and ΔgtmA (at >1 µM zinc) in a low-iron medium. TAFC secretion suggests that differential zinc-sensing between both strains may influence fungal Fe3+ requirement. Label-free quantitative proteomic analysis of both strains under equivalent differential zinc conditions revealed protein abundance alterations in accordance with altered metabolomic observations, in addition to increased GliT abundance in ΔgtmA at 5 µM zinc, compared to wild-type, supporting a zinc-sensing deficiency in the mutant strain. The relative abundance of a range of oxidoreductase- and secondary metabolism-related enzymes was also evident in a zinc- and strain-dependent manner. Overall, we elaborate new linkages between zinc availability, natural product biosynthesis and oxidative stress homeostasis in A. fumigatus.
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Affiliation(s)
- Aimee M Traynor
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Rebecca A Owens
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Claudia M Coughlin
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Maeve C Holton
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Gary W Jones
- Centre for Biomedical Science Research, School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, UK
| | - José A Calera
- Instituto de Biología Funcional y Genómica (IBFG-CSIC), Universidad de Salamanca, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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The OxrA Protein of Aspergillus fumigatus Is Required for the Oxidative Stress Response and Fungal Pathogenesis. Appl Environ Microbiol 2021; 87:e0112021. [PMID: 34524893 DOI: 10.1128/aem.01120-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An efficient reactive oxygen species (ROS) detoxification system is vital for the survival of the pathogenic fungus Aspergillus fumigatus within the host high-ROS environment of the host. Therefore, identifying and targeting factors essential for oxidative stress response is one approach to developing novel treatments for fungal infections. The oxidation resistance 1 (Oxr1) protein is essential for protection against oxidative stress in mammals, but its functions in pathogenic fungi remain unknown. The present study aimed to characterize the role of an Oxr1 homolog in A. fumigatus. The results indicated that the OxrA protein plays an important role in oxidative stress resistance by regulating the catalase function in A. fumigatus, and overexpression of catalase can rescue the phenotype associated with OxrA deficiency. Importantly, the deficiency of oxrA decreased the virulence of A. fumigatus and altered the host immune response. Using the Aspergillus-induced lung infection model, we demonstrated that the ΔoxrA mutant strain induced less tissue damage along with decreased levels of lactate dehydrogenase (LDH) and albumin release. Additionally, the ΔoxrA mutant caused inflammation at a lower degree, along with a markedly reduced influx of neutrophils to the lungs and a decreased secretion of cytokine usually associated with recruitment of neutrophils in mice. These results characterize the role of OxrA in A. fumigatus as a core regulator of oxidative stress resistance and fungal pathogenesis. IMPORTANCE Knowledge of ROS detoxification in fungal pathogens is useful in the design of new antifungal drugs and could aid in the study of oxidative stress resistance mechanisms. In this study, we demonstrate that OxrA protein localizes to the mitochondria and functions to protect against oxidative damage. We demonstrate that OxrA contributes to oxidative stress resistance by regulating catalase function, and overexpression of catalase (CatA or CatB) can rescue the phenotype that is associated with OxrA deficiency. Remarkably, a loss of OxrA attenuated the fungal virulence in a mouse model of invasive pulmonary aspergillosis and altered the host immune response. Therefore, our finding indicates that inhibition of OxrA might be an effective approach for alleviating A. fumigatus infection. The present study is, to the best of our knowledge, a pioneer in reporting the vital role of Oxr1 protein in pathogenic fungi.
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Functional Analysis of Keto-Acid Reductoisomerase ILVC in the Entomopathogenic Fungus Metarhizium robertsii. J Fungi (Basel) 2021; 7:jof7090737. [PMID: 34575775 PMCID: PMC8471054 DOI: 10.3390/jof7090737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 11/28/2022] Open
Abstract
Ketol-acid reductoisomerase (ILVC) is the second enzyme in the branched-chain amino acid (BCAA) biosynthesis, which regulates many physiological activities in a variety of organisms from bacteria to fungi and plants. In this work, function mechanisms of ILVC in Metarhizium robertsii Metchnikoff (Hypocreales: Clavicipitaceae) were explored with site-directed mutagenesis, reductase activity assays and transcriptomics analysis. The reductase activity assays showed that ILVC from phytopathogenic fungi exhibited significantly higher activities than those from entomopathogenic fungi but lower than those from yeast. Site-directed mutagenesis and enzymatic activities of MrILVC with different active-site mutants (Arg-113, Ser-118, Asp-152, Asp-260, and Glu-264) confirmed that active sites of MrILVC are conserved with plant and bacterial ILVCs. Deleting MrilvC causes the complete failures of vegetative growth and conidial germination, feeding with branched-chain amino acids (BCAAs) recovers the fungal growth but not conidial germination, while both characteristics are restored when supplemented with yeast extract. Compared to ΔMrilvC cultured in czapek agar (CZA), plenty of genes involved in the biosynthesis of antibiotics and amino acids were up- or down-regulated in the wild type or ΔMrilvC feeding with either BCAAs or yeast extract. Further analysis showed some genes, such as catalase A, participate in mycelial growth and conidial germination was down-regulated in ΔMrilvC from CZA, revealing that MrILVC might control the fungal development by gene regulation and BCAAs or yeast extract could play partial roles of MrILVC. This study will advance our understanding of ILVC function mechanisms in fungi.
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21
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Steenwyk JL, Mead ME, de Castro PA, Valero C, Damasio A, dos Santos RAC, Labella AL, Li Y, Knowles SL, Raja HA, Oberlies NH, Zhou X, Cornely OA, Fuchs F, Koehler P, Goldman GH, Rokas A. Genomic and Phenotypic Analysis of COVID-19-Associated Pulmonary Aspergillosis Isolates of Aspergillus fumigatus. Microbiol Spectr 2021; 9:e0001021. [PMID: 34106569 PMCID: PMC8552514 DOI: 10.1128/spectrum.00010-21] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
The ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19), first described in Wuhan, China. A subset of COVID-19 patients has been reported to have acquired secondary infections by microbial pathogens, such as opportunistic fungal pathogens from the genus Aspergillus. To gain insight into COVID-19-associated pulmonary aspergillosis (CAPA), we analyzed the genomes and characterized the phenotypic profiles of four CAPA isolates of Aspergillus fumigatus obtained from patients treated in the area of North Rhine-Westphalia, Germany. By examining the mutational spectrum of single nucleotide polymorphisms, insertion-deletion polymorphisms, and copy number variants among 206 genes known to modulate A. fumigatus virulence, we found that CAPA isolate genomes do not exhibit significant differences from the genome of the Af293 reference strain. By examining a number of factors, including virulence in an invertebrate moth model, growth in the presence of osmotic, cell wall, and oxidative stressors, secondary metabolite biosynthesis, and the MIC of antifungal drugs, we found that CAPA isolates were generally, but not always, similar to A. fumigatus reference strains Af293 and CEA17. Notably, CAPA isolate D had more putative loss-of-function mutations in genes known to increase virulence when deleted. Moreover, CAPA isolate D was significantly more virulent than the other three CAPA isolates and the A. fumigatus reference strains Af293 and CEA17, but similarly virulent to two other clinical strains of A. fumigatus. These findings expand our understanding of the genomic and phenotypic characteristics of isolates that cause CAPA. IMPORTANCE The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), has already killed millions of people. COVID-19 patient outcome can be further complicated by secondary infections, such as COVID-19-associated pulmonary aspergillosis (CAPA). CAPA is caused by Aspergillus fungal pathogens, but there is little information about the genomic and phenotypic characteristics of CAPA isolates. We conducted genome sequencing and extensive phenotyping of four CAPA isolates of Aspergillus fumigatus from Germany. We found that CAPA isolates were often, but not always, similar to other reference strains of A. fumigatus across 206 genetic determinants of infection-relevant phenotypes, including virulence. For example, CAPA isolate D was more virulent than other CAPA isolates and reference strains in an invertebrate model of fungal disease, but similarly virulent to two other clinical strains. These results expand our understanding of COVID-19-associated pulmonary aspergillosis.
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Affiliation(s)
- Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew E. Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), Campinas-SP, Brazil
- Experimental Medicine Research Cluster (EMRC), University of Campinas (UNICAMP), Campinas-SP, Brazil
| | - Renato A. C. dos Santos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Abigail L. Labella
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Yuanning Li
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Xiaofan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Oliver A. Cornely
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- ZKS Köln, Clinical Trials Centre Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn‐Cologne, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Frieder Fuchs
- Faculty of Medicine, Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany
| | - Philipp Koehler
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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22
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The Peroxiredoxin Asp f3 Acts as Redox Sensor in Aspergillus fumigatus. Genes (Basel) 2021; 12:genes12050668. [PMID: 33946853 PMCID: PMC8145481 DOI: 10.3390/genes12050668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022] Open
Abstract
The human pathogenic fungus Aspergillus fumigatus is readily eradicated by the innate immunity of immunocompetent human hosts, but can cause severe infections, such as invasive aspergillosis (IA), in immunocompromised individuals. During infection, the fungal redox homeostasis can be challenged by reactive oxygen species (ROS), either derived from the oxidative burst of innate immune cells or the action of antifungal drugs. The peroxiredoxin Asp f3 was found to be essential to cause IA in mice, but how Asp f3 integrates with fungal redox homeostasis remains unknown. Here, we show that in vivo, Asp f3 acts as a sensor for ROS. While global transcription in fungal hyphae under minimal growth conditions was fully independent of Asp f3, a robust induction of the oxidative stress response required the presence of the peroxiredoxin. Hyphae devoid of Asp f3 failed to activate several redox active genes, like members of the gliotoxin biosynthesis gene cluster and integral members of the Afyap1 regulon, the central activator of the ROS defense machinery in fungi. Upon deletion of the asp f3 gene Afyap1 displayed significantly reduced nuclear localization during ROS exposure, indicating that Asp f3 can act as an intracellular redox sensor for several target proteins.
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Wang JJ, Yin YP, Song JZ, Hu SJ, Cheng W, Qiu L. A p53-like transcription factor, BbTFO1, contributes to virulence and oxidative and thermal stress tolerances in the insect pathogenic fungus, Beauveria bassiana. PLoS One 2021; 16:e0249350. [PMID: 33788872 PMCID: PMC8011754 DOI: 10.1371/journal.pone.0249350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/16/2021] [Indexed: 11/19/2022] Open
Abstract
The p53-like transcription factor (TF) NDT80 plays a vital role in the regulation of pathogenic mechanisms and meiosis in certain fungi. However, the effects of NDT80 on entomopathogenic fungi are still unknown. In this paper, the NDT80 orthologue BbTFO1 was examined in Beauveria bassiana, a filamentous entomopathogenic fungus, to explore the role of an NDT80-like protein for fungal pest control potential. Disruption of BbTFO1 resulted in impaired resistance to oxidative stress (OS) in a growth assay under OS and a 50% minimum inhibitory concentration experiment. Intriguingly, the oxidation resistance changes were accompanied by transcriptional repression of the two key antioxidant enzyme genes cat2 and cat5. ΔBbTFO1 also displayed defective conidial germination, virulence and heat resistance. The specific supplementation of BbTFO1 reversed these phenotypic changes. As revealed by this work, BbTFO1 can affect the transcription of catalase genes and play vital roles in the maintenance of phenotypes associated with the biological control ability of B. bassiana.
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Affiliation(s)
- Juan-Juan Wang
- School of Biological Science and Technology, University of Jinan, Jinan, China
- * E-mail: (JJW); (LQ)
| | - Ya-Ping Yin
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Ji-Zheng Song
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
- Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Shun-Juan Hu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Wen Cheng
- Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Lei Qiu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
- * E-mail: (JJW); (LQ)
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F. Q. Smith D, Casadevall A. Fungal immunity and pathogenesis in mammals versus the invertebrate model organism Galleria mellonella. Pathog Dis 2021; 79:ftab013. [PMID: 33544836 PMCID: PMC7981337 DOI: 10.1093/femspd/ftab013] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
In recent decades, Galleria mellonella (Lepidoptera: Pyralidae) have emerged as a model system to explore experimental aspects of fungal pathogenesis. The benefits of the G. mellonella model include being faster, cheaper, higher throughput and easier compared with vertebrate models. Additionally, as invertebrates, their use is subject to fewer ethical and regulatory issues. However, for G. mellonella models to provide meaningful insight into fungal pathogenesis, the G. mellonella-fungal interactions must be comparable to mammalian-fungal interactions. Indeed, as discussed in the review, studies suggest that G. mellonella and mammalian immune systems share many similarities, and fungal virulence factors show conserved functions in both hosts. While the moth model has opened novel research areas, many comparisons are superficial and leave large gaps of knowledge that need to be addressed concerning specific mechanisms underlying G. mellonella-fungal interactions. Closing these gaps in understanding will strengthen G. mellonella as a model for fungal virulence in the upcoming years. In this review, we provide comprehensive comparisons between fungal pathogenesis in mammals and G. mellonella from immunological and virulence perspectives. When information on an antifungal immune component is unknown in G. mellonella, we include findings from other well-studied Lepidoptera. We hope that by outlining this information available in related species, we highlight areas of needed research and provide a framework for understanding G. mellonella immunity and fungal interactions.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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Aspergillus fumigatus Strain-Specific Conidia Lung Persistence Causes an Allergic Broncho-Pulmonary Aspergillosis-Like Disease Phenotype. mSphere 2021; 6:6/1/e01250-20. [PMID: 33597172 PMCID: PMC8544898 DOI: 10.1128/msphere.01250-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aspergillus fumigatus is a filamentous fungus which can cause multiple diseases in humans. Allergic broncho-pulmonary aspergillosis (ABPA) is a disease diagnosed primarily in cystic fibrosis patients caused by a severe allergic response often to long-term A. fumigatus colonization in the lungs. Mice develop an allergic response to repeated inhalation of A. fumigatus spores; however, no strains have been identified that can survive long-term in the mouse lung and cause ABPA-like disease. We characterized A. fumigatus strain W72310, which was isolated from the expectorated sputum of an ABPA patient, by whole-genome sequencing and in vitro and in vivo viability assays in comparison to a common reference strain, CEA10. W72310 was resistant to leukocyte-mediated killing and persisted in the mouse lung longer than CEA10, a phenotype that correlated with greater resistance to oxidative stressors, hydrogen peroxide, and menadione, in vitro. In animals both sensitized and challenged with W72310, conidia, but not hyphae, were viable in the lungs for up to 21 days in association with eosinophilic airway inflammation, airway leakage, serum IgE, and mucus production. W72310-sensitized mice that were recall challenged with conidia had increased inflammation, Th1 and Th2 cytokines, and airway leakage compared to controls. Collectively, our studies demonstrate that a unique strain of A. fumigatus resistant to leukocyte killing can persist in the mouse lung in conidial form and elicit features of ABPA-like disease. IMPORTANCE Allergic broncho-pulmonary aspergillosis (ABPA) patients often present with long-term colonization of Aspergillus fumigatus. Current understanding of ABPA pathogenesis has been complicated by a lack of long-term in vivo fungal persistence models. We have identified a clinical isolate of A. fumigatus, W72310, which persists in the murine lung and causes an ABPA-like disease phenotype. Surprisingly, while viable, W72310 showed little to no growth beyond the conidial stage in the lung. This indicates that it is possible that A. fumigatus can cause allergic disease in the lung without any significant hyphal growth. The identification of this strain of A. fumigatus can be used not only to better understand disease pathogenesis of ABPA and potential antifungal treatments but also to identify features of fungal strains that drive long-term fungal persistence in the lung. Consequently, these observations are a step toward helping resolve the long-standing question of when to utilize antifungal therapies in patients with ABPA and fungal allergic-type diseases.
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Huang Z, Lu J, Liu R, Wang P, Hu Y, Fang A, Yang Y, Qing L, Bi C, Yu Y. SsCat2 encodes a catalase that is critical for the antioxidant response, QoI fungicide sensitivity, and pathogenicity of Sclerotinia sclerotiorum. Fungal Genet Biol 2021; 149:103530. [PMID: 33561548 DOI: 10.1016/j.fgb.2021.103530] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 10/22/2022]
Abstract
Sclerotinia sclerotiorum is a destructive necrotrophic fungal pathogen with worldwide distribution. The metabolism of reactive oxygen species (ROS) is critical for the development and infection process of this economically important pathogen. Hydrogen peroxide (H2O2) is converted into water and dioxygen by catalases, which are major ROS scavengers in cells. Several genes have been predicted to encode the catalases of S. sclerotiorum, but the critical ones that function in the ROS stress response are still unknown. In this research, a catalase gene called SsCat2 was found to contribute to the predominant catalase activity at the stages of hyphae growth and sclerotial development. SsCat2 transcripts were induced under oxidative stress, and the target deletion of SsCat2 led to significant sensitivity to H2O2, suggesting that SsCat2 is critical in dealing with the oxidative stress. SsCat2-deletion strains were sensitive to hyperosmotic stresses and cell membrane-perturbing agents, suggesting impairment in cell integrity due to the inactivation of SsCat2. The expression of the alternative oxidase-encoding gene was upregulated in the SsCat2-deletion strains, which showed decreased sensitivity to QoI fungicides. SsCat2-deletion strains showed impaired virulence in different hosts, and more H2O2 accumulation was detected during the infect processes. In summary, these results indicate that SsCat2 encodes a catalase that is related to the oxidative stress response, QoI fungicide sensitivity, and pathogenicity of S. sclerotiorum.
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Affiliation(s)
- Zhiqiang Huang
- College of Plant Protection, Southwest University, Chongqing, China
| | - Jingjing Lu
- College of Plant Protection, Southwest University, Chongqing, China
| | - Ruiwen Liu
- College of Plant Protection, Southwest University, Chongqing, China
| | - Pei Wang
- College of Plant Protection, Southwest University, Chongqing, China
| | - Yawen Hu
- College of Plant Protection, Southwest University, Chongqing, China
| | - Anfei Fang
- College of Plant Protection, Southwest University, Chongqing, China
| | - Yuheng Yang
- College of Plant Protection, Southwest University, Chongqing, China
| | - Ling Qing
- College of Plant Protection, Southwest University, Chongqing, China
| | - Chaowei Bi
- College of Plant Protection, Southwest University, Chongqing, China
| | - Yang Yu
- College of Plant Protection, Southwest University, Chongqing, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing, China.
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Chen M, Zhong G, Wang S, Zhu J, Tang L, Li L. tpo3 and dur3, Aspergillus fumigatus Plasma Membrane Regulators of Polyamines, Regulate Polyamine Homeostasis and Susceptibility to Itraconazole. Front Microbiol 2021; 11:563139. [PMID: 33391196 PMCID: PMC7772357 DOI: 10.3389/fmicb.2020.563139] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is a well-known opportunistic pathogen that causes invasive aspergillosis (IA) infections, which have high mortality rates in immunosuppressed individuals. Long-term antifungal drug azole use in clinical treatment and agriculture results in loss of efficacy or drug resistance. Drug resistance is related to cellular metabolites and the corresponding gene transcription. In this study, through untargeted metabolomics and transcriptomics under itraconazole (ITC) treatment, we identified two plasma membrane-localized polyamine regulators tpo3 and dur3, which were important for polyamine homeostasis and susceptibility to ITC in A. fumigatus. In the absence of tpo3 and/or dur3, the levels of cytoplasmic polyamines had a moderate increase, which enhanced the tolerance of A. fumigatus to ITC. In comparison, overexpression of tpo3 or dur3 induced a drastic increase in polyamines, which increased the sensitivity of A. fumigatus to ITC. Further analysis revealed that polyamines concentration-dependently affected the susceptibility of A. fumigatus to ITC by scavenging reactive oxygen species (ROS) at a moderate concentration and promoting the production of ROS at a high concentration rather than regulating drug transport. Moreover, inhibition of polyamine biosynthesis reduced the intracellular polyamine content, resulted in accumulation of ROS and enhanced the antifungal activity of ITC. Interestingly, A. fumigatus produces much lower levels of ROS under voriconazole (VOC) treatment than under ITC-treatment. Accordingly, our study established the link among the polyamine regulators tpo3 and dur3, polyamine homeostasis, ROS content, and ITC susceptibility in A. fumigatus.
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Affiliation(s)
- Mingcong Chen
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Guowei Zhong
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Sha Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou Central Hospital, Huzhou University, Huzhou, China
| | - Jun Zhu
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Tang
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Li
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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Takahashi-Nakaguchi A, Shishido E, Yahara M, Urayama SI, Ninomiya A, Chiba Y, Sakai K, Hagiwara D, Chibana H, Moriyama H, Gonoi T. Phenotypic and Molecular Biological Analysis of Polymycovirus AfuPmV-1M From Aspergillus fumigatus: Reduced Fungal Virulence in a Mouse Infection Model. Front Microbiol 2020; 11:607795. [PMID: 33424809 PMCID: PMC7794001 DOI: 10.3389/fmicb.2020.607795] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/24/2020] [Indexed: 11/30/2022] Open
Abstract
The filamentous fungal pathogen Aspergillus fumigatus is one of the most common causal agents of invasive fungal infection in humans; the infection is associated with an alarmingly high mortality rate. In this study, we investigated whether a mycovirus, named AfuPmV-1M, can reduce the virulence of A. fumigatus in a mouse infection model. AfuPmV-1M has high sequence similarity to AfuPmV-1, one of the polymycovirus that is a capsidless four-segment double-stranded RNA (dsRNA) virus, previously isolated from the genome reference strain of A. fumigatus, Af293. However, we found the isolate had an additional fifth dsRNA segment, referred to as open reading frame 5 (ORF5), which has not been reported in AfuPmV-1. We then established isogenic lines of virus-infected and virus-free A. fumigatus strains. Mycovirus infection had apparent influences on fungal phenotypes, with the virus-infected strain producing a reduced mycelial mass and reduced conidial number in comparison with these features of the virus-free strain. Also, resting conidia of the infected strain showed reduced adherence to pulmonary epithelial cells and reduced tolerance to macrophage phagocytosis. In an immunosuppressed mouse infection model, the virus-infected strain showed reduced mortality in comparison with mortality due to the virus-free strain. RNA sequencing and high-performance liquid chromatography (HPLC) analysis showed that the virus suppressed the expression of genes for gliotoxin synthesis and its production at the mycelial stage. Conversely, the virus enhanced gene expression and biosynthesis of fumagillin. Viral RNA expression was enhanced during conidial maturation, conidial germination, and the mycelial stage. We presume that the RNA or translation products of the virus affected fungal phenotypes, including spore formation and toxin synthesis. To identify the mycovirus genes responsible for attenuation of fungal virulence, each viral ORF was ectopically expressed in the virus-free KU strain. We found that the expression of ORF2 and ORF5 reduced fungal virulence in the mouse model. In addition, ORF3 affected the stress tolerance of host A. fumigatus in culture. We hypothesize that the respective viral genes work cooperatively to suppress the pathogenicity of the fungal host.
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Affiliation(s)
| | - Erika Shishido
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Misa Yahara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Syun-Ichi Urayama
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Japan
| | - Akihiro Ninomiya
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yuto Chiba
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Kanae Sakai
- Medical Mycology Research Center, Chiba University, Chiba, Japan.,Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Daisuke Hagiwara
- Medical Mycology Research Center, Chiba University, Chiba, Japan.,Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Japan
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Hiromitsu Moriyama
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Tohru Gonoi
- Medical Mycology Research Center, Chiba University, Chiba, Japan
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Igbalajobi O, Gao J, Fischer R. The HOG Pathway Plays Different Roles in Conidia and Hyphae During Virulence of Alternaria alternata. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1405-1410. [PMID: 33104446 DOI: 10.1094/mpmi-06-20-0165-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The black mold Alternaria alternata causes dramatic losses in agriculture due to postharvest colonization and mycotoxin formation and is a weak pathogen on living plants. Fungal signaling processes are crucial for successful colonization of a host plant. Because the mitogen-activated protein kinase HogA is important for the expression of stress-associated genes, we tested a ∆hogA-deletion strain for pathogenicity. When conidia were used as inoculum, the ∆hogA-deletion strain was largely impaired in colonizing tomato and apple. In comparison, hyphae as inoculum colonized the fruit very well. Hence, HogA appears to be important only in the initial stages of plant colonization. A similar difference between conidial inoculum and hyphal inoculum was observed on artificial medium in the presence of different stress agents. Whereas wild-type conidia adapted well to different stresses, the ∆hogA-deletion strain failed to grow under the same conditions. With hyphae as inoculum, the wild type and the ∆hogA-deletion strain grew in a very similar way. At the molecular level, we observed upregulation of several catalase (catA, -B, and -D) and superoxide dismutase (sodA, -B, and -E) genes in germlings but not in hyphae after exposure to 4 mM hydrogen peroxide. The upregulation required the high osmolarity glycerol (HOG) pathway. In contrast, in mycelia, catD, sodA, sodB, and sodE were upregulated upon stress in the absence of HogA. Several other stress-related genes behaved in a similar way.
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Affiliation(s)
- Olumuyiwa Igbalajobi
- Karlsruhe Institute of Technology (KIT)-South Campus, Institute of Applied Biosciences, Department of Microbiology, Fritz-Haber-Weg 4,D-76131 Karlsruhe, Germany
| | - Jia Gao
- Karlsruhe Institute of Technology (KIT)-South Campus, Institute of Applied Biosciences, Department of Microbiology, Fritz-Haber-Weg 4,D-76131 Karlsruhe, Germany
| | - Reinhard Fischer
- Karlsruhe Institute of Technology (KIT)-South Campus, Institute of Applied Biosciences, Department of Microbiology, Fritz-Haber-Weg 4,D-76131 Karlsruhe, Germany
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Pennerman KK, Yin G, Glenn AE, Bennett JW. Identifying candidate Aspergillus pathogenicity factors by annotation frequency. BMC Microbiol 2020; 20:342. [PMID: 33176679 PMCID: PMC7661267 DOI: 10.1186/s12866-020-02031-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/02/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Members of the genus Aspergillus display a variety of lifestyles, ranging from saprobic to pathogenic on plants and/or animals. Increased genome sequencing of economically important members of the genus permits effective use of "-omics" comparisons between closely related species and strains to identify candidate genes that may contribute to phenotypes of interest, especially relating to pathogenicity. Protein-coding genes were predicted from 216 genomes of 12 Aspergillus species, and the frequencies of various structural aspects (exon count and length, intron count and length, GC content, and codon usage) and functional annotations (InterPro, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes terms) were compared. RESULTS Using principal component analyses, the three sets of functional annotations for each strain were clustered by species. The species clusters appeared to separate by pathogenicity on plants along the first dimensions, which accounted for over 20% of the variance. More annotations for genes encoding pectinases and secondary metabolite biosynthetic enzymes were assigned to phytopathogenic strains from species such as Aspergillus flavus. In contrast, Aspergillus fumigatus strains, which are pathogenic to animals but not plants, were assigned relatively more terms related to phosphate transferases, and carbohydrate and amino-sugar metabolism. Analyses of publicly available RNA-Seq data indicated that one A. fumigatus protein among 17 amino-sugar processing candidates, a hexokinase, was up-regulated during co-culturing with human immune system cells. CONCLUSION Genes encoding hexokinases and other proteins of interest may be subject to future manipulations to further refine understanding of Aspergillus pathogenicity factors.
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Affiliation(s)
- Kayla K Pennerman
- United States Department of Agriculture, Toxicology and Mycotoxin Research Unit, Athens, GA, 30605, USA.
| | - Guohua Yin
- Department of Plant Biology, Rutgers University, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Anthony E Glenn
- United States Department of Agriculture, Toxicology and Mycotoxin Research Unit, Athens, GA, 30605, USA
| | - Joan W Bennett
- Department of Plant Biology, Rutgers University, The State University of New Jersey, New Brunswick, NJ, 08901, USA
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Compare Catalase Activity Between Aspergillus flavus and A. fumigatus, Isolated from Clinical and Environmental Specimens. Jundishapur J Microbiol 2020. [DOI: 10.5812/jjm.103634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Catalase enzyme is a potential virulence factor for Aspergillus species. Objectives: This study aimed to evaluate the catalase activity in conidium and mycelium of Aspergillus flavus and A. fumigatus isolated from environmental and clinical samples. Methods: Forty Aspergillus species (20 A. fumigatus and 20 A. flavus) were evaluated. Species were identified using the macroscopic and microscopic criteria of the isolates on culture media and the PCR-RFLP method, using the MwoI enzyme. The activity of the enzyme was evaluated using the Amplex red catalase assay kit. The Shapiro Wilk, Kolmogorov-Smirnov, Mann-Whitney, and Wilcoxon Signed Rank tests were used to analyze the data. Results: The mean conidial and mycelial catalase activities in A. flavus clinical and environmental isolates were 58.10, 57.80 mU/mL, and 1328.30, 531.60 mU/mL, respectively. In A. fumigatus clinical and environmental isolates, the activities were 61.10 and 61.40 mU/mL, and 1248.90 and 722.90 mU/mL, respectively. A significant difference was found between conidial and mycelial catalase activity in Aspergillus species (P = 0.01). The mycelial catalase activity of Aspergillus species isolated from clinical samples was higher than the environmental ones (A. flavus P = 0.01 and A. fumigatus P = 0.04). Conclusions: The mycelial catalase activity was higher than conidia. Clinical isolates of A. flavus had similar mycelium activity to A. fumigatus. By using the information provided in the present study, the severity of aspergillosis can be predicted, which paves the way for identifying new antifungal agents.
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Ernesto Juniors PT, Valeria CL, Santiago PO, Mario RM, Gabriela SJ. Tolerance to oxidative stress caused by copper (Cu) in Trichoderma asperellum To. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Lin CJ, Hou YH, Chen YL. The histone acetyltransferase GcnE regulates conidiation and biofilm formation in Aspergillus fumigatus. Med Mycol 2020; 58:248-259. [PMID: 31100153 DOI: 10.1093/mmy/myz043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/22/2019] [Accepted: 04/11/2019] [Indexed: 01/03/2023] Open
Abstract
Histone modifications play a crucial role in eukaryotic gene regulation. The Spt-Ada-Gcn5-acetyltransferase (SAGA) complex controls histone acetylation, with Gcn5 (GcnE) acting as the acetyltransferase. In the Aspergillus species, GcnE has been shown to regulate asexual development and secondary metabolism. Apart from this, GcnE is required for pathogenicity in plant fungal pathogen A. flavus; however, the role of GcnE in the pathogenicity of human pathogenic fungus A. fumigatus is unknown. In this study, we uncovered the key roles of GcnE in A. fumigatus conidiation, stress responses, and biofilm formation. We observed that deletion of gcnE resulted in aberrant conidiation in which conidiophores displayed abnormal phialide formation. In addition, the ΔgcnE mutant grew slightly faster under limited nitrogen sources (1 mM of ammonium or nitrate) compared to the wild type. The ΔgcnE mutant exhibited increased susceptibility to cell wall-perturbing agents, H2O2 and menadione but enhanced tolerance to LiCl. Furthermore, we showed that GcnE is involved in biofilm formation, and overexpression of adherence-related genes such as somA or uge3 partially rescued biofilm formation defects in the ΔgcnE mutant background. Interestingly, GcnE was not required for virulence in a neutropenic murine model of invasive aspergillosis. These results suggest that GcnE is critical for conidiation and biofilm formation but not virulence in A. fumigatus.
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Affiliation(s)
- Chi-Jan Lin
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
| | - Yi-Hsuan Hou
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
| | - Ying-Lien Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
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Melo AM, Poester VR, Trapaga M, Nogueira CW, Zeni G, Martinez M, Sass G, Stevens DA, Xavier MO. Diphenyl diselenide and its interaction with antifungals against Aspergillus spp. Med Mycol 2020; 59:myaa072. [PMID: 32844203 DOI: 10.1093/mmy/myaa072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/16/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023] Open
Abstract
Given the few antifungal classes available to treat aspergillosis, this study aimed to evaluate the in vitro antifungal activity of diphenyl diselenide (PhSe)2 alone and in combination with classical antifungals against Aspergillus spp., and its in vivo activity in a systemic experimental aspergillosis model. We performed in vitro broth microdilution assay of (PhSe)2 against 32 Aspergillus isolates; and a checkboard assay to test the interaction of this compound with itraconazole (ITC), voriconazole (VRC), amphotericin B (AMB), and caspofungin (CAS), against nine Aspergillus isolates. An experimental model of invasive aspergillosis in mice was studied, and survival curves were compared between an untreated group and groups treated with 100 mg/kg ITC, or (PhSe)2 in different dosages (10 mg/kg, 50 mg/kg and 100 mg/kg). All Aspergillus non-fumigatus and 50% of A. fumigatus were inhibited by (PhSe)2 in concentrations ≤ 64 µg/ml, with significant differences in MICs between the sections. Synergism or additive effect in the in vitro (PhSe)2 interaction with VRC and CAS was observed against the majority of isolates, and with ITC against the non-fumigatus strains. In addition to the inhibitory interaction, (PhSe)2 was able to add a fungicidal effect to CAS. Survival curves from the systemic experimental aspergillosis model demonstrated that the inoculum caused an acute and lethal infection in mice, and no treatment applied significantly prolonged survival over that of the control group. The results highlight the promising activity of (PhSe)2 against Aspergillus species, but more in vivo studies are needed to determine its potential applicability in aspergillosis treatment. LAY SUMMARY The activity of diphenyl diselenide (PhSe)2 alone and in combination with itraconazole, voriconazole, and caspofungin, is described against three of the most pathogenic Aspergillus sections. (PhSe)2 may prove useful in therapy of infection in future; further study is required.
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Affiliation(s)
- Aryse Martins Melo
- Microbiology and Parasitology Post-graduation program, Institute of Biology, Federal University of Pelotas, Pelotas, RS, Brazil
- Department of Infectious Diseases/Reference Unit for Parasitic and Fungal Infections, National Institute of Health, Dr. Ricardo Jorge, Lisbon, Portugal
- Mycology Laboratory, College of Medicine, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - Vanice Rodrigues Poester
- Mycology Laboratory, College of Medicine, Federal University of Rio Grande, Rio Grande, RS, Brazil
- Health Science Post-graduation program, College of Medicine, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - Mariana Trapaga
- Mycology Laboratory, College of Medicine, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - Cristina Wayne Nogueira
- Biological Sciences Post-graduation program, Department of Biochemistry and Molecular Biology, Center for Natural and Exact Sciences, Federal University of Santa Maria. RS, Brazil
| | - Gilson Zeni
- Biological Sciences Post-graduation program, Department of Biochemistry and Molecular Biology, Center for Natural and Exact Sciences, Federal University of Santa Maria. RS, Brazil
| | - Marife Martinez
- California Institute for Medical Research, San Jose, California, USA
| | - Gabriele Sass
- California Institute for Medical Research, San Jose, California, USA
| | - David A Stevens
- California Institute for Medical Research, San Jose, California, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University Medical School, Stanford, California, USA
| | - Melissa Orzechowski Xavier
- Microbiology and Parasitology Post-graduation program, Institute of Biology, Federal University of Pelotas, Pelotas, RS, Brazil
- Mycology Laboratory, College of Medicine, Federal University of Rio Grande, Rio Grande, RS, Brazil
- Health Science Post-graduation program, College of Medicine, Federal University of Rio Grande, Rio Grande, RS, Brazil
- California Institute for Medical Research, San Jose, California, USA
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Binder J, Shadkchan Y, Osherov N, Krappmann S. The Essential Thioredoxin Reductase of the Human Pathogenic Mold Aspergillus fumigatus Is a Promising Antifungal Target. Front Microbiol 2020; 11:1383. [PMID: 32670238 PMCID: PMC7330004 DOI: 10.3389/fmicb.2020.01383] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
The identification of cellular targets for antifungal compounds is a cornerstone for the development of novel antimycotics, for which a significant need exists due to increasing numbers of susceptible patients, emerging pathogens, and evolving resistance. For the human pathogenic mold Aspergillus fumigatus, the causative agent of the opportunistic disease aspergillosis, only a limited number of established targets and corresponding drugs are available. Among several targets that were postulated from a variety of experimental approaches, the conserved thioredoxin reductase (TrxR) activity encoded by the trxR gene was assessed in this study. Its essentiality could be confirmed following a conditional TetOFF promoter replacement strategy. Relevance of the trxR gene product for oxidative stress resistance was revealed and, most importantly, its requirement for full virulence of A. fumigatus in two different models of infection resembling invasive aspergillosis. Our findings complement the idea of targeting the reductase component of the fungal thioredoxin system for antifungal therapy.
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Affiliation(s)
- Jasmin Binder
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Yana Shadkchan
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Nir Osherov
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Sven Krappmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Medical Immunology Campus Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Erlangen Center of Infection Research, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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36
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Zhu Z, Yang M, Bai Y, Ge F, Wang S. Antioxidant-related catalase CTA1 regulates development, aflatoxin biosynthesis, and virulence in pathogenic fungus Aspergillus flavus. Environ Microbiol 2020; 22:2792-2810. [PMID: 32250030 DOI: 10.1111/1462-2920.15011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/17/2020] [Accepted: 03/31/2020] [Indexed: 11/29/2022]
Abstract
Reactive oxygen species (ROS) induce the synthesis of a myriad of secondary metabolites, including aflatoxins. It raises significant concern as it is a potent environmental contaminant. In Aspergillus flavus., antioxidant enzymes link ROS stress response with coordinated gene regulation of aflatoxin biosynthesis. In this study, we characterized the function of a core component of the antioxidant enzyme catalase (CTA1) of A. flavus. Firstly, we verified the presence of cta1 corresponding protein (CTA1) by Western blot analysis and mass-spectrometry based analysis. Then, the functional study revealed that the growth, sporulation and sclerotia formation significantly increased, while aflatoxins production and virulence were decreased in the cta1 deletion mutant as compared with the WT and complementary strains. Furthermore, the absence of the cta1 gene resulted in a significant rise in the intracellular ROS level, which in turn added to the oxidative stress level of cells. A further quantitative proteomics investigation hinted that in vivo, CTA1 might maintain the ROS level to facilitate the aflatoxin synthesis. All in all, the pleiotropic phenotype of A. flavus CTA1 deletion mutant revealed that the antioxidant system plays a crucial role in fungal development, aflatoxins biosynthesis and virulence.
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Affiliation(s)
- Zhuo Zhu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Mingkun Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.,State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Youhuang Bai
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Feng Ge
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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Takahashi-Nakaguchi A, Shishido E, Yahara M, Urayama SI, Sakai K, Chibana H, Kamei K, Moriyama H, Gonoi T. Analysis of an Intrinsic Mycovirus Associated With Reduced Virulence of the Human Pathogenic Fungus Aspergillus fumigatus. Front Microbiol 2020; 10:3045. [PMID: 32010101 PMCID: PMC6978690 DOI: 10.3389/fmicb.2019.03045] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/17/2019] [Indexed: 11/21/2022] Open
Abstract
Aspergillus fumigatus is an airborne fungal pathogen that causes severe infections with invasive growth in immunocompromised patients. Several mycoviruses have recently been isolated from A. fumigatus strains, but there are presently no reports of mycoviral-mediated reduction or elimination of fungal pathogenicity in vertebrate models. Here, we report the biological features of a novel mycovirus, A. fumigatus chrysovirus 41362 (AfuCV41362), isolated from the hypovirulent A. fumigatus strain IFM 41362. The AfuCV41362 genome is comprised of four dsRNAs, each of which contains a single ORF (ORF1-4). ORF1 encodes a protein with sequence similarity to RNA-dependent RNA polymerases of viruses in the family Chrysoviridae, while ORF3 encodes a putative capsid protein. Viral RNAs are expressed primarily during the germination stage, and RNA-seq analysis of virus-infected A. fumigatus at the germination stage suggested that the virus suppressed expression of several pathogenicity-associated host genes, including hypoxia adaptation and nitric oxide detoxification genes. In vitro functional analysis revealed that the virus-infected strain had reduced tolerance to environmental stressors. Virus-infected A. fumigatus strain IFM 41362 had reduced virulence in vivo compared to the virus-free strain in a mouse infection model. Furthermore, introduction of the mycovirus to a natively virus-free KU A. fumigatus strain induced virus-infected phenotypes. To identify mycovirus genes responsible for the reduced virulence of A. fumigatus, each viral ORF was ectopically expressed in the virus-free KU strain. Ectopic expression of the individual ORFs only nominally reduced virulence of the host fungus in a mouse infection model. However, we found that ORF3 and ORF4 reduced tolerance to environmental stresses in in vitro analysis. Based on these results, we suggest that the AfuCV41362 mycovirus ORF3 and ORF4 reduce fungal virulence by suppressing stress tolerance together with other viral genes, rather than alone.
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Affiliation(s)
| | - Erika Shishido
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Misa Yahara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | | | - Kanae Sakai
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Katsuhiko Kamei
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | | | - Tohru Gonoi
- Medical Mycology Research Center, Chiba University, Chiba, Japan
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38
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Abstract
Aspergillus fumigatus is a saprotrophic fungus; its primary habitat is the soil. In its ecological niche, the fungus has learned how to adapt and proliferate in hostile environments. This capacity has helped the fungus to resist and survive against human host defenses and, further, to be responsible for one of the most devastating lung infections in terms of morbidity and mortality. In this review, we will provide (i) a description of the biological cycle of A. fumigatus; (ii) a historical perspective of the spectrum of aspergillus disease and the current epidemiological status of these infections; (iii) an analysis of the modes of immune response against Aspergillus in immunocompetent and immunocompromised patients; (iv) an understanding of the pathways responsible for fungal virulence and their host molecular targets, with a specific focus on the cell wall; (v) the current status of the diagnosis of different clinical syndromes; and (vi) an overview of the available antifungal armamentarium and the therapeutic strategies in the clinical context. In addition, the emergence of new concepts, such as nutritional immunity and the integration and rewiring of multiple fungal metabolic activities occurring during lung invasion, has helped us to redefine the opportunistic pathogenesis of A. fumigatus.
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Affiliation(s)
- Jean-Paul Latgé
- School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Georgios Chamilos
- School of Medicine, University of Crete, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Crete, Greece
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Abstract
Aspergilli produce conidia for reproduction or to survive hostile conditions, and they are highly effective in the distribution of conidia through the environment. In immunocompromised individuals, inhaled conidia can germinate inside the respiratory tract, which may result in invasive pulmonary aspergillosis. The management of invasive aspergillosis has become more complex, with new risk groups being identified and the emergence of antifungal resistance. Patient survival is threatened by these developments, stressing the need for alternative therapeutic strategies. As germination is crucial for infection, prevention of this process might be a feasible approach. A broader understanding of conidial germination is important to identify novel antigermination targets. In this review, we describe conidial resistance against various stresses, transition from dormant conidia to hyphal growth, the underlying molecular mechanisms involved in germination of the most common Aspergillus species, and promising antigermination targets. Germination of Aspergillus is characterized by three morphotypes: dormancy, isotropic growth, and polarized growth. Intra- and extracellular proteins play an important role in the protection against unfavorable environmental conditions. Isotropically expanding conidia remodel the cell wall, and biosynthetic machineries are needed for cellular growth. These biosynthetic machineries are also important during polarized growth, together with tip formation and the cell cycle machinery. Genes involved in isotropic and polarized growth could be effective antigermination targets. Transcriptomic and proteomic studies on specific Aspergillus morphotypes will improve our understanding of the germination process and allow discovery of novel antigermination targets and biomarkers for early diagnosis and therapy.
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40
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Zhu C, Wang Y, Hu X, Lei M, Wang M, Zeng J, Li H, Liu Z, Zhou T, Yu D. Involvement of LaeA in the regulation of conidia production and stress responses in Penicillium digitatum. J Basic Microbiol 2019; 60:82-88. [PMID: 31650621 DOI: 10.1002/jobm.201900367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 01/07/2023]
Abstract
Involvement of LaeA in various biological processes of filamentous fungi has been demonstrated. However, its role in Penicillium digitatum, the causal agent of citrus postharvest green mold, remains unclear. In this study, a ΔPdLaeA mutant was constructed using homologous recombination. The production of conidia by the ΔPdLaeA mutant was reduced by half compared with that of the wild-type strain. The sensitivity of the ΔPdLaeA mutant increased under alkaline conditions. The virulence assay revealed that PdLaeA was dispensable for the virulence of P. digitatum. Comparative transcriptome analysis revealed that the function loss of PdLaeA resulted in the reduced expression of several secondary metabolite gene clusters. In addition, expression of several key regulators of conidiation (BrlA, FlbA, FlbC, FlbD, and FluG) was also downregulated in the ΔPdLaeA mutant. In summary, the present work demonstrated that PdLaeA was involved in the regulation of SM biosynthesis, as well as the development and environmental adaptation of P. digitatum.
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Affiliation(s)
- Congyi Zhu
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Yuying Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xu Hu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Mengying Lei
- Department of Ecological Engineering, Guangdong Eco-Engineering Polytechnic, Guangzhou, China
| | - Mingshuang Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Jiwu Zeng
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Hongye Li
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Zheyu Liu
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Ting Zhou
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Dongliang Yu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
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41
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Schubert M, Xue S, Ebel F, Vaggelas A, Krylov VB, Nifantiev NE, Chudobová I, Schillberg S, Nölke G. Monoclonal Antibody AP3 Binds Galactomannan Antigens Displayed by the Pathogens Aspergillus flavus, A. fumigatus, and A. parasiticus. Front Cell Infect Microbiol 2019; 9:234. [PMID: 31380292 PMCID: PMC6646516 DOI: 10.3389/fcimb.2019.00234] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/14/2019] [Indexed: 12/16/2022] Open
Abstract
Aspergillus fumigatus and A. flavus are the fungal pathogens responsible for most cases of invasive aspergillosis (IA). Early detection of the circulating antigen galactomannan (GM) in serum allows the prompt application of effective antifungal therapy, thus improving the survival rate of IA patients. However, the use of monoclonal antibodies (mAbs) for the diagnosis of IA is often associated with false positives due to cross-reaction with bacterial polysaccharides. More specific antibodies are therefore needed. Here we describe the characterization of the Aspergillus-specific mAb AP3 (IgG1κ), including the precise identification of its corresponding antigen. The antibody was generated using A. parasiticus cell wall fragments and was shown to bind several Aspergillus species. Immunofluorescence microscopy revealed that AP3 binds a cell wall antigen, but immunoprecipitation and enzyme-linked immunosorbent assays showed that the antigen is also secreted into the culture medium. The inability of AP3 to bind the A. fumigatus galactofuranose (Galf )-deficient mutant ΔglfA confirmed that Galf residues are part of the epitope. Several lines of evidence strongly indicated that AP3 recognizes the Galf residues of O-linked glycans on Aspergillus proteins. Glycoarray analysis revealed that AP3 recognizes oligo-[β-D-Galf-1,5] sequences containing four or more residues with longer chains more efficiently. We also showed that AP3 captures GM in serum, suggesting it may be useful as a diagnostic tool for patients with IA.
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Affiliation(s)
- Max Schubert
- Department of Plant Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Sheng Xue
- Institute for Translational Medicine, College of Medicine, Qingdao University, Qingdao, China
| | - Frank Ebel
- Faculty of Veterinary Medicine, Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Annegret Vaggelas
- Faculty of Veterinary Medicine, Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Vadim B Krylov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Nikolay E Nifantiev
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ivana Chudobová
- Department of Plant Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Stefan Schillberg
- Department of Plant Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany.,Institute for Phytopathology, Justus Liebig University Giessen, Giessen, Germany
| | - Greta Nölke
- Department of Plant Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
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van der Nest MA, Steenkamp ET, Roodt D, Soal NC, Palmer M, Chan WY, Wilken PM, Duong TA, Naidoo K, Santana QC, Trollip C, De Vos L, van Wyk S, McTaggart AR, Wingfield MJ, Wingfield BD. Genomic analysis of the aggressive tree pathogen Ceratocystis albifundus. Fungal Biol 2019; 123:351-363. [PMID: 31053324 DOI: 10.1016/j.funbio.2019.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022]
Abstract
The overall goal of this study was to determine whether the genome of an important plant pathogen in Africa, Ceratocystis albifundus, is structured into subgenomic compartments, and if so, to establish how these compartments are distributed across the genome. For this purpose, the publicly available genome of C. albifundus was complemented with the genome sequences for four additional isolates using the Illumina HiSeq platform. In addition, a reference genome for one of the individuals was assembled using both PacBio and Illumina HiSeq technologies. Our results showed a high degree of synteny between the five genomes, although several regions lacked detectable long-range synteny. These regions were associated with the presence of accessory genes, lower genetic similarity, variation in read-map depth, as well as transposable elements and genes associated with host-pathogen interactions (e.g. effectors and CAZymes). Such patterns are regarded as hallmarks of accelerated evolution, particularly of accessory subgenomic compartments in fungal pathogens. Our findings thus showed that the genome of C. albifundus is made-up of core and accessory subgenomic compartments, which is an important step towards characterizing its pangenome. This study also highlights the value of comparative genomics for understanding mechanisms that may underly and influence the biology and evolution of pathogens.
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Affiliation(s)
- Magriet A van der Nest
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Danielle Roodt
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Nicole C Soal
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Marike Palmer
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Wai-Yin Chan
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - P Markus Wilken
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Tuan A Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Kershney Naidoo
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Quentin C Santana
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Conrad Trollip
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Lieschen De Vos
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Stephanie van Wyk
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Alistair R McTaggart
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Brenda D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Staerck C, Tabiasco J, Godon C, Delneste Y, Bouchara JP, Fleury MJJ. Transcriptional profiling of Scedosporium apiospermum enzymatic antioxidant gene battery unravels the involvement of thioredoxin reductases against chemical and phagocytic cells oxidative stress. Med Mycol 2019; 57:363-373. [PMID: 29889264 DOI: 10.1093/mmy/myy033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/22/2018] [Accepted: 05/01/2018] [Indexed: 12/15/2022] Open
Abstract
Scedosporium species rank the second, after Aspergillus fumigatus, among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF). Development of microorganisms in the respiratory tract depends on their capacity to evade killing by the host immune system, particularly through the oxidative response of macrophages and neutrophils, with the release of reactive oxygen species (ROS) and reactive nitrogen species (RNS). This is particularly true in the airways of CF patients which display an exacerbated inflammatory reaction. To protect themselves, pathogens have developed various enzymatic antioxidant systems implicated in ROS degradation, including superoxide dismutases, catalases, cytochrome C peroxidases, chloroperoxidases and enzymes of the glutathione and thioredoxin systems, or in RNS degradation, that is, flavohemoglobins, nitrate reductases, and nitrite reductases. Here we investigated the transcriptional regulation of the enzymatic antioxidant gene battery in 24-h-old hyphae of Scedosporium apiospermum in response to oxidative stress induced chemically or by exposure to activated phagocytic cells. We showed that 21 out of the 33 genes potentially implicated in the oxidative or nitrosative stress response were overexpressed upon exposure of the fungus to various chemical oxidants, while they were only 13 in co-cultures with macrophages or neutrophils. Among them, genes encoding two thioredoxin reductases and to a lesser extent, a peroxiredoxin and one catalase were found to be overexpressed after chemical oxidative stress as well as in co-cultures. These results suggest that thioredoxin reductases, which are known to be virulence factors in other pathogenic fungi, play a key role in pathogenesis of scedosporiosis, and may be new drug targets.
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Affiliation(s)
- Cindy Staerck
- Groupe d'Etude des Interactions Hôte-Pathogène (EA 3142), UNIV Angers, UNIV Brest, Université Bretagne-Loire, Angers, France
| | - Julie Tabiasco
- CRCINA, INSERM, Université de Nantes, Université d'Angers, Angers, France
| | - Charlotte Godon
- Groupe d'Etude des Interactions Hôte-Pathogène (EA 3142), UNIV Angers, UNIV Brest, Université Bretagne-Loire, Angers, France
| | - Yves Delneste
- CRCINA, INSERM, Université de Nantes, Université d'Angers, Angers, France.,Laboratoire d'Immunologie et Allergologie, Centre Hospitalier Universitaire d'Angers, France
| | - Jean-Philippe Bouchara
- Groupe d'Etude des Interactions Hôte-Pathogène (EA 3142), UNIV Angers, UNIV Brest, Université Bretagne-Loire, Angers, France.,Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Angers, France
| | - Maxime J J Fleury
- Groupe d'Etude des Interactions Hôte-Pathogène (EA 3142), UNIV Angers, UNIV Brest, Université Bretagne-Loire, Angers, France
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El-Katony TM, El-Dein MMN, El-Fallal AA, Ibrahim NG. Effect of the taxonomic group of fungi and type of substrate on the antioxidant activity of a solid-state fermentation system. Int Microbiol 2019; 22:203-215. [PMID: 30810984 DOI: 10.1007/s10123-018-00040-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 02/07/2023]
Abstract
The enzymatic and non-enzymatic antioxidant activities of a solid-state fermentation system (SSFS) employing six basidiomycete and four ascomycete fungi on orange peel have been evaluated. Class comparisons revealed highly significant effect of fungal group on the antioxidant activity. Peroxidase activity appeared only in the basidiomycete fungi (particularly Pleurotus columbinus, Ganoderma resinaceum, and Pleurotus floridanus) whereas catalase activity appeared in the two fungal groups in favor of the ascomycetes (particularly Paecilomyces variotii and Aspergillus fumigatus). Maximal peroxidase and minimal catalase activities were found at moderate phenolic content, with extreme phenolic levels leading to low peroxidase activity but high catalase activity. Production of the non-enzymatic antioxidants (phenolics, flavonoids, reducing power, and DPPH scavenging) was in favor of the ascomycetes, which showed great native ability to synthesize flavonoids and also to release flavonoids from orange peel. The basidiomycete fungi, which have limited native ability to produce phenolics, had high ability to consume orange peel phenolics. By contrast, the ascomycete fungi exhibited great native ability for production of phenolics and low ability to consume exogenous phenolics.
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Affiliation(s)
- Taha Mohamed El-Katony
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta City, 34517, Egypt.
| | | | - Amira Ali El-Fallal
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta City, 34517, Egypt
| | - Nourhan Gamal Ibrahim
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta City, 34517, Egypt
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Contreras G, Wang N, Schäfer H, Wink M. Oxidative stress and the presence of bacteria increase gene expression of the antimicrobial peptide aclasin, a fungal CSαβ defensin in Aspergillus clavatus. PeerJ 2019; 7:e6290. [PMID: 30828484 PMCID: PMC6394349 DOI: 10.7717/peerj.6290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/15/2018] [Indexed: 12/17/2022] Open
Abstract
Background Antimicrobial peptides (AMPs) represent a broad class of naturally occurring antimicrobial compounds. Plants, invertebrates and fungi produce various AMPs as, for example, defensins. Most of these defensins are characterised by the presence of a cysteine-stabilised α-helical and β-sheet (CSαβ) motif. The changes in gene expression of a fungal CSαβ defensin by stress conditions were investigated in Aspergillus clavatus. A. clavatus produces the CSαβ defensin Aclasin, which is encoded by the aclasin gene. Methods Aclasin expression was evaluated in submerged mycelium cultures under heat shock, osmotic stress, oxidative stress and the presence of bacteria by quantitative real-time PCR. Results Aclasin expression increased two fold under oxidative stress conditions and in the presence of viable and heat-killed Bacillus megaterium. Under heat shock and osmotic stress, aclasin expression decreased. Discussion The results suggest that oxidative stress and the presence of bacteria might regulate fungal defensin expression. Moreover, fungi might recognise microorganisms as plants and animals do.
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Affiliation(s)
- Gabriela Contreras
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Nessa Wang
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Holger Schäfer
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Michael Wink
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
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Li Z, Zhang H, Li G. Characterization of phytotoxin and secreted proteins identifies of Lasiodiplodia theobromae, causes of peach gummosis. Fungal Biol 2019; 123:51-58. [PMID: 30654957 DOI: 10.1016/j.funbio.2018.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 11/06/2018] [Indexed: 11/18/2022]
Abstract
Lasiodiplodia theobromae, a phytopathogenic fungus that causes peach gummosis, is considered one of the major constraints to peach production worldwide. Here, we report the characteristics of toxic metabolites and the proteomics investigation of the secreted proteins of L. theobromae from its in vitro culture. The phytotoxins of L. theobromae from the culture filtrate of Richard's liquid medium showed high toxicity on peach current year shoots with large lesion diameter and high gum weight. The toxicity measurement showed that 23.6 and 21.2 mg gum were induced from peach shoots by solvent fractions of ethyl acetate and dichloromethane, respectively, with significant differences from other organic solvents. A total of 23 proteins were identified by liquid chromatography-mass spectrometry from the in vitro secretome of L. theobromae. Sequence analysis indicated that 14 proteins were extracellular proteins based on signal peptides and localization. The expression profiles of the analyzed fungal genes were significantly upregulated from 1 day postinoculation (dpi) to 2 dpi, indicating that the early stage is an important stage for the infection of L. theobromae. The present study has provided insights into the extracellular phytotoxins and secreted proteins that are possibly associated with pathogenicity of the peach gummosis.
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Affiliation(s)
- Zhi Li
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - He Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Guohuai Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
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Mello TP, Bittencourt VCB, Liporagi-Lopes LC, Aor AC, Branquinha MH, Santos AL. Insights into the social life and obscure side of Scedosporium/Lomentospora species: ubiquitous, emerging and multidrug-resistant opportunistic pathogens. FUNGAL BIOL REV 2019. [DOI: 10.1016/j.fbr.2018.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Sueoka K, Chikama T, Pertiwi YD, Ko JA, Kiuchi Y, Sakaguchi T, Obana A. Antifungal efficacy of photodynamic therapy with TONS 504 for pathogenic filamentous fungi. Lasers Med Sci 2018; 34:743-747. [DOI: 10.1007/s10103-018-2654-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/27/2018] [Indexed: 12/17/2022]
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Analyses of the three 1-Cys Peroxiredoxins from Aspergillus fumigatus reveal that cytosolic Prx1 is central to H 2O 2 metabolism and virulence. Sci Rep 2018; 8:12314. [PMID: 30120327 PMCID: PMC6098058 DOI: 10.1038/s41598-018-30108-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/24/2018] [Indexed: 12/17/2022] Open
Abstract
Standing among the front defense strategies against pathogens, host phagocytic cells release various oxidants. Therefore, pathogens have to cope with stressful conditions at the site of infection. Peroxiredoxins (Prx) are highly reactive and abundant peroxidases that can support virulence and persistence of pathogens in distinct hosts. Here, we revealed that the opportunistic human pathogen A. fumigatus presents three 1-Cys Prx (Prx6 subfamily), which is unprecedented. We showed that PrxB and PrxC were in mitochondria, while Prx1 was in cytosol. As observed for other Prxs, recombinant Prx1 and PrxC decomposed H2O2 at elevated velocities (rate constants in the 107 M−1s−1 range). Deletion mutants for each Prx displayed higher sensitivity to oxidative challenge in comparison with the wild-type strain. Additionally, cytosolic Prx1 was important for A. fumigatus survival upon electron transport dysfunction. Expression of Prxs was dependent on the SakAHOG1 MAP kinase and the Yap1YAP1 transcription factor, a global regulator of the oxidative stress response in fungi. Finally, cytosolic Prx1 played a major role in pathogenicity, since it is required for full virulence, using a neutropenic mouse infection model. Our data indicate that the three 1-Cys Prxs act together to maintain the redox balance of A. fumigatus.
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Escobar N, Valdes ID, Keizer EM, Ordonez SR, Ohm RA, Wösten HAB, de Cock H. Expression profile analysis reveals that Aspergillus fumigatus but not Aspergillus niger makes type II epithelial lung cells less immunological alert. BMC Genomics 2018; 19:534. [PMID: 30005605 PMCID: PMC6044037 DOI: 10.1186/s12864-018-4895-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/25/2018] [Indexed: 12/17/2022] Open
Abstract
Background Aspergillus fumigatus is the main causative agent of aspergillosis. Infections rarely occur in immunocompetent individuals, indicating efficient clearance of conidia by pulmonary defense mechanisms. Other aspergilli like Aspergillus niger also cause infections but to a much lesser extent. Our previous studies showed that A. fumigatus and A. niger have different behavior in the presence of type II alveolar A549 epithelial cells. A. fumigatus conidia are more efficiently internalized by these cells and germination is delayed when compared to A. niger. In addition, hyphae that have escaped the epithelial cells grow parallel to the epithelium, while A. niger grows away from this cell layer. Results Here it is shown that global gene expression of A. fumigatus and A. niger is markedly different upon contact with A549 cells. A total of 545 and 473 genes of A. fumigatus and A. niger, respectively, were differentially expressed when compared to growth in the absence of A549 cells. Notably, only 53 genes (approximately 10%) were shared in these gene sets. The different response was also illustrated by the fact that only 4 out of 75 GO terms were shared that were enriched in the differentially expressed gene sets. The orthologues of A. fumigatus genes involved in hypoxia regulation and heat shock were also up-regulated in A. niger, whereas thioredoxin reductase and allergen genes were found up-regulated in A. fumigatus but down-regulated in A. niger. Infection with A. fumigatus resulted in only 62 up and 47 down-regulated genes in A549. These numbers were 17 and 34 in the case of A. niger. GO terms related with immune response were down-regulated upon exposure to A. fumigatus but not in the case of A. niger. This indicates that A. fumigatus reprograms A549 to be less immunologically alert. Conclusions Our dual transcriptomic analysis supports earlier observations of a marked difference in life style between A. fumigatus and A. niger when grown in the presence of type II epithelial cells. The results indicate important differences in gene expression, amongst others down regulation of immune response genes in lung epithelial cells by A. fumigatus but not by A niger. Electronic supplementary material The online version of this article (10.1186/s12864-018-4895-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Natalia Escobar
- Microbiology & Institute of Biomembranes, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Ivan D Valdes
- Microbiology & Institute of Biomembranes, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Esther M Keizer
- Microbiology & Institute of Biomembranes, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Soledad R Ordonez
- Department of Infectious Diseases and Immunology, Division Molecular Host Defence, Utrecht University, Yalelaan 1, 3584CL, Utrecht, The Netherlands
| | - Robin A Ohm
- Microbiology & Institute of Biomembranes, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Han A B Wösten
- Microbiology & Institute of Biomembranes, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Hans de Cock
- Microbiology & Institute of Biomembranes, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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