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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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Martin-Vicente A, Souza ACO, Guruceaga X, Thorn HI, Xie J, Nywening AV, Ge W, Fortwendel JR. A conserved fungal morphogenetic kinase regulates pathogenic growth in response to carbon source diversity. Nat Commun 2024; 15:8945. [PMID: 39414804 DOI: 10.1038/s41467-024-53358-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 10/09/2024] [Indexed: 10/18/2024] Open
Abstract
Fungal pathogens must exhibit strong nutritional plasticity, effectively sensing and utilizing diverse nutrients to support virulence. How the signals generated by nutritional sensing are efficiently translated to the morphogenetic machinery for optimal growth and support of virulence remains incompletely understood. Here, we show that the conserved morphogenesis-related kinase, CotA, imparts isoform-specific control over Aspergillus fumigatus invasive growth in host-mimicking environments and during infection. CotA-mediated invasive growth is responsive to exogenous carbon source quality, with only preferred carbon sources supporting hyphal morphogenesis in a mutant lacking one of two identified protein isoforms. Strikingly, we find that the CotA protein does not regulate, nor is cotA gene expression regulated by, the carbon catabolite repression system. Instead, we show that CotA partially mediates invasive growth in specific carbon sources and virulence through the conserved downstream effector and translational repressor, SsdA. Therefore, A. fumigatus CotA accomplishes its conserved morphogenetic functions to drive pathogenic growth by translating host-relevant carbon source quality signals into morphogenetic outputs for efficient tissue invasive growth.
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Affiliation(s)
- Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Ana Camila Oliveira Souza
- Department of Pharmacy and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Xabier Guruceaga
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Harrison I Thorn
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
- Graduate Program in Pharmaceutical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, 38103, USA
| | - Jinhong Xie
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
- Graduate Program in Pharmaceutical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, 38103, USA
| | - Ashley V Nywening
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, 38103, USA
| | - Wenbo Ge
- Department of Pharmacy and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jarrod R Fortwendel
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, 38103, USA.
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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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Anabosi D, Meir Z, Shadkchan Y, Handelman M, Abou-Kandil A, Yap A, Urlings D, Gold MS, Krappmann S, Haas H, Osherov N. Transcriptional response of Aspergillus fumigatus to copper and the role of the Cu chaperones. Virulence 2021; 12:2186-2200. [PMID: 34468270 PMCID: PMC8425704 DOI: 10.1080/21505594.2021.1958057] [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] [Indexed: 11/15/2022] Open
Abstract
Aspergillus fumigatus is the leading cause of life-threatening invasive mold infections in immunocompromised individuals. This ubiquitous saprophyte possesses several natural attributes allowing it to evade the immune system, including the ability to withstand high toxic Cu concentrations within the phagosomes of macrophages and neutrophils. We previously established that at high levels, Cu binds and activates the A. fumigatus transcription factor AceA, which upregulates the expression of the Cu exporter CrpA to expel excess Cu. Deletion of aceA or crpA result in extreme Cu sensitivity and attenuated virulence. To identify other elements participating in resistance to Cu, we performed a genome-wide analysis of the transcriptome by RNAseq to analyze the AceA-dependent response of A. fumigatus to excess Cu. We deleted key genes whose transcription was strongly upregulated by high Cu, including those encoding homologs of the three Cu chaperones cox17, atx1 and ccs1. Detailed analysis of these genes indicates that in A. fumigatus, cox17 is an essential gene with a possible role in respiration, the atxA gene product participates in reductive iron uptake and ccsA encodes the Cu chaperone activating A. fumigatus Sod1. Interestingly, although the ccsA-null strain was extremely sensitive to high Cu and oxidative stress, it was not attenuated in virulence in a mouse model of invasive pulmonary aspergillosis. Our work provides (i) a detailed view of the genome-wide transcriptional response of A. fumigatus to excess Cu, (ii) identification of the AceA-dependent transcriptome and (iii) analysis of the roles of the three Cu chaperones cox17, atxA and ccsA.
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Affiliation(s)
- Duaa Anabosi
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Zohar Meir
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Yana Shadkchan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Mariana Handelman
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Ammar Abou-Kandil
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Annie Yap
- Institute for Molecular Biology, Medical University Innsbruck, Austria
| | - Daniel Urlings
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Morgan S Gold
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Sven Krappmann
- Microbiology Institute, Clinical Microbiology, Immunology and Hygiene University Hospital and Friedrich-Alexander-University (FAU) of Erlangen-Nürnberg, Erlangen, Germany
| | - Hubertus Haas
- Institute for Molecular Biology, Medical University Innsbruck, Austria
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
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Liang T, Chen W, Yang X, Wang Q, Wan Z, Li R, Liu W. The Elevated Endogenous Reactive Oxygen Species Contribute to the Sensitivity of the Amphotericin B-Resistant Isolate of Aspergillus flavus to Triazoles and Echinocandins. Front Microbiol 2021; 12:680749. [PMID: 34413836 PMCID: PMC8369828 DOI: 10.3389/fmicb.2021.680749] [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: 03/15/2021] [Accepted: 07/13/2021] [Indexed: 12/22/2022] Open
Abstract
Aspergillus flavus has been frequently reported as the second cause of invasive aspergillosis (IA), as well as the leading cause in certain tropical countries. Amphotericin B (AMB) is a clinically important therapy option for a range of invasive fungal infections including invasive aspergillosis, and in vitro resistance to AMB was associated with poor outcomes in IA patients treated with AMB. Compared with the AMB-susceptible isolates of A. terreus, the AMB-resistant isolates of A. terreus showed a lower level of AMB-induced endogenous reactive oxygen species (ROS), which was an important cause of AMB resistance. In this study, we obtained one AMB-resistant isolate of A. flavus, with an AMB MIC of 32 μg/mL, which was sensitive to triazoles and echinocandins. This isolate presented elevated endogenous ROS levels, which strongly suggested that no contribution of decreased AMB-induced endogenous ROS for AMB-resistance, opposite to those observed in A. terreus. Further, we confirmed that the elevated endogenous ROS contributed to the sensitivity of the AMB-resistant A. flavus isolate to triazoles and echinocandins. Further investigation is needed to elucidate the causes of elevated endogenous ROS and the resistance mechanism to AMB in A. flavus.
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Affiliation(s)
- Tianyu Liang
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Wei Chen
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Xinyu Yang
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Qiqi Wang
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Zhe Wan
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Ruoyu Li
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Wei Liu
- Department of Dermatology and Venerology, Peking University First Hospital, National Clinical Research Center for Skin and Immune Diseases, Research Center for Medical Mycology, Peking University, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
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Mills B, Radhakrishnan N, Karthikeyan Rajapandian SG, Rameshkumar G, Lalitha P, Prajna NV. The role of fungi in fungal keratitis. Exp Eye Res 2020; 202:108372. [PMID: 33249061 DOI: 10.1016/j.exer.2020.108372] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/07/2020] [Accepted: 11/22/2020] [Indexed: 12/20/2022]
Abstract
Fungal keratitis (FK) accounts for approximately half of the microbial keratitis encountered in low middle income countries (LMICs) and predominantly affect the working rural-poor. FK causes significant morbidity with the majority of patients left with moderate or worse visual impairment and approximately 25% requiring expensive and often unsuccessful surgical interventions. The severity of FK and the resultant corneal damage or resolution can be attributed to i) the virulence and bioburden of the fungal pathogen, ii) the host defense mechanism and immune response and iii) sub-optimal diagnostics and anti-fungal treatment strategies. This review provides a comprehensive overview of the multifaceted components that drive FK progression and resolution, highlighting where knowledge gaps exist and areas that warrant further research.
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Affiliation(s)
- Bethany Mills
- Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Naveen Radhakrishnan
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India
| | | | | | - Prajna Lalitha
- Department of Ocular Microbiology, Aravind Eye Hospital, Madurai, India
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India.
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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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Transcriptome Analysis of Dimorphic Fungus Sporothrix schenckii Exposed to Temperature Stress. Int Microbiol 2020; 24:25-35. [PMID: 32691258 PMCID: PMC7873001 DOI: 10.1007/s10123-020-00136-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 06/12/2020] [Accepted: 07/14/2020] [Indexed: 11/03/2022]
Abstract
PURPOSE Sporothrix schenckii is a thermally dimorphic fungus. In a saprotrophic environment or culturing at 25 °C, it grows as mycelia, whereas in host tissues or culturing at 37 °C, it undergoes dimorphic transition and division into pathogenic yeast cells. S. schenckii can cause serious disseminated sporotrichosis in immunocompromised hosts and presents an emerging global health problem. The mycelium-to-yeast transition was a consequence of the adaptive process to different environment. Some studies showed that the transition was significantly related to the virulence and pathogenesis of dimorphic fungi. However the genetic mechanisms of this complicated biological process are poorly understood. METHOD Our study presented a comparative transcriptomic analysis perspective on temperature stress in a visceral isolates of S. schenckii, obtaining more genetic information related to dimorphic transition. RESULTS The 9.38 Gbp dataset was generated and assembled into 14,423 unigenes. Compared with gene and protein databases, 9561 unigenes were annotated. Comparative analysis identified 1259 genes expressed differentially in mycelium and yeast phase, and were categorized into a number of important biological processes, such as synthesis and metabolism, transmembrane transport, biocatalysis, oxidation reduction, and cellular signal transduction. CONCLUSIONS The findings suggested that temperature-dependent transition was tightly associated with stress adaptation, growth and development, signal regulation, adhesion, and colonization, which was predicted to be related with virulence and pathogenesis. Collection of these data should offer fine-scale insights into the mechanisms of dimorphism and pathogenesis of S. schenckii, and meanwhile facilitate the evolutionary and function studies of other dimorphic fungi.
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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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Silva RLH, Rosa-Milani E, Brunaldi MO, Maffei CML. Murine model of invasive pulmonary Aspergillosis: Follow-up of tissue injury, fungal burden and mortality with distinct elastase production strains. J Mycol Med 2018; 29:112-119. [PMID: 30446390 DOI: 10.1016/j.mycmed.2018.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 10/27/2022]
Abstract
To study invasive pulmonary Aspergillosis (IPA), we depleted neutrophils in mice using the monoclonal antibody anti-Gr-1/Ly-6G. Immunocompetent and neutropenic mice were infected via intratracheal with conidia of Aspergillus fumigatus clinical isolates, characterized as either higher or lower elastase producers. Neutropenic animals exhibited 100% mortality in 5 days, for both strains, and were observed survival curves overlapped, lungs with angioinvasion, rupture of bronchial and vascular walls, associated with exuberance of conidia filamentation. The immunocompetent animals infected with the lower elastase producer strain presented with upregulated inflammatory processes, and a lack of conidia filamentation in the tissue. The fungal burden in the lungs was not different in the immunocompetent and neutropenic groups. These findings confirm the protective role of neutrophils against A. fumigatus and suggest that the fungal elastinolytic activity is not a critical virulence factor but may be involved in tissue injury.
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Affiliation(s)
- R L H Silva
- Department of Pathology and Legal Medicine, Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes, 3900 Ribeirão Preto, 14049-900 São Paulo, Brazil.
| | - E Rosa-Milani
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes, 3900 Ribeirão Preto, 14049-900 São Paulo Brazil.
| | - M O Brunaldi
- Department of Pathology and Legal Medicine, Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes, 3900 Ribeirão Preto, 14049-900 São Paulo, Brazil.
| | - C M L Maffei
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes, 3900 Ribeirão Preto, 14049-900 São Paulo Brazil.
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Identification and Characterization of Key Charged Residues in the Cofilin Protein Involved in Azole Susceptibility, Apoptosis, and Virulence of Aspergillus fumigatus. Antimicrob Agents Chemother 2018; 62:AAC.01659-17. [PMID: 29483117 DOI: 10.1128/aac.01659-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/10/2018] [Indexed: 12/28/2022] Open
Abstract
Through some specific amino acid residues, cofilin, a ubiquitous actin depolymerization factor, can significantly affect mitochondrial function related to drug resistance and apoptosis in Saccharomyces cerevisiae; however, this modulation in a major fungal pathogen, Aspergillus fumigatus, was still unclear. Hereby, it was found, first, that mutations on several charged residues in cofilin to alanine, D19A-R21A, E48A, and K36A, increased the formation of reactive oxygen species and induced apoptosis along with typical hallmarks, including mitochondrial membrane potential depolarization, cytochrome c release, upregulation of metacaspases, and DNA cleavage, in A. fumigatus Two of these mutations (D19A-R21A and K36A) increased acetyl coenzyme A and ATP concentrations by triggering fatty acid β-oxidation. The upregulated acetyl coenzyme A affected the ergosterol biosynthetic pathway, leading to overexpression of cyp51A and -B, while excess ATP fueled ATP-binding cassette transporters. Besides, both of these mutations reduced the susceptibility of A. fumigatus to azole drugs and enhanced the virulence of A. fumigatus in a Galleria mellonella infection model. Taken together, novel and key charged residues in cofilin were identified to be essential modules regulating the mitochondrial function involved in azole susceptibility, apoptosis, and virulence of A. fumigatus.
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Abstract
The balance between reactive oxygen species and reactive nitrogen species production by the host and stress response by fungi is a key axis of the host-pathogen interaction. This review will describe emerging themes in fungal pathogenesis underpinning this axis.
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Affiliation(s)
- Adilia Warris
- Medical Research Centre for Medical Mycology, Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, UK
| | - Elizabeth R Ballou
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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Oxidative Stress Response Tips the Balance in Aspergillus terreus Amphotericin B Resistance. Antimicrob Agents Chemother 2017; 61:AAC.00670-17. [PMID: 28739793 DOI: 10.1128/aac.00670-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 07/03/2017] [Indexed: 01/24/2023] Open
Abstract
In this study, we characterize the impact of antioxidative enzymes in amphotericin B (AmB)-resistant (ATR) and rare AmB-susceptible (ATS) clinical Aspergillus terreus isolates. We elucidate expression profiles of superoxide dismutase (SOD)- and catalase (CAT)-encoding genes, enzymatic activities of SODs, and superoxide anion production and signaling pathways involved in the oxidative stress response (OSR) in ATS and ATR strains under AmB treatment conditions. We show that ATR strains possess almost doubled basal SOD activity compared to that of ATS strains and that ATR strains exhibit an enhanced OSR, with significantly higher sod2 mRNA levels and significantly increased cat transcripts in ATR strains upon AmB treatment. In particular, inhibition of SOD and CAT proteins renders resistant isolates considerably susceptible to the drug in vitro In conclusion, this study shows that SODs and CATs are crucial for AmB resistance in A. terreus and that targeting the OSR might offer new treatment perspectives for resistant species.
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Staerck C, Gastebois A, Vandeputte P, Calenda A, Larcher G, Gillmann L, Papon N, Bouchara JP, Fleury MJ. Microbial antioxidant defense enzymes. Microb Pathog 2017. [DOI: 10.1016/j.micpath.2017.06.015] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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15
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Myers RR, Smith TD, Elsawa SF, Puel O, Tadrist S, Calvo AM. rtfA controls development, secondary metabolism, and virulence in Aspergillus fumigatus. PLoS One 2017; 12:e0176702. [PMID: 28453536 PMCID: PMC5409149 DOI: 10.1371/journal.pone.0176702] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/14/2017] [Indexed: 12/18/2022] Open
Abstract
Invasive aspergillosis by Aspergillus fumigatus is a leading cause of infection-related mortality in immune-compromised patients. In order to discover potential genetic targets to control A. fumigatus infections we characterized rtfA, a gene encoding a putative RNA polymerase II transcription elongation factor-like protein. Our recent work has shown that the rtfA ortholog in the model fungus Aspergillus nidulans regulates morphogenesis and secondary metabolism. The present study on the opportunistic pathogen A. fumigatus rtfA gene revealed that this gene influences fungal growth and conidiation, as well as production of the secondary metabolites tryptoquivaline F, pseurotin A, fumiquinazoline C, festuclavine, and fumigaclavines A, B and C. Additionally, rtfA influences protease activity levels, the sensitivity to oxidative stress and adhesion capacity, all factors important in pathogenicity. Furthermore, rtfA was shown to be indispensable for normal virulence using Galleria mellonella as well as murine infection model systems.
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Affiliation(s)
- Ryan R. Myers
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, United States of America
| | - Timothy D. Smith
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, United States of America
| | - Sherine F. Elsawa
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, United States of America
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Souraia Tadrist
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Ana M. Calvo
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, United States of America
- * E-mail:
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Bultman KM, Kowalski CH, Cramer RA. Aspergillus fumigatus virulence through the lens of transcription factors. Med Mycol 2016; 55:24-38. [PMID: 27816905 DOI: 10.1093/mmy/myw120] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 08/19/2016] [Accepted: 10/17/2016] [Indexed: 02/07/2023] Open
Abstract
Invasive aspergillosis (IA), most commonly caused by the filamentous fungus Aspergillus fumigatus, occurs in immune compromised individuals. The ability of A. fumigatus to proliferate in a multitude of environments is hypothesized to contribute to its pathogenicity and virulence. Transcription factors (TF) have long been recognized as critical proteins for fungal pathogenicity, as many are known to play important roles in the transcriptional regulation of pathways implicated in virulence. Such pathways include regulation of conidiation and development, adhesion, nutrient acquisition, adaptation to environmental stress, and interactions with the host immune system among others. In both murine and insect models of IA, TF loss of function in A. fumigatus results in cases of hyper- and hypovirulence as determined through host survival, fungal burden, and immune response analyses. Consequently, the study of specific TFs in A. fumigatus has revealed important insights into mechanisms of pathogenicity and virulence. Although in vitro studies have identified virulence-related functions of specific TFs, the full picture of their in vivo functions remain largely enigmatic and an exciting area of current research. Moreover, the vast majority of TFs remain to be characterized and studied in this important human pathogen. Here in this mini-review we provide an overview of selected TFs in A. fumigatus and their contribution to our understanding of this important human pathogen's pathogenicity and virulence.
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Affiliation(s)
- Katherine M Bultman
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Caitlin H Kowalski
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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Wang Z, Jin K, Xia Y. Transcriptional analysis of the conidiation pattern shift of the entomopathogenic fungus Metarhizium acridum in response to different nutrients. BMC Genomics 2016; 17:586. [PMID: 27506833 PMCID: PMC4979188 DOI: 10.1186/s12864-016-2971-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/27/2016] [Indexed: 12/14/2022] Open
Abstract
Background Most fungi, including entomopathogenic fungi, have two different conidiation patterns, normal and microcycle conidiation, under different culture conditions, eg, in media containing different nutrients. However, the mechanisms underlying the conidiation pattern shift are poorly understood. Results In this study, Metarhizium acridum undergoing microcycle conidiation on sucrose yeast extract agar (SYA) medium shifted to normal conidiation when the medium was supplemented with sucrose, nitrate, or phosphate. By linking changes in nutrients with the conidiation pattern shift and transcriptional changes, we obtained conidiation pattern shift libraries by Solexa/Illumina deep-sequencing technology. A comparative analysis demonstrated that the expression of 137 genes was up-regulated during the shift to normal conidiation, while the expression of 436 genes was up-regulated at the microcycle conidiation stage. A comparison of subtractive libraries revealed that 83, 216, and 168 genes were related to sucrose-induced, nitrate-induced, and phosphate-induced conidiation pattern shifts, respectively. The expression of 217 genes whose expression was specific to microcycle conidiation was further analyzed by the gene expression profiling via multigene concatemers method using mRNA isolated from M. acridum grown on SYA and the four normal conidiation media. The expression of 142 genes was confirmed to be up-regulated on standard SYA medium. Of these 142 genes, 101 encode hypothetical proteins or proteins of unknown function, and only 41 genes encode proteins with putative functions. Of these 41 genes, 18 are related to cell growth, 10 are related to cell proliferation, three are related to the cell cycle, three are related to cell differentiation, two are related to cell wall synthesis, two are related to cell division, and seven have other functions. These results indicate that the conidiation pattern shift in M. acridum mainly results from changes in cell growth and proliferation. Conclusions The results indicate that M. acridum shifts conidiation pattern from microcycle conidiation to normal conidiation when there is increased sucrose, nitrate, or phosphate in the medium during microcycle conidiation. The regulation of conidiation patterning is a complex process involving the cell cycle and metabolism of M. acridum. This study provides essential information about the molecular mechanism of the induction of the conidiation pattern shift by single nutrients. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2971-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhenglong Wang
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 400045, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing University, Chongqing, 400045, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Kai Jin
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 400045, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing University, Chongqing, 400045, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 400045, People's Republic of China. .,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing University, Chongqing, 400045, People's Republic of China. .,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing University, Chongqing, 400045, People's Republic of China.
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18
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Weerasinghe H, Payne M, Beard S, Andrianopoulos A. Organism-wide studies into pathogenicity and morphogenesis in Talaromyces marneffei. Future Microbiol 2016; 11:511-26. [PMID: 27073980 DOI: 10.2217/fmb.16.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Organism-wide approaches examining the genetic mechanisms controlling growth and proliferation have proven to be a powerful tool in the study of pathogenic fungi. For many fungal pathogens techniques to study transcription and protein expression are particularly useful, and offer insights into infection processes by these species. Here we discuss the use of approaches such as differential display, suppression subtractive hybridization, microarray, RNA-seq, proteomics, genetic manipulation and infection models for the AIDS-defining pathogen Talaromyces marneffei. Together these methods have broadened our understanding of the biological processes, and genes that underlie them, which are involved in switching between the saprophytic and pathogenic states of T. marneffei, the maintenance of these two specialized cell types and its ability to cause disease.
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Affiliation(s)
- Harshini Weerasinghe
- Genetics, Genomics & Development, School of BioSciences, University of Melbourne, Victoria 3010, Australia
| | - Michael Payne
- Genetics, Genomics & Development, School of BioSciences, University of Melbourne, Victoria 3010, Australia
| | - Sally Beard
- Genetics, Genomics & Development, School of BioSciences, University of Melbourne, Victoria 3010, Australia
| | - Alex Andrianopoulos
- Genetics, Genomics & Development, School of BioSciences, University of Melbourne, Victoria 3010, Australia
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19
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Fan Z, Yu H, Guo Q, He D, Xue B, Xie X, Yokoyama K, Wang L. Identification and characterization of an anti-oxidative stress-associated mutant of Aspergillus fumigatus transformed by Agrobacterium tumefaciens. Mol Med Rep 2016; 13:2367-76. [PMID: 26847000 PMCID: PMC4768994 DOI: 10.3892/mmr.2016.4839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 10/29/2015] [Indexed: 01/20/2023] Open
Abstract
Aspergillus fumigatus is one of the most common opportunistic pathogenic fungi, surviving in various environmental conditions. Maintenance of the redox homeostasis of the fungus relies upon the well‑organized regulation between reactive oxygen species generated by immune cells or its own organelles, and the activated anti‑oxidative stress mechanism. To investigate such a mechanism, the present study obtained a number of randomly‑inserted mutants of A. fumigatus, mediated by Agrobacterium tumefaciens. In addition, a high throughput hydrogen peroxide screening system was established to examine ~1,000 mutants. A total of 100 mutants exhibited changes in hydrogen peroxide sensitivity, among which a significant increase in sensitivity was observed in the AFM2658 mutant. Further investigations of the mutant were also performed, in which the sequence of this mutant was characterized using thermal asymmetric interlaced‑polymerase chain reaction. This revealed that the insertion site was located on chromosome 2 afu1_92, and the 96 bp sequence was knocked out, which partially comprised a sequence localized between the integral membrane protein coding region and the helix‑loop‑helix transcription factor coding region. A decrease in the levels of anti‑oxidative stress‑associated mRNAs were observed, and an increase in reactive oxygen species were detected using fluorescence. The results of the present study demonstrated that this sequence may have a protective role in A. fumigatus in the presence of oxidative stress.
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Affiliation(s)
- Zhongqi Fan
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Huimei Yu
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Qi Guo
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Dan He
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Baiji Xue
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Xiangli Xie
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Koji Yokoyama
- Medical Mycology Research Center, Chiba University, Chiba 260‑8673, Japan
| | - Li Wang
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
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20
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Rohr AC, Campleman SL, Long CM, Peterson MK, Weatherstone S, Quick W, Lewis A. Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:8542-605. [PMID: 26206568 PMCID: PMC4515735 DOI: 10.3390/ijerph120708542] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/03/2015] [Accepted: 07/14/2015] [Indexed: 12/19/2022]
Abstract
Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios--pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended.
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Affiliation(s)
- Annette C Rohr
- Electric Power Research Institute, Palo Alto, CA 94304, USA.
| | | | | | | | - Susan Weatherstone
- ON Technologies (Ratcliffe) Ltd., Ratcliffe on Soar, Nottinghamshire, NG11 0EE, UK.
| | - Will Quick
- ON Technologies (Ratcliffe) Ltd., Ratcliffe on Soar, Nottinghamshire, NG11 0EE, UK.
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21
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Aki K, Okubo Y, Nanjo H, Ishiwatari T, Nihonyanagi Y, Tochigi N, Wakayama M, Nemoto T, Fukutake K, Shinozaki M, Hori Y, Masuda H, Shibuya K. Genomic Analysis of Single Nucleotide Polymorphisms Asp299Gly and Thr399Ile in Japanese Patients with Invasive Aspergillosis. Jpn J Infect Dis 2015; 68:330-2. [PMID: 25766605 DOI: 10.7883/yoken.jjid.2014.420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Single nucleotide polymorphisms (SNPs) 1063A/G (Asp299Gly) and 1363C/T (Thr399Ile) in the gene encoding Toll-like receptor 4 (TLR4) increase susceptibility to invasive aspergillosis. However, limited information is available on the prevalence of these SNPs in Japan. Therefore, we surveyed these TLR4 SNPs by using formalin-fixed and paraffin-embedded tissue blocks obtained from autopsies of patients with invasive pulmonary aspergillosis. Tissue samples of approximately 30% patients were included in genomic analysis. However, none of these samples showed the presence of TLR4 Asp299Gly and Thr399Ile polymorphisms. Thus, the present study provided information on the prevalence of TLR4 SNPs in Japanese patients with invasive aspergillosis and indicated that these SNPs played a minor role in increasing the susceptibility of Japanese individuals to invasive aspergillosis.
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Affiliation(s)
- Kyoko Aki
- Department of Surgical Pathology, Toho University School of Medicine
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22
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Histopathological implications of Aspergillus infection in lung. Mediators Inflamm 2013; 2013:809798. [PMID: 24347836 PMCID: PMC3853935 DOI: 10.1155/2013/809798] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/26/2013] [Accepted: 10/29/2013] [Indexed: 12/20/2022] Open
Abstract
This paper opens with a discussion on the significance of invasive fungal infections in advanced contemporary medicine, with an emphasis on the intractability of disease management and the difficulties of diagnosis. This is followed by a discussion concerning classification, histopathological features, and pathophysiology. While it has been largely accepted that Aspergillus species is recognized by cellular receptors and attacked by neutrophils, the radiological and macroscopic findings linking infection with neutropenia remain unconfirmed. In an effort to gain a better understanding of the pathophysiology and pathogenesis of invasive aspergillosis, we wish to emphasize the utility of radiological and histopathological examinations since these can provide detailed information on the extremely complex interaction between the causative microbes and tissue responses. A review of noninvasive or semi-invasive aspergillosis is also provided, with particular emphasis on chronic necrotizing pulmonary aspergillosis, which is recognized as a transition form of simple pulmonary aspergilloma and invasive pulmonary aspergillosis, although few findings have been reported in this area.
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23
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Shin KS, Park HS, Kim YH, Yu JH. Comparative proteomic analyses reveal that FlbA down-regulates gliT expression and SOD activity in Aspergillus fumigatus. J Proteomics 2013; 87:40-52. [DOI: 10.1016/j.jprot.2013.05.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 05/05/2013] [Accepted: 05/09/2013] [Indexed: 10/26/2022]
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Comparative transcriptomics of infectious spores from the fungal pathogen Histoplasma capsulatum reveals a core set of transcripts that specify infectious and pathogenic states. EUKARYOTIC CELL 2013; 12:828-52. [PMID: 23563482 DOI: 10.1128/ec.00069-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Histoplasma capsulatum is a fungal pathogen that infects both healthy and immunocompromised hosts. In regions where it is endemic, H. capsulatum grows in the soil and causes respiratory and systemic disease when inhaled by humans. An interesting aspect of H. capsulatum biology is that it adopts specialized developmental programs in response to its environment. In the soil, it grows as filamentous chains of cells (mycelia) that produce asexual spores (conidia). When the soil is disrupted, conidia aerosolize and are inhaled by mammalian hosts. Inside a host, conidia germinate into yeast-form cells that colonize immune cells and cause disease. Despite the ability of conidia to initiate infection and disease, they have not been explored on a molecular level. We developed methods to purify H. capsulatum conidia, and we show here that these cells germinate into filaments at room temperature and into yeast-form cells at 37°C. Conidia internalized by macrophages germinate into the yeast form and proliferate within macrophages, ultimately lysing the host cells. Similarly, infection of mice with purified conidia is sufficient to establish infection and yield viable yeast-form cells in vivo. To characterize conidia on a molecular level, we performed whole-genome expression profiling of conidia, yeast, and mycelia from two highly divergent H. capsulatum strains. In parallel, we used homology and protein domain analysis to manually annotate the predicted genes of both strains. Analyses of the resultant data defined sets of transcripts that reflect the unique molecular states of H. capsulatum conidia, yeast, and mycelia.
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25
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Homology modeling and phylogenetic relationships of catalases of an opportunistic pathogen Rhizopus oryzae. Life Sci 2012; 91:115-26. [DOI: 10.1016/j.lfs.2012.06.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/24/2012] [Accepted: 06/15/2012] [Indexed: 11/19/2022]
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26
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Cohn CA, Lemieux CL, Long AS, Kystol J, Vogel U, White PA, Madsen AM. Physical-chemical and microbiological characterization, and mutagenic activity of airborne PM sampled in a biomass-fueled electrical production facility. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:319-330. [PMID: 20872826 DOI: 10.1002/em.20628] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Accepted: 07/28/2010] [Indexed: 05/29/2023]
Abstract
Biomass combustion is used in heating and electric power generation in many areas of the world. Airborne particulate matter (PM) is released when biomass is brought to a facility, stored, and combusted. Occupational exposure to airborne PM within biomass-fueled facilities may lead to health problems. In March and August of 2006, airborne PM was collected from a biomass-fueled facility located in Denmark. In addition, source-specific PM was generated from straw and wood pellets using a rotating drum. The PM was analyzed for polycyclic aromatic hydrocarbons (PAHs), metals, microbial components, mutagenic activity, and ability to generate highly reactive oxygen species (hROS) in cell-free aqueous suspensions. PM collected from the boiler room and the biomass storage hall had higher levels of mutagenic activity, PAHs and metals, and a higher hROS generating potential than the source specific PM. The mutagenic activity was generally more potent without S9 activation, and on the metabolically enhanced strain YG1041, relative to TA98. Significant correlations were found between mutagenicity on YG1041 (without S9) and PAH concentration and mutagenicity on YG1041 (with S9) and hROS generating ability. PM collected in March was more toxic than PM collected in August. Overall, airborne PM collected from the facility, especially that from the boiler room, were more toxic than PM generated from straw and wood chips. The results suggest that exposure to combustion PM in a biomass-fueled facility, which likely includes PM from biomass combustion as well as internal combustion vehicles, may contribute to an elevated risk of adverse health effects.
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Affiliation(s)
- Corey A Cohn
- National Research Centre for the Working Environment, Copenhagen, Denmark
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27
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Kumar A, Ahmed R, Singh PK, Shukla PK. Identification of virulence factors and diagnostic markers using immunosecretome of Aspergillus fumigatus. J Proteomics 2011; 74:1104-12. [PMID: 21536156 DOI: 10.1016/j.jprot.2011.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 03/15/2011] [Accepted: 04/04/2011] [Indexed: 10/18/2022]
Abstract
Aspergillus fumigatus is a prime causative agent for various allergic and invasive aspergillosis. There has been a dramatic increase of such cases in last three decades yet the early diagnosis and virulence factor identification remains the challenge. In the present study secretome analysis of proteins isolated from the culture filtrate was done by 2D gel electrophoresis coupled with MS/MS and the immunosecretome analysis was carried out using immunoblotting of 2D transfer blots and probed with the sera of patients, immunized rabbit and mice. The identified proteins were analyzed further for homology with human proteins by BLAST search and for secretory signal by SignalP. A total of 65 protein spots from 2D gel resulted in identification of 24 different proteins along with their isoforms and out of which 15 proteins were identified as immunogenic in human. These findings may be helpful in the identification of virulence factors involved in aspergillosis and also useful as diagnostic markers.
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Affiliation(s)
- Awanit Kumar
- Medical Mycology Lab, Division of Fermentation Technology, CSIR-Central Drug Research Institute, Lucknow-226 001, India
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28
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Morton CO, Varga JJ, Hornbach A, Mezger M, Sennefelder H, Kneitz S, Kurzai O, Krappmann S, Einsele H, Nierman WC, Rogers TR, Loeffler J. The temporal dynamics of differential gene expression in Aspergillus fumigatus interacting with human immature dendritic cells in vitro. PLoS One 2011; 6:e16016. [PMID: 21264256 PMCID: PMC3021540 DOI: 10.1371/journal.pone.0016016] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 12/03/2010] [Indexed: 12/18/2022] Open
Abstract
Dendritic cells (DC) are the most important antigen presenting cells and play a pivotal role in host immunity to infectious agents by acting as a bridge between the innate and adaptive immune systems. Monocyte-derived immature DCs (iDC) were infected with viable resting conidia of Aspergillus fumigatus (Af293) for 12 hours at an MOI of 5; cells were sampled every three hours. RNA was extracted from both organisms at each time point and hybridised to microarrays. iDC cell death increased at 6 h in the presence of A. fumigatus which coincided with fungal germ tube emergence; >80% of conidia were associated with iDC. Over the time course A. fumigatus differentially regulated 210 genes, FunCat analysis indicated significant up-regulation of genes involved in fermentation, drug transport, pathogenesis and response to oxidative stress. Genes related to cytotoxicity were differentially regulated but the gliotoxin biosynthesis genes were down regulated over the time course, while Aspf1 was up-regulated at 9 h and 12 h. There was an up-regulation of genes in the subtelomeric regions of the genome as the interaction progressed. The genes up-regulated by iDC in the presence of A. fumigatus indicated that they were producing a pro-inflammatory response which was consistent with previous transcriptome studies of iDC interacting with A. fumigatus germ tubes. This study shows that A. fumigatus adapts to phagocytosis by iDCs by utilising genes that allow it to survive the interaction rather than just up-regulation of specific virulence genes.
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Affiliation(s)
- Charles O. Morton
- Department of Clinical Microbiology, Trinity College Dublin, Dublin, Ireland
| | - John J. Varga
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Anke Hornbach
- Medizinische Klinik and Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Markus Mezger
- Medizinische Klinik and Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Helga Sennefelder
- Medizinische Klinik and Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Susanne Kneitz
- Labor für Microarray Anwendungen, Interdisziplinäres Zentrum für Klinische Forschung, Würzburg, Germany
| | - Oliver Kurzai
- Septomics Research Centre, Friedrich-Schiller-Universität Jena, Leibniz Institute for Natural Products Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany
| | - Sven Krappmann
- Zentrum für Infektionsforschung, Universität Würzburg, Würzburg, Germany
| | - Hermann Einsele
- Medizinische Klinik and Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - William C. Nierman
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Thomas R. Rogers
- Department of Clinical Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Juergen Loeffler
- Medizinische Klinik and Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
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Human leukocytes kill Aspergillus nidulans by reactive oxygen species-independent mechanisms. Infect Immun 2010; 79:767-73. [PMID: 21078850 DOI: 10.1128/iai.00921-10] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Invasive aspergillosis is a major threat for patients suffering from chronic granulomatous disease (CGD). Although Aspergillus fumigatus is the most commonly encountered Aspergillus species, the presence of A. nidulans appears to be disproportionately high in CGD patients. The purpose of this study was to investigate the involvement of the NADPH oxidase and the resulting reactive oxygen species (ROS) in host defense against fungi and to clarify their relationship toward A. nidulans. Murine CGD alveolar macrophages (AM) and polymorphonuclear leukocytes (PMN) and peripheral blood mononuclear cells (PBMC) from healthy controls and CGD patients were challenged with either A. fumigatus or A. nidulans. Analysis of the antifungal effects of ROS revealed that A. nidulans, in contrast to A. fumigatus, is not susceptible to ROS. In addition, infection with live A. nidulans did not result in any measurable ROS release. Remarkably, human CGD PMN and PBMC and murine CGD AM were at least equipotent at arresting conidial germination compared to healthy controls. Blocking of the NADPH oxidase resulted in significantly reduced damage of A. fumigatus but did not affect A. nidulans hyphae. Furthermore, the microbicidal activity of CGD PMN was maintained toward A. nidulans but not A. fumigatus. In summary, antifungal resistance to A. nidulans is not directly ROS related. The etiology of A. nidulans infections in CGD cannot be explained by the simple absence of the direct microbicidal effect of ROS. In vivo, the NADPH oxidase is a critical regulator of innate immunity whose unraveling will improve our understanding of fungal pathogenesis in CGD.
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Singh B, Oellerich M, Kumar R, Kumar M, Bhadoria DP, Reichard U, Gupta VK, Sharma GL, Asif AR. Immuno-Reactive Molecules Identified from the Secreted Proteome of Aspergillus fumigatus. J Proteome Res 2010; 9:5517-29. [DOI: 10.1021/pr100604x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Bharat Singh
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Michael Oellerich
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Ram Kumar
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Manish Kumar
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Dharam P. Bhadoria
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Utz Reichard
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Vijay K. Gupta
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Gainda L. Sharma
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
| | - Abdul R. Asif
- Division of Diagnostics and Biochemistry, Institute of Genomics and Integrative Biology, University Campus, Mall Road, Delhi-110007, India, Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str.40, D-37075 Goettingen, Germany, Department of Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi-110002, India, Department of Medical Microbiology and National Reference Center for Systemic Mycoses, University Medical Center Goettingen, Kreuzburgring 57, D
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Nakayama H, Shibuya K, Kimura M, Ueda M, Iwabuchi S. Histopathological study of candidal infection in the central nervous system. ACTA ACUST UNITED AC 2010; 51:31-45. [PMID: 20185869 DOI: 10.3314/jjmm.51.31] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In recent years, incidence of invasive fungal infection has been increasing, mostly due to advances in + medicine that may produce immunocompromised individuals. Candidial infection in the central nervous system (CNS) is one of the most serious forms of blood stream infection of Candida sp. and mortality is known to be more than 50%. In this research, we employed 27 autopsies with confirmed in vasive CNS yeast infection which were confirmed. In addition to detailed morphological analysis of yeast cells in lesions, in situ hybridization was carried out with an originally designed Candida-specific peptide nucleic acid (PNA) probe to identify the candidial infection of each patient. This was followed by histopathological investigation: invasiveness, shape, and distribution of yeast or yeasts with pseudohyphal growth, and a study regarding the correlation between histological characteristics and number of leukocytes in the peripheral blood just before death. Results showed that the, supratentorial region was the most common area of disseminated candidial infection in CNS, and that density was highest in the cerebral gray matter followed by the white matter and basal ganglia. On the other hand, regarding the lesions developed in the cortical area, the average distance from the brain surface was 4.026 mm. This area corresponding to the deeper cortex has a characteristic arterial structure that refers hairpin curving reverse. The structure may contribute to the high incidence of candidial foci in the deeper cortex, because of the increase in shear stress.
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Affiliation(s)
- Haruo Nakayama
- 2nd Department of Neurosurgery, Kinki University School of Medicine, Japan
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Kim KH, Willger SD, Park SW, Puttikamonkul S, Grahl N, Cho Y, Mukhopadhyay B, Cramer RA, Lawrence CB. TmpL, a transmembrane protein required for intracellular redox homeostasis and virulence in a plant and an animal fungal pathogen. PLoS Pathog 2009; 5:e1000653. [PMID: 19893627 PMCID: PMC2766074 DOI: 10.1371/journal.ppat.1000653] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 10/13/2009] [Indexed: 11/30/2022] Open
Abstract
The regulation of intracellular levels of reactive oxygen species (ROS) is critical for developmental differentiation and virulence of many pathogenic fungi. In this report we demonstrate that a novel transmembrane protein, TmpL, is necessary for regulation of intracellular ROS levels and tolerance to external ROS, and is required for infection of plants by the necrotroph Alternaria brassicicola and for infection of mammals by the human pathogen Aspergillus fumigatus. In both fungi, tmpL encodes a predicted hybrid membrane protein containing an AMP-binding domain, six putative transmembrane domains, and an experimentally-validated FAD/NAD(P)-binding domain. Localization and gene expression analyses in A. brassicicola indicated that TmpL is associated with the Woronin body, a specialized peroxisome, and strongly expressed during conidiation and initial invasive growth in planta. A. brassicicola and A. fumigatus ΔtmpL strains exhibited abnormal conidiogenesis, accelerated aging, enhanced oxidative burst during conidiation, and hypersensitivity to oxidative stress when compared to wild-type or reconstituted strains. Moreover, A. brassicicola ΔtmpL strains, although capable of initial penetration, exhibited dramatically reduced invasive growth on Brassicas and Arabidopsis. Similarly, an A. fumigatus ΔtmpL mutant was dramatically less virulent than the wild-type and reconstituted strains in a murine model of invasive aspergillosis. Constitutive expression of the A. brassicicola yap1 ortholog in an A. brassicicola ΔtmpL strain resulted in high expression levels of genes associated with oxidative stress tolerance. Overexpression of yap1 in the ΔtmpL background complemented the majority of observed developmental phenotypic changes and partially restored virulence on plants. Yap1-GFP fusion strains utilizing the native yap1 promoter exhibited constitutive nuclear localization in the A. brassicicola ΔtmpL background. Collectively, we have discovered a novel protein involved in the virulence of both plant and animal fungal pathogens. Our results strongly suggest that dysregulation of oxidative stress homeostasis in the absence of TmpL is the underpinning cause of the developmental and virulence defects observed in these studies. The critical roles of reactive oxygen species (ROS) in fungal development and virulence have been well established over the past half a century since the first experimental detection of hydrogen peroxide in fungal cells by Bach (1950). In the cell, ROS act as signaling molecules regulating physiological responses and developmental processes and are also involved in sophisticated virulence processes for many pathogenic fungi. Therefore, uncovering the biological roles of cellular ROS appears to be very important in understanding fungal development and virulence. Currently we have limited knowledge of how intracellular ROS are generated by fungal cells and which cellular ROS regulatory mechanisms are involved in establishing homeostasis. In this study we describe a novel protein, TmpL, involved in development and virulence in both plant and animal pathogenic fungi. In the absence of TmpL, dysregulation of oxidative stress homeostasis in both fungi caused developmental and virulence defects. Therefore, elucidating the role of TmpL presents an opportunity to uncover a common pathogenicity mechanism employed by both plant and animal pathogens and to develop efficient and novel therapeutics for both plant and animal fungal disease. Our findings provide new insights into mechanisms underlying the complex web of interactions between ROS and cell differentiation and the involvement of ROS for both plant and animal fungal pathogenesis.
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Affiliation(s)
- Kwang-Hyung Kim
- Virginia Bioinformatics Institute and Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Sven D. Willger
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana, United States of America
| | - Sang-Wook Park
- Virginia Bioinformatics Institute and Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Srisombat Puttikamonkul
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana, United States of America
| | - Nora Grahl
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana, United States of America
| | - Yangrae Cho
- Department of Plant and Environmental Protection Sciences, University of Hawaii, Honolulu, Hawaii, United States of America
| | - Biswarup Mukhopadhyay
- Virginia Bioinformatics Institute and Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Robert A. Cramer
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana, United States of America
- * E-mail: (RAC); (CBL)
| | - Christopher B. Lawrence
- Virginia Bioinformatics Institute and Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * E-mail: (RAC); (CBL)
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Shinozaki M, Okubo Y, Nakayama H, Mitsuda A, Ide T, Yamagata Murayama S, Shibuya K. Application of in situ hybridization to tissue sections for identification of molds causing invasive fungal infection. ACTA ACUST UNITED AC 2009; 50:75-83. [PMID: 19430181 DOI: 10.3314/jjmm.50.075] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The present article describes our studies to know the usefulness of in situ hybridization (ISH) to identify various kinds of mold observed in tissue sections and / or cytological preparations from the lesions of patients with invasive fungal infection. To establish the precise procedure for ISH in formalin-fixed and paraffin-embedded sections, various pretreatments were attempted. The condition finally chosen is written here providing a favorable outcome regarding to both intensity and specificity of signals on outline of molds observed in the tissue sections when specimens were treated with both heat and proteinase K and, solutions were adjusted to higher pH value.Therefore, usefulness of promising probes, two each DNA and peptide nucleic acid (PNA) were verified with a favorable pretreatment condition, using lungs of mice experimentally infected and / or those obtained from autopsies with invasive mold infection. As the result, DNA probes targeting alkaline proteinase (ALP) gene and retrotransposon Afut-1 gene of Aspergillus fumigatus showed specific signal intensity for the Aspergillus species and A. fumigatus, respectively. PNA probes for Candida albicans and the Fusarium species also showed satisfactory specificity. We wish to emphasize that ISH can be a valuable tool to identify medically important molds in formalin-fixed and paraffin-embedded tissue sections or cytological preparations.
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Affiliation(s)
- Minoru Shinozaki
- Department of Surgical Pathology, Toho University School of Medicine, 6-11-1 Omori-Nishi, Ota-Ku, Tokyo, Japan
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Magnani T, Soriani FM, Martins VDP, Policarpo ACDF, Sorgi CA, Faccioli LH, Curti C, Uyemura SA. Silencing of mitochondrial alternative oxidase gene of Aspergillus fumigatus enhances reactive oxygen species production and killing of the fungus by macrophages. J Bioenerg Biomembr 2009; 40:631-6. [PMID: 19148712 DOI: 10.1007/s10863-008-9191-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 11/24/2008] [Indexed: 01/27/2023]
Abstract
We previously demonstrated that conidia from Aspergillus fumigatus incubated with menadione and paraquat increases activity and expression of cyanide-insensitive alternative oxidase (AOX). Here, we employed the RNA silencing technique in A. fumigatus using the vector pALB1/aoxAf in order to down-regulate the aox gene. Positive transformants for aox gene silencing of A. fumigatus were more susceptible both to an imposed in vitro oxidative stress condition and to macrophages killing, suggesting that AOX is required for the A. fumigatus pathogenicity, mainly for the survival of the fungus conidia during host infection and resistance to reactive oxygen species generated by macrophages.
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Affiliation(s)
- Taisa Magnani
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café, s/n, 14040-903, Ribeirão Preto, SP, Brazil
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35
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Pasqualotto AC. Differences in pathogenicity and clinical syndromes due to Aspergillus fumigatus and Aspergillus flavus. Med Mycol 2008; 47 Suppl 1:S261-70. [PMID: 18654921 DOI: 10.1080/13693780802247702] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Most of the information available about Aspergillus infections has originated from the study of A. fumigatus, the most frequent species in the genus. This review aims to compare the pathogenicity and clinical aspects of Aspergillosis caused by A. fumigatus an A. flavus. Experimental data suggests that A. flavus is more virulent than A. fumigatus. However, these were mostly models of disseminated Aspergillus infection which do not properly mimic the physiopathology of invasive aspergillosis, a condition that is usually acquired by inhalation. In addition, no conclusive virulence factor has been identified for Aspergillus species. A. flavus is a common cause of fungal sinusitis and cutaneous infections. Chronic conditions such as chronic cavitary pulmonary aspergillosis and sinuses fungal balls have rarely been associated with A. flavus. The bigger size of A. flavus spores, in comparison to those of A. fumigatus spores, may favour their deposit in the upper respiratory tract. Differences between these species justify the need for a better understanding of A. flavus infections.
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Affiliation(s)
- Alessandro C Pasqualotto
- Infection Control Department at Santa Casa Complexo Hospitalar, Porto Alegre, and Post-Graduation Program in Pulmonary Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
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Sutay Kocabas D, Bakir U, Phillips SEV, McPherson MJ, Ogel ZB. Purification, characterization, and identification of a novel bifunctional catalase-phenol oxidase from Scytalidium thermophilum. Appl Microbiol Biotechnol 2008; 79:407-15. [PMID: 18369615 DOI: 10.1007/s00253-008-1437-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 02/26/2008] [Accepted: 02/26/2008] [Indexed: 11/27/2022]
Abstract
A novel bifunctional catalase with an additional phenol oxidase activity was isolated from a thermophilic fungus, Scytalidium thermophilum. This extracellular enzyme was purified ca. 10-fold with 46% yield and was biochemically characterized. The enzyme contains heme and has a molecular weight of 320 kDa with four 80 kDa subunits and an isoelectric point of 5.0. Catalase and phenol oxidase activities were most stable at pH 7.0. The activation energies of catalase and phenol oxidase activities of the enzyme were found to be 2.7 +/- 0.2 and 10.1 +/- 0.4 kcal/mol, respectively. The pure enzyme can oxidize o-diphenols such as catechol, caffeic acid, and L-DOPA in the absence of hydrogen peroxide and the highest oxidase activity is observed against catechol. No activity is detected against tyrosine and common laccase substrates such as ABTS and syringaldazine with the exception of weak activity with p-hydroquinone. Common catechol oxidase inhibitors, salicylhydroxamic acid and p-coumaric acid, inhibit the oxidase activity. Catechol oxidation activity was also detected in three other catalases tested, from Aspergillus niger, human erythrocyte, and bovine liver, suggesting that this dual catalase-phenol oxidase activity may be a common feature of catalases.
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Affiliation(s)
- Didem Sutay Kocabas
- Chemical Engineering Department, Middle East Technical University, Ankara, Turkey
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Cooper CR, Vanittanakom N. Insights into the pathogenicity of Penicillium marneffei. Future Microbiol 2008; 3:43-55. [PMID: 18230033 DOI: 10.2217/17460913.3.1.43] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Penicillium marneffei is a significant pathogen of AIDS patients in Southeast Asia. This fungus is unique in that it is the only dimorphic member of the genus. Pathogenesis of P. marneffei requires the saprobic mold form to undergo a morphological change upon tissue invasion. The in vivo form of this fungus reproduces as a fission yeast that capably evades the host immune system. The processes that control these morphological changes, better termed as phase transition, can be replicated in vitro by incubation of the mold form at 37 degrees C. The unidentified molecular mechanisms regulating phase transition in this fungus are now being uncovered using modern methodologies and novel strategies. A better comprehension of these underlying regulatory pathways will provide insight into eukaryotic cellular development as well as the potential factors responsible for infections caused by P. marneffei and other fungi. Such knowledge may lead to better chemotherapeutic interventions of fungal diseases.
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Affiliation(s)
- Chester R Cooper
- Department of Biological Sciences, Youngstown State University, 1 University Plaza, Youngstown, OH 44555, USA.
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Deletion analysis of the catalase-encoding gene (catB) promoter from Aspergillus oryzae. Biosci Biotechnol Biochem 2008; 72:48-53. [PMID: 18175923 DOI: 10.1271/bbb.70321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The catalase-encoding gene (catB) is expressed strongly in Aspergillus oryzae. To identify the transcription regulatory elements involved in strong expression, we did promoter deletion analysis using beta-glucuronidase (GUS) as a reporter and an electrophoretic gel mobility shift assay (EMSA) systematically. The deletion 200-bp sequence from -1,000 to -800 in the 1,400-bp catB promoter caused a drastic decrease in GUS activity. In addition, EMSA implicated a 45-bp element from -1,000 to -956 containing cis-elements. According to detailed promoter deletion analysis, a region from -1,000 to -975, which contains putative heat shock element (HSE) and the CCAAT-box, was involved in strong expression.
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