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Wassano NS, da Silva GB, Reis AH, A Gerhardt J, Antoniel EP, Akiyama D, Rezende CP, Neves LX, Vasconcelos EJR, de Figueiredo FL, Almeida F, de Castro PA, Pinzan CF, Goldman GH, Paes Leme AF, Fill TP, Moretti NS, Damasio A. Sirtuin E deacetylase is required for full virulence of Aspergillus fumigatus. Commun Biol 2024; 7:704. [PMID: 38851817 PMCID: PMC11162503 DOI: 10.1038/s42003-024-06383-3] [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: 10/03/2023] [Accepted: 05/24/2024] [Indexed: 06/10/2024] Open
Abstract
Aspergillus fumigatus represents a public health problem due to the high mortality rate in immunosuppressed patients and the emergence of antifungal-resistant isolates. Protein acetylation is a crucial post-translational modification that controls gene expression and biological processes. The strategic manipulation of enzymes involved in protein acetylation has emerged as a promising therapeutic approach for addressing fungal infections. Sirtuins, NAD+-dependent lysine deacetylases, regulate protein acetylation and gene expression in eukaryotes. However, their role in the human pathogenic fungus A. fumigatus remains unclear. This study constructs six single knockout strains of A. fumigatus and a strain lacking all predicted sirtuins (SIRTKO). The mutant strains are viable under laboratory conditions, indicating that sirtuins are not essential genes. Phenotypic assays suggest sirtuins' involvement in cell wall integrity, secondary metabolite production, thermotolerance, and virulence. Deletion of sirE attenuates virulence in murine and Galleria mellonella infection models. The absence of SirE alters the acetylation status of proteins, including histones and non-histones, and triggers significant changes in the expression of genes associated with secondary metabolism, cell wall biosynthesis, and virulence factors. These findings encourage testing sirtuin inhibitors as potential therapeutic strategies to combat A. fumigatus infections or in combination therapy with available antifungals.
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Affiliation(s)
- Natália S Wassano
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
- National Institute of Science and Technology in Human Pathogenic Fungi, Ribeirão Preto, Brazil
| | - Gabriela B da Silva
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
- National Institute of Science and Technology in Human Pathogenic Fungi, Ribeirão Preto, Brazil
- Department of Microbiology, Immunology and Parasitology, Paulist School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Artur H Reis
- Department of Microbiology, Immunology and Parasitology, Paulist School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Jaqueline A Gerhardt
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Everton P Antoniel
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Daniel Akiyama
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), Campinas, Brazil
| | - Caroline P Rezende
- Department of Biochemistry and Immunology, Faculty of Medicine from Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Leandro X Neves
- Brazilian Bioscience National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | | | - Fernanda L de Figueiredo
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Faculty of Medicine from Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Patrícia A de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Camila F Pinzan
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gustavo H Goldman
- National Institute of Science and Technology in Human Pathogenic Fungi, Ribeirão Preto, Brazil
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Adriana F Paes Leme
- Brazilian Bioscience National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Taicia P Fill
- National Institute of Science and Technology in Human Pathogenic Fungi, Ribeirão Preto, Brazil
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), Campinas, Brazil
| | - Nilmar S Moretti
- Department of Microbiology, Immunology and Parasitology, Paulist School of Medicine, Federal University of São Paulo, São Paulo, Brazil.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Canada.
- The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Canada.
| | - André Damasio
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil.
- National Institute of Science and Technology in Human Pathogenic Fungi, Ribeirão Preto, Brazil.
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2
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Wassano NS, da Silva GB, Reis AH, Gerhardt JA, Antoniel EP, Akiyama D, Rezende CP, Neves LX, Vasconcelos E, Figueiredo FL, Almeida F, de Castro PA, Pinzan CF, Goldman GH, Leme AFP, Fill TP, Moretti NS, Damasio A. Deacetylation by sirtuins is important for Aspergillus fumigatus pathogenesis and virulence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.558961. [PMID: 37808717 PMCID: PMC10557594 DOI: 10.1101/2023.09.25.558961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Protein acetylation is a crucial post-translational modification that controls gene expression and a variety of biological processes. Sirtuins, a prominent class of NAD + -dependent lysine deacetylases, serve as key regulators of protein acetylation and gene expression in eukaryotes. In this study, six single knockout strains of fungal pathogen Aspergillus fumigatus were constructed, in addition to a strain lacking all predicted sirtuins (SIRTKO). Phenotypic assays suggest that sirtuins are involved in cell wall integrity, secondary metabolite production, thermotolerance, and virulence. AfsirE deletion resulted in attenuation of virulence, as demonstrated in murine and Galleria infection models. The absence of AfSirE leads to altered acetylation status of proteins, including histones and non-histones, resulting in significant changes in the expression of genes associated with secondary metabolism, cell wall biosynthesis, and virulence factors. These findings encourage testing sirtuin inhibitors as potential therapeutic strategies to combat A. fumigatus infections or in combination therapy with available antifungals.
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Hokken MWJ, Coolen JPM, Steenbreker H, Zoll J, Baltussen TJH, Verweij PE, Melchers WJG. The Transcriptome Response to Azole Compounds in Aspergillus fumigatus Shows Differential Gene Expression across Pathways Essential for Azole Resistance and Cell Survival. J Fungi (Basel) 2023; 9:807. [PMID: 37623579 PMCID: PMC10455693 DOI: 10.3390/jof9080807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/26/2023] Open
Abstract
The opportunistic pathogen Aspergillus fumigatus is found on all continents and thrives in soil and agricultural environments. Its ability to readily adapt to novel environments and to produce billions of spores led to the spread of azole-resistant A. fumigatus across the globe, posing a threat to many immunocompromised patients, including critically ill patients with severe influenza or COVID-19. In our study, we sought to compare the adaptational response to azoles from A. fumigatus isolates that differ in azole susceptibility and genetic background. To gain more insight into how short-term adaptation to stressful azole compounds is managed through gene expression, we conducted an RNA-sequencing study on the response of A. fumigatus to itraconazole and the newest clinically approved azole, isavuconazole. We observed many similarities in ergosterol biosynthesis up-regulation across isolates, with the exception of the pan-azole-resistant isolate, which showed very little differential regulation in comparison to other isolates. Additionally, we found differential regulation of membrane efflux transporters, secondary metabolites, iron metabolism, and various stress response and cell signaling mechanisms.
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Affiliation(s)
- Margriet W. J. Hokken
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Jordy P. M. Coolen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Hilbert Steenbreker
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
| | - Jan Zoll
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Tim J. H. Baltussen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
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Bauer K, Rafael B, Vágó B, Kiss-Vetráb S, Molnár A, Szebenyi C, Varga M, Szekeres A, Vágvölgyi C, Papp T, Nagy G. Characterization of the Sterol 24-C-Methyltransferase Genes Reveals a Network of Alternative Sterol Biosynthetic Pathways in Mucor lusitanicus. Microbiol Spectr 2023; 11:e0031523. [PMID: 37036336 PMCID: PMC10269636 DOI: 10.1128/spectrum.00315-23] [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: 01/20/2023] [Accepted: 03/18/2023] [Indexed: 04/11/2023] Open
Abstract
Certain members of the order Mucorales can cause a life-threatening, often-fatal systemic infection called mucormycosis. Mucormycosis has a high mortality rate, which can reach 96 to 100% depending on the underlying condition of the patient. Mucorales species are intrinsically resistant to most antifungal agents, such as most of the azoles, which makes mucormycosis treatment challenging. The main target of azoles is the lanosterol 14α-demethylase (Erg11), which is responsible for an essential step in the biosynthesis of ergosterol, the main sterol component of the fungal membrane. Mutations in the erg11 gene can be associated with azole resistance; however, resistance can also be mediated by loss of function or mutation of other ergosterol biosynthetic enzymes, such as the sterol 24-C-methyltransferase (Erg6). The genome of Mucor lusitanicus encodes three putative erg6 genes (i.e., erg6a, erg6b, and erg6c). In this study, the role of erg6 genes in azole resistance of Mucor was analyzed by generating and analyzing knockout mutants constructed using the CRISPR-Cas9 technique. Susceptibility testing of the mutants suggested that one of the three genes, erg6b, plays a crucial role in the azole resistance of Mucor. The sterol composition of erg6b knockout mutants was significantly altered compared to that of the original strain, and it revealed the presence of at least four alternative sterol biosynthesis pathways leading to formation of ergosterol and other alternative, nontoxic sterol products. Dynamic operation of these pathways and the switching of biosynthesis from one to the other in response to azole treatment could significantly contribute to avoiding the effects of azoles by these fungi. IMPORTANCE The fungal membrane contains ergosterol instead of cholesterol, which offers a specific point of attack for the defense against pathogenic fungi. Indeed, most antifungal agents target ergosterol or its biosynthesis. Mucormycoses-causing fungi are resistant to most antifungal agents, including most of the azoles. For this reason, the drugs of choice to treat such infections are limited. The exploration of ergosterol biosynthesis is therefore of fundamental importance to understand the azole resistance of mucormycosis-causing fungi and to develop possible new control strategies. Characterization of sterol 24-C-methyltransferase demonstrated its role in the azole resistance and virulence of M. lusitanicus. Moreover, our experiments suggest that there are at least four alternative pathways for the biosynthesis of sterols in Mucor. Switching between pathways may contribute to the maintenance of azole resistance.
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Affiliation(s)
- Kitti Bauer
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Bence Rafael
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Bernadett Vágó
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Sándor Kiss-Vetráb
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Anna Molnár
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Csilla Szebenyi
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Mónika Varga
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - András Szekeres
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Csaba Vágvölgyi
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Tamás Papp
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Gábor Nagy
- Department of Microbiology, University of Szeged, Szeged, Hungary
- ELKH-SZTE Fungal Pathomechanisms Research Group, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
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Víglaš J, Olejníková P. Antifungal azoles trigger a xenobiotic detoxification pathway and chitin synthesis in Neurospora crassa. Res Microbiol 2023:104055. [PMID: 36963554 DOI: 10.1016/j.resmic.2023.104055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 02/15/2023] [Accepted: 03/15/2023] [Indexed: 03/26/2023]
Abstract
The presence of antifungal drugs is prompting the fungal microorganisms to react by mechanisms broader than the resistance. The fungi evolved mechanisms, by which they respond to various stress conditions, including the presence of antifungal compounds. In this work, we studied the response of model filamentous fungus Neurospora crassa to azole antifungals in the broader context of the adaptation mechanisms. We demonstrated the increase in expression of filamentous fungi-specific genes encoding cytochrome enzymes of CYP65 clan and plasma membrane-localized ABCC transporters. Azoles appear not to conjugate with glutathione. Surprisingly, the azoles caused changes in the hyphae organization and the amount of chitin in cell wall by the same manner that was thought to be echinocandin-specific. The response to individual azoles appeared to be influenced by the structure of azole compound (prochloraz - main outlier). Taken together, these findings demonstrate the importance of study of stress response mechanisms, specifically in filamentous fungi. Many aspects of the reaction within azoles seem to be similar, though specificities are occurring.
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Affiliation(s)
- Ján Víglaš
- Institute of Biochemistry and Microbiology, Faculty of Food and Chemical Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovakia.
| | - Petra Olejníková
- Institute of Biochemistry and Microbiology, Faculty of Food and Chemical Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovakia.
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Song G, Du S, Sun H, Liang Q, Wang H, Yan M, Zhang J. Antifungal mechanism of (E)-2-hexenal against Botrytis cinerea growth revealed by transcriptome analysis. Front Microbiol 2022; 13:951751. [PMID: 36071976 PMCID: PMC9444101 DOI: 10.3389/fmicb.2022.951751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022] Open
Abstract
Gray mold caused by Botrytis cinerea, a necrotrophic plant pathogen, is one of the most damaging diseases of tomato, resulting in both pre- and post-harvest losses. (E)-2-Hexenal dose-dependently inhibited the mycelial growth of B. cinerea, and caused distortion of mycelia and loss of the cytoplasm content, thus altering the morphology of B. cinerea hyphae. To understand molecular processes in response to (E)-2-hexenal, transcriptome sequencing was carried out using RNA-Seq technology. RNA-Seq results revealed that a total of 3,893 genes were differentially expressed in B. cinerea samples treated with (E)-2-hexenal fumigation. Among these genes, 1,949 were upregulated and 1,944 were downregulated. Moreover, further analysis results showed 2,113 unigenes were mapped onto 259 pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG). Moreover, (E)-2-hexenal stress affected the expression of genes involved in the pathways of cell wall, cell membrane, and energy metabolism. KEGG pathway analysis showed that the terpenoid backbone biosynthesis and steroid biosynthesis were the most enriched in ergosterol biosynthetic process transcriptome data. Particularly, (E)-2-hexenal fumigation had influenced ergosterol biosynthetic gene expression levels (e.g., ERG1, ERG3, ERG4, ERG7, ERG12, ERG13, ERG24, ERG25, ERG26, and ERG27), which were in good agreement with the experimental measurement results, and the ergosterol content decreased. Collectively, the results of this study increase our current understanding of (E)-2-hexenal inhibition mechanisms in B. cinerea and provide relevant information on postharvest shelf life extension and preservation of fruits and vegetables.
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Affiliation(s)
- Ge Song
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan, China
| | - Shenglong Du
- Department of Chemical Engineering, Xiangtan University, Xiangtan, China
| | - Helong Sun
- Department of Chemical Engineering, Xiangtan University, Xiangtan, China
| | - Quanwu Liang
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan, China
| | - Haihua Wang
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan, China
| | - Mingli Yan
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan, China
| | - Jihong Zhang
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan, China
- *Correspondence: Jihong Zhang,
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Deletion of cox7c Results in Pan-Azole Resistance in Aspergillus fumigatus. Antimicrob Agents Chemother 2022; 66:e0015122. [PMID: 35647650 PMCID: PMC9211413 DOI: 10.1128/aac.00151-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Aspergillus fumigatus, the most prevalent resistance to azoles results from mutational modifications of the azole target protein Cyp51A, but there are non-cyp51A mutants resistant to azoles, and the mechanisms underlying the resistance of these strains remain to be explored. Here, we identified a novel cytochrome c oxidase, cox7c (W56*), nonsense mutation in the laboratory and found that it caused reduced colony growth and resistance to multiantifungal agents. Meanwhile, we revealed that cold storage is responsible for increased tolerance of conidia to itraconazole (ITC) stress, which further advances azole-resistant mutations (cryopreservation→ITC tolerance→azole resistance). The deletion or mutation of cox7c results explicitly in resistance to antifungal-targeting enzymes, including triazoles, polyenes, and allylamines, required for ergosterol synthesis, or resistance to fungal ergosterol. A high-performance liquid chromatography (HPLC) assay showed that the cox7c knockout strain decreased intracellular itraconazole concentration. In addition, the lack of Cox7c resulted in the accumulation of intracellular heme B. We validated that an endogenous increase in, or the exogenous addition of, heme B was capable of eliciting azole resistance, which was in good accordance with the phenotypic resistance analysis of cox7c mutants. Furthermore, RNA sequencing verified the elevated transcriptional expression levels of multidrug transport genes. Additionally, lower itraconazole-induced reactive oxygen species generation in mycelia of a cox7c-deletion strain suggested that this reduction may, in part, contribute to drug resistance. These findings increase our understanding of how A. fumigatus’s direct responses to azoles promote fungal survival in the environment and address genetic mutations that arise from patients or environments.
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Subroto E, van Neer J, Valdes I, de Cock H. Growth of Aspergillus fumigatus in Biofilms in Comparison to Candida albicans. J Fungi (Basel) 2022; 8:48. [PMID: 35049988 PMCID: PMC8779434 DOI: 10.3390/jof8010048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 12/18/2022] Open
Abstract
Biofilm formation during infections with the opportunistic pathogen Aspergillus fumigatus can be very problematic in clinical settings, since it provides the fungal cells with a protective environment. Resistance against drug treatments, immune recognition as well as adaptation to the host environment allows fungal survival in the host. The exact molecular mechanisms behind most processes in the formation of biofilms are unclear. In general, the formation of biofilms can be categorized roughly in a few stages; adhesion, conidial germination and development of hyphae, biofilm maturation and cell dispersion. Fungi in biofilms can adapt to the in-host environment. These adaptations can occur on a level of phenotypic plasticity via gene regulation. However, also more substantial genetic changes of the genome can result in increased resistance and adaptation in the host, enhancing the survival chances of fungi in biofilms. Most research has focused on the development of biofilms. However, to tackle developing microbial resistance and adaptation in biofilms, more insight in mechanisms behind genetic adaptations is required to predict which defense mechanisms can be expected. This can be helpful in the development of novel and more targeted antifungal treatments to combat fungal infections.
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Affiliation(s)
| | | | | | - Hans de Cock
- Molecular Microbiology Laboratory, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (E.S.); (J.v.N.); (I.V.)
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Gonzalez-Jimenez I, Lucio J, Roldan A, Alcazar-Fuoli L, Mellado E. Are Point Mutations in HMG-CoA Reductases (Hmg1 and Hmg2) a Step towards Azole Resistance in Aspergillus fumigatus? Molecules 2021; 26:5975. [PMID: 34641518 PMCID: PMC8512156 DOI: 10.3390/molecules26195975] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/16/2022] Open
Abstract
Invasive aspergillosis, mainly caused by Aspergillus fumigatus, can lead to severe clinical outcomes in immunocompromised individuals. Antifungal treatment, based on the use of azoles, is crucial to increase survival rates. However, the recent emergence of azole-resistant A. fumigatus isolates is affecting the efficacy of the clinical therapy and lowering the success rate of azole strategies against aspergillosis. Azole resistance mechanisms described to date are mainly associated with mutations in the azole target gene cyp51A that entail structural changes in Cyp51A or overexpression of the gene. However, strains lacking cyp51A modifications but resistant to clinical azoles have recently been detected. Some genes have been proposed as new players in azole resistance. In this study, the gene hmg1, recently related to azole resistance, and its paralogue hmg2 were studied in a collection of fifteen azole-resistant strains without cyp51A modifications. Both genes encode HMG-CoA reductases and are involved in the ergosterol biosynthesis. Several mutations located in the sterol sensing domain (SSD) of Hmg1 (D242Y, G307D/S, P309L, K319Q, Y368H, F390L and I412T) and Hmg2 (I235S, V303A, I312S, I360F and V397C) were detected. The role of these mutations in conferring azole resistance is discussed in this work.
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Affiliation(s)
- Irene Gonzalez-Jimenez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
| | - Jose Lucio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
| | - Alejandra Roldan
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
| | - Laura Alcazar-Fuoli
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
- Spanish Network for Research in Infectious Diseases (REIPI RD16/CIII/0004/0003), ISCIII, 28220 Majadahonda, Madrid, Spain
| | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), 28220 Majadahonda, Madrid, Spain; (I.G.-J.); (J.L.); (A.R.); (L.A.-F.)
- Spanish Network for Research in Infectious Diseases (REIPI RD16/CIII/0004/0003), ISCIII, 28220 Majadahonda, Madrid, Spain
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Arastehfar A, Carvalho A, Houbraken J, Lombardi L, Garcia-Rubio R, Jenks J, Rivero-Menendez O, Aljohani R, Jacobsen I, Berman J, Osherov N, Hedayati M, Ilkit M, Armstrong-James D, Gabaldón T, Meletiadis J, Kostrzewa M, Pan W, Lass-Flörl C, Perlin D, Hoenigl M. Aspergillus fumigatus and aspergillosis: From basics to clinics. Stud Mycol 2021; 100:100115. [PMID: 34035866 PMCID: PMC8131930 DOI: 10.1016/j.simyco.2021.100115] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.
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Affiliation(s)
- A. Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - A. Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - J. Houbraken
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - L. Lombardi
- UCD Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - R. Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - J.D. Jenks
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, CA, 92093, USA
| | - O. Rivero-Menendez
- Medical Mycology Reference Laboratory, National Center for Microbiology, Instituto de Salud Carlos III, Madrid, 28222, Spain
| | - R. Aljohani
- Department of Infectious Diseases, Imperial College London, London, UK
| | - I.D. Jacobsen
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - J. Berman
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
| | - N. Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, 69978, Israel
| | - M.T. Hedayati
- Invasive Fungi Research Center/Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - M. Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, Çukurova University, 01330, Adana, Turkey
| | | | - T. Gabaldón
- Life Sciences Programme, Supercomputing Center (BSC-CNS), Jordi Girona, Barcelona, 08034, Spain
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - J. Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | - W. Pan
- Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - C. Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - D.S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - M. Hoenigl
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, 8036, Graz, Austria
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, San Diego, CA 92093, USA
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11
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Abstract
Invasive fungal disease continues to be a cause of significant life-threatening morbidity and mortality in humans, particularly in those with a diminished immune system, such as with haematological malignancies. The mainstay of treating such life-threatening fungal infection has been antifungal drugs, including azoles, echinocandins and macrocyclic polyenes. However, like antibiotic resistance, antifungal resistance is beginning to emerge, potentially jeopardizing the effectiveness of these molecules in the treatment of fungal disease. One strategy to avoid this is the development of fungal vaccines. However, the inability to provoke a sufficient immune response in the most vulnerable immunocompromised groups has hindered translation from bench to bedside. This review will assess the latest available data and will investigate potential Aspergillus antigens and feasible vaccine techniques, particularly for vaccination of high-risk groups, including immunocompromised and immunosuppressed populations.
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Affiliation(s)
- H T Pattison
- School of Medicine, Dentistry and Biomedical Sciences, the Wellcome-Wolfson Institute for Experimental Medicine, Queen's University, Belfast, Northern Ireland, UK
| | - B C Millar
- School of Medicine, Dentistry and Biomedical Sciences, the Wellcome-Wolfson Institute for Experimental Medicine, Queen's University, Belfast, Northern Ireland, UK.,Laboratory for Disinfection and Pathogen Elimination Studies, Northern Ireland Public Health Laboratory, Nightingale (Belfast City) Hospital, Belfast, Northern Ireland, UK
| | - J E Moore
- School of Medicine, Dentistry and Biomedical Sciences, the Wellcome-Wolfson Institute for Experimental Medicine, Queen's University, Belfast, Northern Ireland, UK.,Laboratory for Disinfection and Pathogen Elimination Studies, Northern Ireland Public Health Laboratory, Nightingale (Belfast City) Hospital, Belfast, Northern Ireland, UK
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12
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Pedezzi R, de Biagi Junior CAO, de Freitas MCC, da Rosa-Garzon NG, Cabral H. Transcriptomic studies on Purpureocillium lilacinum reveal molecular mechanisms of response to fluconazole and itraconazole. Braz J Microbiol 2021; 52:491-501. [PMID: 33651333 PMCID: PMC8105456 DOI: 10.1007/s42770-021-00459-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 02/23/2021] [Indexed: 11/25/2022] Open
Abstract
Filamentous fungus Purpureocillium lilacinum is an emerging pathogen that infects immunocompromised and immunocompetent individuals and is resistant to several azole molecules. Although azole resistance mechanisms are well studied in Aspergillus sp. and Candida sp., there are no studies to date reporting P. lilacinum molecular response to these molecules. The aim of this study was to describe P. lilacinum molecular mechanisms involved in antifungal response against fluconazole and itraconazole. Transcriptomic analyses showed that gene expression modulation takes place when P. lilacinum is challenged for 12 h with fluconazole (64 μg/mL) or itraconazole (16 μg/mL). The antifungals acted on the ergosterol biosynthesis pathway, and two homologous genes coding for cytochrome P450 51 enzymes were upregulated. Genes coding for efflux pumps, such as the major facilitator superfamily transporter, also displayed increased expression in the treated samples. We propose that P. lilacinum develops antifungal responses by raising the expression levels of cytochrome P450 enzymes and efflux pumps. Such modulation could confer P. lilacinum high levels of target enzymes and could lead to the constant withdrawal of antifungals, which would force an increase in the administration of antifungal medications to achieve fungal morbidity or mortality. The findings in this work could aid in the decision-making for treatment strategies in cases of P. lilacinum infection.
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Affiliation(s)
- Rafael Pedezzi
- Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903, Brazil
| | - Carlos Alberto Oliveira de Biagi Junior
- Department of Genetics, Ribeirão Preto Medical School, National Institute of Science and Technology in Stem Cell and Cell Therapy, University of São Paulo, Ribeirão Preto, 14049-900, Brazil
| | - Marcela Cristina Corrêa de Freitas
- Department of Medical Clinic, Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, 14049-900, Brazil
| | - Nathália Gonsales da Rosa-Garzon
- Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903, Brazil
| | - Hamilton Cabral
- Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903, Brazil.
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13
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Genetic and Phenotypic Characterization of in-Host Developed Azole-Resistant Aspergillus flavus Isolates. J Fungi (Basel) 2021; 7:jof7030164. [PMID: 33668871 PMCID: PMC7996152 DOI: 10.3390/jof7030164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/21/2021] [Accepted: 02/22/2021] [Indexed: 11/17/2022] Open
Abstract
Aspergillus flavus is a pathogenic fungal species that can cause pulmonary aspergillosis, and triazole compounds are used for the treatment of these infections. Prolonged exposure to azoles may select for compensatory mutations in the A. flavus genome, resulting in azole resistance. Here, we characterize a series of 11 isogenic A. flavus strains isolated from a patient with pulmonary aspergillosis. Over a period of three months, the initially azole-susceptible strain developed itraconazole and voriconazole resistance. Short tandem repeat analysis and whole-genome sequencing revealed the high genetic relatedness of all isolates, indicating an infection with one single isolate. In contrast, the isolates were macroscopically highly diverse, suggesting an adaptation to the environment due to (epi)genetic changes. The whole-genome sequencing of susceptible and azole-resistant strains showed a number of mutations that might be associated with azole resistance. The majority of resistant strains contain a Y119F mutation in the Cyp51A gene, which corresponds to the Y121F mutation found in A. fumigatus. One azole-resistant strain demonstrated a divergent set of mutations, including a V99A mutation in a major facilitator superfamily (MSF) multidrug transporter (AFLA 083950).
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14
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van der Torre MH, Shen H, Rautemaa-Richardson R, Richardson MD, Novak-Frazer L. Molecular Epidemiology of Aspergillus fumigatus in Chronic Pulmonary Aspergillosis Patients. J Fungi (Basel) 2021; 7:jof7020152. [PMID: 33672698 PMCID: PMC7924367 DOI: 10.3390/jof7020152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 12/17/2022] Open
Abstract
Molecular fungal genotyping techniques developed and employed for epidemiological studies have understandably concentrated on establishing the genetic diversity of Aspergillus fumigatus in invasive aspergillosis due to its severity, the urgency for treatment, and the need to demonstrate possible sources. Some early studies suggested that these strains were phenotypically, if not genotypically, different from others. However, with improved discrimination and evaluations, incorporating environmental as well as clinical isolates from other Aspergillus conditions (e.g., chronic pulmonary aspergillosis and cystic fibrosis), this premise is no longer upheld. Moreover, with the onset of increased global triazole resistance, there has been a concerted effort to incorporate resistance profiling into genotyping studies and the realisation that the wider population of non-immunocompromised aspergillosis patients are at risk. This review summarises the developments in molecular genotyping studies that incorporate resistance profiling with attention to chronic pulmonary aspergillosis and an example of our UK experience.
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Affiliation(s)
- Mireille H. van der Torre
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
| | - Hongwei Shen
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
- Department of Infectious Diseases, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
| | - Malcolm D. Richardson
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
| | - Lilyann Novak-Frazer
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
- Correspondence: ; Tel.: +44-161-2915856
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15
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Víglaš J, Olejníková P. An update on ABC transporters of filamentous fungi - from physiological substrates to xenobiotics. Microbiol Res 2021; 246:126684. [PMID: 33529790 DOI: 10.1016/j.micres.2020.126684] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/13/2020] [Accepted: 12/18/2020] [Indexed: 02/02/2023]
Abstract
The superfamily of ATP-binding cassette (ABC) transporters is a large family of proteins with a wide substrate repertoire and range of functions. The main role of these proteins is in the transportation of different molecules across biological membranes. Due to the broad range of substrates, ABC transporters can transport not only natural metabolites but also various xenobiotics, including antifungal compounds, which makes some ABC transporters key players in antifungal resistance. Alternatively, ABC proteins without transport function seem to be essential for fungal cell viability. In this work, we review the individual subfamilies of ABC transporters in filamentous fungi regarding physiological substrates, clinical and agricultural significance. Subfamilies are defined using well-studied transporters in yeast, which may help to clarify their role in filamentous fungi.
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Affiliation(s)
- Ján Víglaš
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237, Bratislava, Slovakia.
| | - Petra Olejníková
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237, Bratislava, Slovakia.
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16
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Zhao S, Ge W, Watanabe A, Fortwendel JR, Gibbons JG. Genome-Wide Association for Itraconazole Sensitivity in Non-resistant Clinical Isolates of Aspergillus fumigatus. FRONTIERS IN FUNGAL BIOLOGY 2021; 1:617338. [PMID: 37743877 PMCID: PMC10512406 DOI: 10.3389/ffunb.2020.617338] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/15/2020] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is a potentially lethal opportunistic pathogen that infects over ~200,000 people and causes ~100,000 deaths per year globally. Treating A. fumigatus infections is particularly challenging because of the recent emergence of azole-resistance. The majority of studies focusing on the molecular mechanisms underlying azole resistance have examined azole-resistant isolates. However, isolates that are susceptible to azoles also display variation in their sensitivity, presenting a unique opportunity to identify genes contributing to azole sensitivity. Here, we used genome-wide association (GWA) analysis to identify loci involved in azole sensitivity by analyzing the association between 68,853 SNPs and itraconazole (ITCZ) minimum inhibitory concentration (MIC) in 76 clinical isolates of A. fumigatus from Japan. Population structure analysis suggests the presence of four distinct populations, with ITCZ MICs distributed relatively evenly across populations. We independently conducted GWA when treating ITCZ MIC as a quantitative trait and a binary trait, and identified two SNPs with strong associations in both analyses. These SNPs fell within the coding regions of Afu2g02220 and Afu2g02140. We functionally validated Afu2g02220 by knocking it out using a CRISPR/Cas9 approach, because orthologs of this gene are involved in sterol modification and ITCZ targets the ergosterol biosynthesis pathway. Knockout strains displayed no difference in growth compared to the parent strain in minimal media, yet a minor but consistent inhibition of growth in the presence of 0.15 μg/ml ITCZ. Our results suggest that GWA paired with efficient gene deletion is a powerful and unbiased strategy for identifying the genetic basis of complex traits in A. fumigatus.
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Affiliation(s)
- Shu Zhao
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Wenbo Ge
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Akira Watanabe
- Division of Clinical Research, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, United States
| | - John G. Gibbons
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
- Organismic and Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
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17
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Gonzalez-Jimenez I, Lucio J, Amich J, Cuesta I, Sanchez Arroyo R, Alcazar-Fuoli L, Mellado E. A Cyp51B Mutation Contributes to Azole Resistance in Aspergillus fumigatus. J Fungi (Basel) 2020; 6:jof6040315. [PMID: 33255951 PMCID: PMC7712412 DOI: 10.3390/jof6040315] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
The emergence and spread of Aspergillus fumigatus azole resistance has been acknowledged worldwide. The main problem of azole resistance is the limited therapeutic options for patients suffering aspergillosis. Azole resistance mechanisms have been mostly linked to the enzyme Cyp51A, a target of azole drugs, with a wide variety of modifications responsible for the different resistance mechanisms described to date. However, there are increasing reports of A. fumigatus strains showing azole resistance without Cyp51A modifications, and thus, novel resistance mechanisms are being explored. Here, we characterized two isogenic A. fumigatus clinical strains isolated two years apart from the same patient. Both strains were resistant to clinical azoles but showed different azole resistance mechanisms. One strain (CM8940) harbored a previously described G54A mutation in Cyp51A while the other strain (CM9640) had a novel G457S mutation in Cyp51B, the other target of azoles. In addition, this second strain had a F390L mutation in Hmg1. CM9640 showed higher levels of gene expression of cyp51A, cyp51B and hmg1 than the CM8940 strain. The role of the novel mutation found in Cyp51B together with the contribution of a mutation in Hmg1 in azole resistance is discussed.
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Affiliation(s)
- Irene Gonzalez-Jimenez
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain; (I.G.-J.); (J.L.); (L.A.-F.)
| | - Jose Lucio
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain; (I.G.-J.); (J.L.); (L.A.-F.)
| | - Jorge Amich
- Manchester Fungal Infection Group (MFIG), Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester M13 9PL, UK;
| | - Isabel Cuesta
- Bioinformatics Unit, Common Scientific Technical Units, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain;
| | | | - Laura Alcazar-Fuoli
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain; (I.G.-J.); (J.L.); (L.A.-F.)
- Spanish Network for Research in Infectious Diseases (REIPI RD16/CIII/0004/0003), Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain
| | - Emilia Mellado
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain; (I.G.-J.); (J.L.); (L.A.-F.)
- Spanish Network for Research in Infectious Diseases (REIPI RD16/CIII/0004/0003), Instituto de Salud Carlos III (ISCIII), Majadahonda, 28222 Madrid, Spain
- Correspondence:
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18
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Víglaš J, Olejníková P. Signalling mechanisms involved in stress response to antifungal drugs. Res Microbiol 2020; 172:103786. [PMID: 33038529 DOI: 10.1016/j.resmic.2020.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 01/28/2023]
Abstract
The emergence of antifungal resistance is a serious threat in the treatment of mycoses. The primary susceptible fungal cells may evolve a resistance after longer exposure to antifungal agents. The exposure itself causes stress condition, to which the fungus needs to adapt. This review provides detailed description of evolutionary conserved molecular mechanisms contributing to the adaptation response to stress caused by antifungal agents as well as their interconnection. The knowledge may help us to find new ways to delay the emergence of drug resistance as the same mechanisms are used regardless of what antifungal compound causes stress.
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Affiliation(s)
- Ján Víglaš
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237, Bratislava, Slovakia.
| | - Petra Olejníková
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237, Bratislava, Slovakia.
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19
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Chen P, Liu J, Zeng M, Sang H. Exploring the molecular mechanism of azole resistance in Aspergillus fumigatus. J Mycol Med 2020; 30:100915. [DOI: 10.1016/j.mycmed.2019.100915] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/24/2019] [Accepted: 11/24/2019] [Indexed: 12/20/2022]
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20
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Esquivel BD, Rybak JM, Barker KS, Fortwendel JR, Rogers PD, White TC. Characterization of the Efflux Capability and Substrate Specificity of Aspergillus fumigatus PDR5-like ABC Transporters Expressed in Saccharomyces cerevisiae. mBio 2020; 11:e00338-20. [PMID: 32209680 PMCID: PMC7157516 DOI: 10.1128/mbio.00338-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 12/27/2022] Open
Abstract
This research analyzed six Aspergillus fumigatus genes encoding putative efflux proteins for their roles as transporters. TheA. fumigatus genes abcA, abcC, abcF, abcG, abcH, and abcI were cloned into plasmids and overexpressed in a Saccharomyces cerevisiae strain in which the highly active endogenous ABC transporter gene PDR5 was deleted. The activity of each transporter was measured by efflux of rhodamine 6G and accumulation of alanine β-naphthylamide. The transporters AbcA, AbcC, and AbcF had the strongest efflux activities of these compounds. All of the strains with plasmid-expressed transporters had more efflux activity than did the PDR5-deleted background strain. We performed broth microdilution drug susceptibility testing and agar spot assays using an array of compounds and antifungal drugs to determine the transporter specificity and drug susceptibility of the strains. The transporters AbcC and AbcF showed the broadest range of substrate specificity, while AbcG and AbcH had the narrowest range of substrates. Strains expressing the AbcA, AbcC, AbcF, or AbcI transporter were more resistant to fluconazole than was the PDR5-deleted background strain. Strains expressing AbcC and AbcF were additionally more resistant to clotrimazole, itraconazole, ketoconazole, and posaconazole than was the background strain. Finally, we analyzed the expression levels of the genes by reverse transcription-quantitative PCR (RT-qPCR) in triazole-susceptible and -resistant A. fumigatus clinical isolates. All of these transporters are expressed at a measurable level, and transporter expression varied significantly between strains, demonstrating the high degree of phenotypic variation, plasticity, and divergence of which this species is capable.IMPORTANCE One mechanism behind drug resistance is altered export out of the cell. This work is a multifaceted analysis of membrane efflux transporters in the human fungal pathogen A. fumigatus Bioinformatics evidence infers that there is a relatively large number of genes in A. fumigatus that encode ABC efflux transporters. However, very few of these transporters have been directly characterized and analyzed for their potential role in drug resistance.Our objective was to determine if these undercharacterized proteins function as efflux transporters and then to better define whether their efflux substrates include antifungal drugs used to treat fungal infections. We chose six A. fumigatus potential plasma membrane ABC transporter genes for analysis and found that all six genes produced functional transporter proteins. We used two fungal systems to look for correlations between transporter function and drug resistance. These transporters have the potential to produce drug-resistant phenotypes in A. fumigatus Continued characterization of these and other transporters may assist in the development of efflux inhibitor drugs.
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Affiliation(s)
- Brooke D Esquivel
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Jeffrey M Rybak
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Katherine S Barker
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jarrod R Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - P David Rogers
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Theodore C White
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, USA
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21
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Hemp to limit diffusion of difenoconazole in vegetable garden soils. Heliyon 2019; 5:e02392. [PMID: 31517120 PMCID: PMC6731327 DOI: 10.1016/j.heliyon.2019.e02392] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/06/2019] [Accepted: 08/28/2019] [Indexed: 11/25/2022] Open
Abstract
Triazole molecules are used to manage invasive aspergillosis, a fungal infection mainly due to Aspergillus fumigatus. A. fumigatus is not a phytopathogen, but, as it is widespread in soils, triazole fungicides have an unintended impact on it, selecting resistant populations’ in environment. Thus, to maintain our ability to control fungal infections, whether in human health or agriculture, reduce the impact of the use of triazoles in the environment is important, notably limiting their diffusion in soils. Here we tested a hemp-based material as adsorbent to limit the spread of difenoconazole, a triazole fungicide, in vegetable soils. We studied the effects of contact time, material dose, difenoconazole concentration, and organic content of the soil using batch mode and percolation methods. Batch experiments showed that the material exhibited high adsorption capacities toward difenoconazole. Removal from the soil water increased from 46.6% using 0.35 g hemp per kg of soil to 77.0% using 1.75 g hemp per kg, for a contact time of 15 min and an initial difenoconazole concentration of 1.2 mg/L. For a contact time of 240 min, the removal was 93.5%. Percolation experiments showed that the quantity of difenoconazole removed was greater than the amount obtained by batch method: 41.9% of removal with only one passes of solution at a concentration of 12 mg/L is obtained through percolation technique whereas, with similar conditions, only 20% of removal is obtained by batch method, i.e. after 1 min of contact. The removal was strongly dependent on the number of passes: the values increased from 57.0% to 91.0% with increasing the number of passes from 1 to 15. Addition of hemp to soils allows to remove efficiently the difenoconazole fungicide from soil water. Hemp-based felt is a new and safe adsorbent that can be applied in agriculture to limit crop contamination.
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Fabri JHTM, Rocha MC, Malavazi I. Overview of the Interplay Between Cell Wall Integrity Signaling Pathways and Membrane Lipid Biosynthesis in Fungi: Perspectives for Aspergillus fumigatus. Curr Protein Pept Sci 2019; 21:265-283. [PMID: 31284857 DOI: 10.2174/1389203720666190705164203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/10/2019] [Accepted: 06/13/2019] [Indexed: 11/22/2022]
Abstract
The cell wall (CW) and plasma membrane are fundamental structures that define cell shape and support different cellular functions. In pathogenic fungi, such as Aspegillus fumigatus, they not only play structural roles but are also important for virulence and immune recognition. Both the CW and the plasma membrane remain as attractive drug targets to treat fungal infections, such as the Invasive Pulmonary Aspergillosis (IPA), a disease associated with high morbimortality in immunocompromised individuals. The low efficiency of echinocandins that target the fungal CW biosynthesis, the occurrence of environmental isolates resistant to azoles such as voriconazole and the known drawbacks associated with amphotericin toxicity foster the urgent need for fungal-specific drugable targets and/or more efficient combinatorial therapeutic strategies. Reverse genetic approaches in fungi unveil that perturbations of the CW also render cells with increased susceptibility to membrane disrupting agents and vice-versa. However, how the fungal cells simultaneously cope with perturbation in CW polysaccharides and cell membrane proteins to allow morphogenesis is scarcely known. Here, we focus on current information on how the main signaling pathways that maintain fungal cell wall integrity, such as the Cell Wall Integrity and the High Osmolarity Glycerol pathways, in different species often cross-talk to regulate the synthesis of molecules that comprise the plasma membrane, especially sphingolipids, ergosterol and phospholipids to promote functioning of both structures concomitantly and thus, cell viability. We propose that the conclusions drawn from other organisms are the foundations to point out experimental lines that can be endeavored in A. fumigatus.
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Affiliation(s)
| | - Marina C Rocha
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
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