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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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Smallwood D, Lockey RF, Kolliputi N. PANoptosis opens new treatment options for allergic bronchopulmonary aspergillosis. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. GLOBAL 2024; 3:100298. [PMID: 39170913 PMCID: PMC11338086 DOI: 10.1016/j.jacig.2024.100298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/23/2024] [Accepted: 04/05/2024] [Indexed: 08/23/2024]
Abstract
Background Allergic bronchopulmonary aspergillosis (ABPA) is a rare airway disorder primarily affecting patients with asthma and cystic fibrosis. Persistent airway inflammation brought on by Aspergillus fumigatus exacerbates the underlying condition and can cause significant respiratory damage. Treatments center on reducing inflammation with the use of corticosteroids and antifungals. PANoptosis is a new concept in the field of cell death and inflammation that posits the existence of cross talk and a master control system for the 3 programmed cell death (PCD) pathways, namely, apoptosis, pyroptosis, and necroptosis. This concept has revolutionized the understanding of PCD and opened new avenues for its exploration. Studies show that Aspergillus is one of the pathogens that is capable of activating PANoptosis via the Z-DNA binding protein 1 (ZBP1) pathway and plays an active role in the inflammation caused by this organism. Objective This article explores the nature of inflammation in ABPA and ways in which PCD could lead to novel treatment options. Method PubMed was used to review the literature surrounding Aspergillus infection-related inflammation and PANoptosis. Results There is evidence that apoptosis and pyroptosis protect against Aspergillus-induced inflammation, whereas necroptosis promotes inflammation. Conclusion Experimental medications, in particular, necroptosis inhibitors such as necrosulfonamide and necrostatin-1, should be studied for use in the treatment of ABPA.
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Affiliation(s)
- Dalan Smallwood
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa Fla
| | - Richard F. Lockey
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa Fla
| | - Narasaiah Kolliputi
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa Fla
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Ding JL, Feng MG, Ying SH. Two ferrous iron transporter-like proteins independently participate in asexual development under iron limitation and virulence in Beauveria bassiana. Fungal Genet Biol 2024; 173:103908. [PMID: 38857848 DOI: 10.1016/j.fgb.2024.103908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/02/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
Reductive assimilation pathway involves ferric reductase and ferrous iron transporter, which is integral for fungal iron acquisition. A family of ferric reductase-like proteins has been functionally characterized in the filamentous entomopathogenic fungus Beauveria bassiana. In this investigation, two ferrous iron transporter-like proteins (Ftr) were functionally annotated in B. bassiana. BbFtr1 and BbFtr2 displayed high similarity in structure and were associated with the plasma and nuclear membrane. Their losses had no negatively influence on fungal growth on various nutrients and development under the iron-replete condition. Single mutants of BbFTR1 and BbFTR2 displayed the iron-availability dependent developmental defects, and double mutant exhibited the significantly impaired developmental potential under the iron-limited conditions. In insect bioassay, the double mutant also showed the weaker virulence than either of two single disruption mutants. These results suggested that two ferrous iron transporter-like proteins function independently in fungal physiologies under the iron-deficient condition. Intriguingly, a bZIP transcription factor BbHapX was required for expression of BbFTR1 and BbFTR2 under iron-depleted conditions. This study enhances our understanding of the iron uptake system in the filamentous entomopathogenic fungi.
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Affiliation(s)
- Jin-Li Ding
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Gluck-Thaler E, Forsythe A, Puerner C, Stajich JE, Croll D, Cramer RA, Vogan AA. Giant transposons promote strain heterogeneity in a major fungal pathogen. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601215. [PMID: 38979181 PMCID: PMC11230402 DOI: 10.1101/2024.06.28.601215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Fungal infections are difficult to prevent and treat in large part due to heterogeneity in clinically relevant phenotypes. However, the genetic mechanisms driving pathogen variation remain poorly understood. Here, we determined the extent to which Starships -giant transposons capable of mobilizing numerous fungal genes-generate genetic and phenotypic variability in the human pathogen Aspergillus fumigatus . We analyzed 519 diverse strains, including 12 newly sequenced with long-read technology, to reveal 20 distinct Starships that generate genomic heterogeneity over timescales impacting experimental reproducibility. Starship -mobilized genes encode diverse functions, including biofilm-related virulence factors and biosynthetic gene clusters, and many are differentially expressed during infection and antifungal exposure in a strain-specific manner. These findings support a new model of fungal pathogenesis wherein Starships mediate variation in virulence-related gene content and expression. Together, our results demonstrate that Starships are a foundational mechanism generating disease-relevant genotypic and, in turn, phenotypic heterogeneity in a major human fungal pathogen.
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Curtis A, Dobes P, Marciniak J, Hurychova J, Hyrsl P, Kavanagh K. Characterization of Aspergillus fumigatus secretome during sublethal infection of Galleria mellonella larvae. J Med Microbiol 2024; 73:001844. [PMID: 38836745 PMCID: PMC11261830 DOI: 10.1099/jmm.0.001844] [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: 02/16/2024] [Accepted: 05/17/2024] [Indexed: 06/06/2024] Open
Abstract
Introduction. The fungal pathogen Aspergillus fumigatus can induce prolonged colonization of the lungs of susceptible patients, resulting in conditions such as allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis.Hypothesis. Analysis of the A. fumigatus secretome released during sub-lethal infection of G. mellonella larvae may give an insight into products released during prolonged human colonisation.Methodology. Galleria mellonella larvae were infected with A. fumigatus, and the metabolism of host carbohydrate and proteins and production of fungal virulence factors were analysed. Label-free qualitative proteomic analysis was performed to identify fungal proteins in larvae at 96 hours post-infection and also to identify changes in the Galleria proteome as a result of infection.Results. Infected larvae demonstrated increasing concentrations of gliotoxin and siderophore and displayed reduced amounts of haemolymph carbohydrate and protein. Fungal proteins (399) were detected by qualitative proteomic analysis in cell-free haemolymph at 96 hours and could be categorized into seven groups, including virulence (n = 25), stress response (n = 34), DNA repair and replication (n = 39), translation (n = 22), metabolism (n = 42), released intracellular (n = 28) and cellular development and cell cycle (n = 53). Analysis of the Gallerial proteome at 96 hours post-infection revealed changes in the abundance of proteins associated with immune function, metabolism, cellular structure, insect development, transcription/translation and detoxification.Conclusion. Characterizing the impact of the fungal secretome on the host may provide an insight into how A. fumigatus damages tissue and suppresses the immune response during long-term pulmonary colonization.
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Affiliation(s)
- Aaron Curtis
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Pavel Dobes
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jacek Marciniak
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jana Hurychova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Hyrsl
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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Wang WH, Li CR, Qin XJ, Yang XQ, Xie SD, Jiang Q, Zou LH, Zhang YJ, Zhu GL, Zhao P. Novel Alkaloids from Aspergillus fumigatus VDL36, an Endophytic Fungus Associated with Vaccinium dunalianum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:10970-10980. [PMID: 38708787 DOI: 10.1021/acs.jafc.4c00371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Eleven alkaloids (1-11) including seven new ones, 1-7, were isolated from the solid fermentation of Aspergillus fumigatus VDL36, an endophytic fungus isolated from the leaves of Vaccinium dunalianum Wight (Ericaceae), a perennial evergreen shrub distributed across the Southwest regions of China, Myanmar, and Vietnam. Their structures were elucidated on the basis of extensive spectroscopic methods. The isolates were evaluated for in vitro antifungal activities against five phytopathogenic fungi (Fusarium oxysporum, Coriolus versicolor, Fusarium solani, Botrytis cinerea, Fusarium graminearum). As a result, the new compounds fumigaclavine I (1), 13-ethoxycyclotryprostatin A (5), 13-dehydroxycyclotryprostatin A (6), and 12β-hydroxy-13-oxofumitremorgin C (7) exhibited antifungal activities with MIC values of 7.8-62.5 μg/mL which were comparable to the two positive controls ketoconazole (MIC = 7.8-31.25 μg/mL) and carbendazim (MIC = 1.95-7.8 μg/mL). Furthermore, compounds 1 and 5 demonstrated potent protective and curative effects against the tomato gray mold in vivo. Preliminary structure-activity relationships of the tested indole diketopiperazine alkaloids indicate that the introduction of a substituent group at position C-13 enhances their biological activities.
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Affiliation(s)
- Wei-Hua Wang
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
- Yunnan Key Laboratory of Gastrodia and Fungi Symbiotic Biology, Zhaotong University, Zhaotong 657000, Yunnan, P. R. China
| | - Chu-Ran Li
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
| | - Xu-Jie Qin
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, P. R. China
| | - Xiao-Qin Yang
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
| | - Si-Da Xie
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
| | - Qian Jiang
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
| | - Li-Hua Zou
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
| | - Ying-Jun Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, P. R. China
| | - Guo-Lei Zhu
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
| | - Ping Zhao
- Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, P. R. China
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Groß M, Dika B, Loos E, Aliyeva-Schnorr L, Deising HB. The galactose metabolism genes UGE1 and UGM1 are novel virulence factors of the maize anthracnose fungus Colletotrichum graminicola. Mol Microbiol 2024; 121:912-926. [PMID: 38400525 DOI: 10.1111/mmi.15242] [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: 11/21/2023] [Revised: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024]
Abstract
Fungal cell walls represent the frontline contact with the host and play a prime role in pathogenesis. While the roles of the cell wall polymers like chitin and branched β-glucan are well understood in vegetative and pathogenic development, that of the most prominent galactose-containing polymers galactosaminogalactan and fungal-type galactomannan is unknown in plant pathogenic fungi. Mining the genome of the maize pathogen Colletotrichum graminicola identified the single-copy key galactose metabolism genes UGE1 and UGM1, encoding a UDP-glucose-4-epimerase and UDP-galactopyranose mutase, respectively. UGE1 is thought to be required for biosynthesis of both polymers, whereas UGM1 is specifically required for fungal-type galactomannan formation. Promoter:eGFP fusion strains revealed that both genes are expressed in vegetative and in pathogenic hyphae at all stages of pathogenesis. Targeted deletion of UGE1 and UGM1, and fluorescence-labeling of galactosaminogalactan and fungal-type galactomannan confirmed that Δuge1 mutants were unable to synthesize either of these polymers, and Δugm1 mutants did not exhibit fungal-type galactomannan. Appressoria of Δuge1, but not of Δugm1 mutants, were defective in adhesion, highlighting a function of galactosaminogalactan in the establishment of these infection cells on hydrophobic surfaces. Both Δuge1 and Δugm1 mutants showed cell wall defects in older vegetative hyphae and severely reduced appressorial penetration competence. On intact leaves of Zea mays, both mutants showed strongly reduced disease symptom severity, indicating that UGE1 and UGM1 represent novel virulence factors of C. graminicola.
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Affiliation(s)
- Maximilian Groß
- Faculty of Natural Sciences III, Institute for Agricultural and Nutritional Sciences, Phytopathology and Plant Protection, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Beate Dika
- Faculty of Natural Sciences III, Institute for Agricultural and Nutritional Sciences, Phytopathology and Plant Protection, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Elisabeth Loos
- Faculty of Natural Sciences III, Institute for Agricultural and Nutritional Sciences, Phytopathology and Plant Protection, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Lala Aliyeva-Schnorr
- Faculty of Natural Sciences III, Institute for Agricultural and Nutritional Sciences, Phytopathology and Plant Protection, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Holger B Deising
- Faculty of Natural Sciences III, Institute for Agricultural and Nutritional Sciences, Phytopathology and Plant Protection, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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Ouyang X, Reihill JA, Douglas LEJ, Martin SL. Airborne indoor allergen serine proteases and their contribution to sensitisation and activation of innate immunity in allergic airway disease. Eur Respir Rev 2024; 33:230126. [PMID: 38657996 PMCID: PMC11040391 DOI: 10.1183/16000617.0126-2023] [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: 06/22/2023] [Accepted: 02/28/2024] [Indexed: 04/26/2024] Open
Abstract
Common airborne allergens (pollen, animal dander and those from fungi and insects) are the main triggers of type I allergic disorder in the respiratory system and are associated with allergic rhinitis, allergic asthma, as well as immunoglobulin E (IgE)-mediated allergic bronchopulmonary aspergillosis. These allergens promote IgE crosslinking, vasodilation, infiltration of inflammatory cells, mucosal barrier dysfunction, extracellular matrix deposition and smooth muscle spasm, which collectively cause remodelling of the airways. Fungus and insect (house dust mite and cockroaches) indoor allergens are particularly rich in proteases. Indeed, more than 40 different types of aeroallergen proteases, which have both IgE-neutralising and tissue-destructive activities, have been documented in the Allergen Nomenclature database. Of all the inhaled protease allergens, 85% are classed as serine protease activities and include trypsin-like, chymotrypsin-like and collagenolytic serine proteases. In this article, we review and compare the allergenicity and proteolytic effect of allergen serine proteases as listed in the Allergen Nomenclature and MEROPS databases and highlight their contribution to allergic sensitisation, disruption of the epithelial barrier and activation of innate immunity in allergic airways disease. The utility of small-molecule inhibitors of allergen serine proteases as a potential treatment strategy for allergic airways disease will also be discussed.
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Affiliation(s)
- Xuan Ouyang
- School of Pharmacy, Queen's University Belfast, Belfast, UK
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Pontes L, Reichert-Lima F, Perini Leme Giordano AL, Moretti ML, Zaninelli Schreiber A. Challenging fungal infections in cystic fibrosis: a case of mixed Aspergillus species infection and antifungal combination testing. Access Microbiol 2024; 6:000758.v3. [PMID: 38737802 PMCID: PMC11083386 DOI: 10.1099/acmi.0.000758.v3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 02/29/2024] [Indexed: 05/14/2024] Open
Abstract
Aspergillus stands as the predominant fungal genus in the airways of cystic fibrosis (CF) patients, significantly contributing to their morbidity and mortality. Aspergillus fumigatus represents the primary causative species for infections, though the emergence of rare species within the Aspergillus section Fumigati has become noteworthy. Among these, Aspergillus lentulus is particularly significant due to its frequent misidentification and intrinsic resistance to azole antifungal agents. In the management of invasive aspergillosis and resistant infections, combination antifungal therapy has proven to be an effective approach. This report documents a case involving the death of a CF patient due to a pulmonary exacerbation linked to the colonization of multiple Aspergillus species, including A. lentulus, A. fumigatus, and A. terreus, and treated with Itraconazole (ITC) monotherapy. We delineated the procedures used to characterize the Aspergillus isolates in clinical settings and simulated in vitro the impact of the combination antifungal therapy on the isolates obtained from the patient. We evaluated three different combinations: Amphotericin B (AMB)+Voriconazole (VRC), AMB+Anidulafungin (AND), and VRC+AND. Notably, all strains isolated from the patient exhibited a significant decrease in their minimum inhibitory concentration (MIC) or minimum effective concentration (MEC) values when treated with all antifungal combinations. The VRC+AMB combination demonstrated the most synergistic effects. This case report emphasizes the critical importance of susceptibility testing and precise identification of Aspergillus species to enhance patient prognosis. It also underscores the potential benefits of combined antifungal treatment, which, in this case, could have led to a more favourable patient outcome.
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Affiliation(s)
- Laís Pontes
- School of Medical Sciences - University of Campinas, Campinas, São Paulo, Brazil
| | - Franqueline Reichert-Lima
- School of Medical Sciences in São José dos Campos – Humanitas, São José dos Campos – São Paulo, Brazil
| | | | - Maria Luiza Moretti
- School of Medical Sciences - University of Campinas, Campinas, São Paulo, Brazil
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Seo HW, Wassano NS, Amir Rawa MS, Nickles GR, Damasio A, Keller NP. A Timeline of Biosynthetic Gene Cluster Discovery in Aspergillus fumigatus: From Characterization to Future Perspectives. J Fungi (Basel) 2024; 10:266. [PMID: 38667937 PMCID: PMC11051388 DOI: 10.3390/jof10040266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
In 1999, the first biosynthetic gene cluster (BGC), synthesizing the virulence factor DHN melanin, was characterized in Aspergillus fumigatus. Since then, 19 additional BGCs have been linked to specific secondary metabolites (SMs) in this species. Here, we provide a comprehensive timeline of A. fumigatus BGC discovery and find that initial advances centered around the commonly expressed SMs where chemical structure informed rationale identification of the producing BGC (e.g., gliotoxin, fumigaclavine, fumitremorgin, pseurotin A, helvolic acid, fumiquinazoline). Further advances followed the transcriptional profiling of a ΔlaeA mutant, which aided in the identification of endocrocin, fumagillin, hexadehydroastechrome, trypacidin, and fumisoquin BGCs. These SMs and their precursors are the commonly produced metabolites in most A. fumigatus studies. Characterization of other BGC/SM pairs required additional efforts, such as induction treatments, including co-culture with bacteria (fumicycline/neosartoricin, fumigermin) or growth under copper starvation (fumivaline, fumicicolin). Finally, four BGC/SM pairs were discovered via overexpression technologies, including the use of heterologous hosts (fumicycline/neosartoricin, fumihopaside, sphingofungin, and sartorypyrone). Initial analysis of the two most studied A. fumigatus isolates, Af293 and A1160, suggested that both harbored ca. 34-36 BGCs. However, an examination of 264 available genomes of A. fumigatus shows up to 20 additional BGCs, with some strains showing considerable variations in BGC number and composition. These new BGCs present a new frontier in the future of secondary metabolism characterization in this important species.
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Affiliation(s)
- Hye-Won Seo
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - Natalia S. Wassano
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo 13083-970, Brazil;
| | - Mira Syahfriena Amir Rawa
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - Grant R. Nickles
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - André Damasio
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo 13083-970, Brazil;
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
- Department of Plant Pathology, University of Wisconsin, Madison, WI 53706, USA
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Rinker DC, Sauters TJC, Steffen K, Gumilang A, Raja HA, Rangel-Grimaldo M, Pinzan CF, de Castro PA, dos Reis TF, Delbaje E, Houbraken J, Goldman GH, Oberlies NH, Rokas A. Strain heterogeneity in a non-pathogenic fungus highlights factors contributing to virulence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.08.583994. [PMID: 38496489 PMCID: PMC10942418 DOI: 10.1101/2024.03.08.583994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Fungal pathogens exhibit extensive strain heterogeneity, including variation in virulence. Whether closely related non-pathogenic species also exhibit strain heterogeneity remains unknown. Here, we comprehensively characterized the pathogenic potentials (i.e., the ability to cause morbidity and mortality) of 16 diverse strains of Aspergillus fischeri, a non-pathogenic close relative of the major pathogen Aspergillus fumigatus. In vitro immune response assays and in vivo virulence assays using a mouse model of pulmonary aspergillosis showed that A. fischeri strains varied widely in their pathogenic potential. Furthermore, pangenome analyses suggest that A. fischeri genomic and phenotypic diversity is even greater. Genomic, transcriptomic, and metabolomic profiling identified several pathways and secondary metabolites associated with variation in virulence. Notably, strain virulence was associated with the simultaneous presence of the secondary metabolites hexadehydroastechrome and gliotoxin. We submit that examining the pathogenic potentials of non-pathogenic close relatives is key for understanding the origins of fungal pathogenicity.
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Affiliation(s)
- David C. Rinker
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Thomas J. C. Sauters
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Karin Steffen
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Adiyantara Gumilang
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Manuel Rangel-Grimaldo
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Camila Figueiredo Pinzan
- Faculdade de Ciencias Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Patrícia Alves de Castro
- Faculdade de Ciencias Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Thaila Fernanda dos Reis
- Faculdade de Ciencias Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Endrews Delbaje
- Faculdade de Ciencias Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Jos Houbraken
- Food and Indoor Mycology, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Gustavo H. Goldman
- Faculdade de Ciencias Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Antonis Rokas
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
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12
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Ghazanfari M, Abastabar M, Haghani I, Kermani F, Keikha N, Kholoujini M, Minooeianhaghighi MH, Jeddi SA, Shokri A, Ghojoghi A, Amirizad K, Azish M, Nasirzadeh Y, Roohi B, Nosratabadi M, Hedayati S, Ghanbari S, Valadan R, Hedayati MT. Electronic equipment and appliances in special wards of hospitals as a source of azole-resistant Aspergillus fumigatus: a multi-centre study from Iran. J Hosp Infect 2024; 145:65-76. [PMID: 38199436 DOI: 10.1016/j.jhin.2023.12.011] [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: 09/01/2023] [Revised: 12/05/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024]
Abstract
BACKGROUND Azole-resistant Aspergillus fumigatus (ARAf), reported as a global public health concern, has been unexpectedly observed in different countries. AIM To identify ARAf and detect azole resistance related to the CYP51A mutation in different hospital environmental samples. METHODS In this multi-centre study from Iran, surfaces of electronic equipment and appliances from different hospitals in Iran were sampled using cotton swabs. All samples were cultured using azole-containing agar plates (ACAPs). Recovered Aspergillus isolates were identified at the species level using partial DNA sequencing of the β-tubulin gene. The azole susceptibility testing of A. fumigatus isolates was performed using the Clinical and Laboratory Standards Institute M38-A3 guideline. The sequencing of the CYP51A gene was also performed to detect mutations related to resistance. FINDINGS Out of the 693 collected samples, 89 (12.8%) Aspergillus species were recovered from ACAPs. Aspergillus fumigatus (41.6%) was the most prevalent, followed by A. tubingensis (23.6%) and A. niger (15.6%). Among 37 isolates of A. fumigatus, 19 (51.3%) showed high minimum inhibitory concentration (MIC) values to at least one of the three azoles, voriconazole, itraconazole, and posaconazole. CYP51A polymorphisms were detected in all 19 isolates, of which 52.6% showed the TR34/L98H mutation. Other detected mutations were G432C, G448S, G54E/G138C, F46Y, and Y121F/M220I/D255E. T289F and G432C were the first reported mutations in ARAf. CONCLUSION There was a considerable level of azole resistance in hospital environmental samples, a serious warning for patients vulnerable to aspergillosis. Our findings have also revealed a different mutation pattern in the CYP51A gene.
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Affiliation(s)
- M Ghazanfari
- Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran; Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - M Abastabar
- Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran; Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - I Haghani
- Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - F Kermani
- Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - N Keikha
- Infectious Disease and Tropical Medicine Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran
| | - M Kholoujini
- Beheshti Hospital, Hamadan University of Medical Sciences, Hamadan, Iran
| | - M H Minooeianhaghighi
- Department of Medical Microbiology, Faculty of Medicine, Infectious Diseases Research Center, Gonabad University of Medical Sciences, Gonabad, Iran
| | - S A Jeddi
- Department of Laboratory Sciences, School of Allied Sciences, Abadan University of Medical Sciences, Abadan, Iran
| | - A Shokri
- Vector-Borne Diseases Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - A Ghojoghi
- Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - K Amirizad
- Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - M Azish
- Department of Medical Parasitology and Mycology, School of Medicine, Dezful University of Medical Sciences, Dezful, Iran
| | - Y Nasirzadeh
- Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - B Roohi
- Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - M Nosratabadi
- Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Department of Medical Laboratory Sciences, Sirjan Faculty of Medical Sciences, Sirjan, Iran
| | - S Hedayati
- Student Research Committee Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - S Ghanbari
- Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - R Valadan
- Department of Immunology/Molecular and Cell Biology Research Center (MCBRC), Mazandaran University of Medical Sciences, Sari, Iran
| | - M T Hedayati
- Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran; Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
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13
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Jentsch MC, Lübke S, Schrödl W, Volke D, Krizsan A, Hoffmann R, Kaiser-Thom S, Gerber V, Marti E, Wagner B, Schnabel CL. Immunoproteomics enable broad identification of new Aspergillus fumigatus antigens in severe equine asthma. Front Immunol 2024; 15:1347164. [PMID: 38487534 PMCID: PMC10937411 DOI: 10.3389/fimmu.2024.1347164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/01/2024] [Indexed: 03/17/2024] Open
Abstract
Introduction Severe equine asthma (SEA) is a common chronic disease of adult horses with characteristic recurrent airway obstruction and similarities to neutrophilic asthma in humans. As an extrinsic stimulus, hay dust exposure is a major risk factor and induces acute exacerbation in susceptible horses. However, single inducing agents of SEA have hardly been identified on a molecular basis. Aspergillus fumigatus (A. fumigatus) is a common mold species in hay and has been described as a major provoking agent of SEA. Methods Aiming to identify disease-relevant antigens, we analyzed A. fumigatus using an immunoproteomics approach on two-dimensional immunoblots of A. fumigatus protein probed with serum from environmentally matched asthmatic and healthy horses (n=5 pairs). A. fumigatus binding serum immunoglobulins (Pan-Ig), and the isotypes IgG4/7 and IgG3/5 were quantified for each protein spot and then compared between asthmatic and healthy horses. Results and discussion For 21 out of 289 spots serum immunoglobulin (Ig) binding was different between the two groups for Pan-Ig or the isotypes. If differences were detected, Pan-Ig and IgG4/7 binding to the proteins were lower, while IgG3/5 binding was higher in asthmatic than healthy horse sera. Proteins were extracted from the 21 spots of interest and analyzed by liquid chromatography mass spectrometry. Eight prioritized proteins (candidate antigens) were expressed as recombinant proteins. Some of these have been previously described as major or minor A. fumigatus allergens, alongside other proteins, most with hydrolase activity. Recombinant candidate antigens were tested on 1D immunoblots to confirm their relevance as antigens by serum antibody binding. Four proteins (beta-hexosaminidase, class II aldolase/adducin domain protein, glucoamylase, peptide hydrolase B0XX53) showed different antibody binding characteristics between asthmatic and healthy horses and are likely relevant antigens in SEA. Their identification can provide the basis for innovative diagnostics, prevention, or therapeutic approaches. Additionally, a more profound understanding of SEA and its potential underlying mechanisms can be established. Elevated serum IgG3/5 antibodies correlate with T helper cell 2 responses in other equine pathologies, and the recombinant SEA antigens developed here can become instrumental in analyzing the involvement of SEA-specific T cell responses and Ig responses in future studies.
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Affiliation(s)
- Maria-Christin Jentsch
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Sabrina Lübke
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Wieland Schrödl
- Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Daniela Volke
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | - Andor Krizsan
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | - Ralf Hoffmann
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | - Sarah Kaiser-Thom
- Swiss Institute of Equine Medicine, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Vinzenz Gerber
- Swiss Institute of Equine Medicine, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Eliane Marti
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Bettina Wagner
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Christiane L. Schnabel
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
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14
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Chen Y, Gao F, Chen X, Tao S, Chen P, Lin W. The basic leucine zipper transcription factor MeaB is critical for biofilm formation, cell wall integrity, and virulence in Aspergillus fumigatus. mSphere 2024; 9:e0061923. [PMID: 38284755 PMCID: PMC10900910 DOI: 10.1128/msphere.00619-23] [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: 10/17/2023] [Accepted: 12/18/2023] [Indexed: 01/30/2024] Open
Abstract
The regulation of fungal cell wall biosynthesis is crucial for cell wall integrity maintenance and directly impacts fungal pathogen virulence. Although numerous genes are involved in fungal cell wall polysaccharide biosynthesis through multiple pathways, the underlying regulatory mechanism is still not fully understood. In this study, we identified and functionally characterized a direct downstream target of SomA, the basic-region leucine zipper transcription factor MeaB, playing a certain role in Aspergillus fumigatus cell wall integrity. Loss of meaB reduces hyphal growth, causes severe defects in galactosaminogalactan-mediated biofilm formation, and attenuates virulence in a Galleria mellonella infection model. Furthermore, the meaB null mutant strain exhibited hypersensitivity to cell wall-perturbing agents and significantly alters the cell wall structure. Transcriptional profile analysis revealed that MeaB positively regulates the expression of the galactosaminogalactan biosynthesis and β-1,3-glucanosyltransferase genes uge3, agd3, and sph3 and gel1, gel5, and gel7, respectively, as well as genes involved in amino sugar and nucleotide sugar metabolism. Further study demonstrated that MeaB could respond to cell wall stress and contribute to the proper expression of mitogen-activated protein kinase genes mpkA and mpkC in the presence of different concentrations of congo red. In conclusion, A. fumigatus MeaB plays a critical role in cell wall integrity by governing the expression of genes encoding cell wall-related proteins, thus impacting the virulence of this fungus.IMPORTANCEAspergillus fumigatus is a common opportunistic mold that causes life-threatening infections in immunosuppressed patients. The fungal cell wall is a complex and dynamic organelle essential for the development of pathogenic fungi. Genes involved in cell wall polysaccharide biosynthesis and remodeling are crucial for fungal pathogen virulence. However, the potential regulatory mechanism for cell wall integrity remains to be fully defined in A. fumigatus. In the present study, we identify basic-region leucine zipper transcription factor MeaB as an important regulator of cell wall galactosaminogalactan biosynthesis and β-1,3-glucan remodeling that consequently impacts stress response and virulence of fungal pathogens. Thus, we illuminate a mechanism of transcriptional control fungal cell wall polysaccharide biosynthesis and stress response. As these cell wall components are promising therapeutic targets for fungal infections, understanding the regulatory mechanism of such polysaccharides will provide new therapeutic opportunities.
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Affiliation(s)
- Yuan Chen
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Fei Gao
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Xiaojin Chen
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Siyuan Tao
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Peiying Chen
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Wei Lin
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
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15
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Schwarz C, Eschenhagen PN, Mainz JG, Schmidergall T, Schuette H, Romanowska E. Pulmonary Aspergillosis in People with Cystic Fibrosis. Semin Respir Crit Care Med 2024; 45:128-140. [PMID: 38286138 DOI: 10.1055/s-0043-1777267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
In the last decade, fungal respiratory diseases have been increasingly investigated for their impact on the clinical course of people with cystic fibrosis (CF), with a particular focus on infections caused by Aspergillus spp. The most common organisms from this genus detected from respiratory cultures are Aspergillus fumigatus and Aspergillus terreus, followed by Aspergillus flavus, Aspergillus niger, and Aspergillus nidulans. These species have been identified to be both chronic colonizers and sources of active infection and may negatively impact lung function in people with CF. This review article discusses definitions of aspergillosis, challenges in clinical practice, and current literature available for laboratory findings, clinical diagnosis, and treatment options for pulmonary diseases caused by Aspergillus spp. in people with CF.
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Affiliation(s)
- C Schwarz
- HMU-Health and Medical University, Potsdam, Germany
- Division Cystic Fibrosis, Clinic Westbrandenburg, Potsdam, Germany
| | - P N Eschenhagen
- HMU-Health and Medical University, Potsdam, Germany
- Division Cystic Fibrosis, Clinic Westbrandenburg, Potsdam, Germany
| | - J G Mainz
- Department of Paediatric Pneumology, Allergology, Cystic Fibrosis Center, Klinikum Westbrandenburg, Brandenburg a. d. Havel, Germany
- University Hospital of the Brandenburg Medical School, Brandenburg a. d. Havel, Germany
| | - T Schmidergall
- HMU-Health and Medical University, Potsdam, Germany
- Division Cystic Fibrosis, Clinic Westbrandenburg, Potsdam, Germany
| | - H Schuette
- Pneumology and Respiratory Medicine, Ernst von Bergmann Klinikum, Potsdam, Germany
| | - E Romanowska
- HMU-Health and Medical University, Potsdam, Germany
- Division Cystic Fibrosis, Clinic Westbrandenburg, Potsdam, Germany
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16
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Janssens I, Lambrecht BN, Van Braeckel E. Aspergillus and the Lung. Semin Respir Crit Care Med 2024; 45:3-20. [PMID: 38286136 PMCID: PMC10857890 DOI: 10.1055/s-0043-1777259] [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] [Indexed: 01/31/2024]
Abstract
The filamentous fungus Aspergillus causes a wide spectrum of diseases in the human lung, with Aspergillus fumigatus being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of Aspergillus in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.
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Affiliation(s)
- Iris Janssens
- Department of Internal Medicine and Paediatrics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
| | - Bart N. Lambrecht
- Department of Internal Medicine and Paediatrics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Pulmonary Medicine, ErasmusMC; Rotterdam, The Netherlands
| | - Eva Van Braeckel
- Department of Internal Medicine and Paediatrics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
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17
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Shao Y, Shen M, Peng D, Cheng W, Mao C, Zhang H, Sun Y. Observation of a Bone Invasion Model of Aspergillus fumigatus In Vitro and Analysis of the Antifungal Susceptibility. Mycopathologia 2024; 189:4. [PMID: 38231458 DOI: 10.1007/s11046-023-00817-y] [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: 09/16/2023] [Accepted: 12/13/2023] [Indexed: 01/18/2024]
Abstract
BACKGROUND Recently, the prevalence of invasive fungal infections has been on the rise, and one of the prevalent symptoms frequently observed is bone deterioration and bone loss. MATERIALS AND METHODS Using an in vitro model we studied how Aspergillus fumigatus invades the bone. Pathological analysis was then employed to observe the structure and distinctive features of the invading fungal elements within the bone invasion model. Meanwhile, the antifungal effects of itraconazole, voriconazole, posaconazole, and amphotericin B were evaluated. RESULTS The pathological findings showed that in the experimental group, fungal spores and hyphae invaded the bone tissue or were observed growing in the vicinity of the bone edge tissues, as indicated by both HE and PAS staining. In contrast, no fungal elements were observed in the control group, indicating that the in vitro bone invasion model of A. fumigatus was successfully constructed. Furthermore, the findings from the antifungal sensitivity test demonstrated that the lowest effective concentrations of antifungal drugs against the bone invasion model were as follows: 4 μg/ml for itraconazole, 0.5 μg/ml for voriconazole, 2 μg/ml for posaconazole, and 2 μg/ml for amphotericin B. DISCUSSION The successful construction of the bone invasion model of A. fumigatus has provided a solid basis for future investigations into the mechanisms underlying A. fumigatus bone invasion and the study of its virulence factors. Utilizing bone models is of utmost importance in advancing the development of novel antifungal treatment approaches, as well as in effectively preventing and treating fungal bone invasion and osteolytic diseases.
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Affiliation(s)
- Yan Shao
- Department of Orthopedics, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, Hubei, China
| | - Min Shen
- Department of Otolaryngology Head and Neck Surgery, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, Hubei, China
| | - Dan Peng
- Department of Otolaryngology Head and Neck Surgery, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, Hubei, China
| | - Wenxu Cheng
- Department of Otolaryngology Head and Neck Surgery, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, Hubei, China
| | - Chenggang Mao
- Department of Otolaryngology Head and Neck Surgery, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, Hubei, China
| | - Heng Zhang
- Department of Dermatology, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, 434020, Hubei, China
| | - Yi Sun
- Department of Dermatology, Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, 434020, Hubei, China.
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18
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Pan J, Yang X, Hu C, Fu T, Zhang X, Liu Z, Wang Y, Zhang F, He X, Yu JH. Functional, transcriptomic, and lipidomic studies of the choC gene encoding a phospholipid methyltransferase in Aspergillus fumigatus. Microbiol Spectr 2024; 12:e0216823. [PMID: 38009944 PMCID: PMC10783049 DOI: 10.1128/spectrum.02168-23] [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: 06/06/2023] [Accepted: 10/02/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE This study explored the phospholipid metabolic pathway in A. fumigatus and its relationship with fungal growth, metabolism, and pathogenicity. ChoC, based on its critical roles in many aspects of the fungus and relatively conserved characteristics in filamentous fungi with low similarity with mammalian ones, can be a novel target of new antifungal drugs.
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Affiliation(s)
- Jiao Pan
- Institute for Cultural Heritage and History of Science and Technology, University of Science and Technology Beijing, Beijing, China
| | - Xinyu Yang
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Cuiting Hu
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Tongtong Fu
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiuyan Zhang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zijun Liu
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yu Wang
- Institute for Cultural Heritage and History of Science and Technology, University of Science and Technology Beijing, Beijing, China
| | - Fengyu Zhang
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoyuan He
- Department of Hematology, Tianjin First Central Hospital, Tianjin, China
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin, Madison, Wisconsin, USA
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Paiva DS, Fernandes L, Portugal A, Trovão J. First Genome Sequence of the Microcolonial Black Fungus Saxispiralis lemnorum MUM 23.14: Insights into the Unique Genomic Traits of the Aeminiaceae Family. Microorganisms 2024; 12:104. [PMID: 38257931 PMCID: PMC10820743 DOI: 10.3390/microorganisms12010104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/15/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024] Open
Abstract
Saxispiralis lemnorum MUM 23.14 is an extremotolerant microcolonial black fungus, originally isolated from a biodeteriorated limestone artwork in Portugal. This recently introduced species belongs to the Aeminiaceae family, representing the second member of this monophyletic clade. This fungus exhibits a unique set of characteristics, including xerophily, cold tolerance, high UV radiation tolerance, and an exceptional ability to thrive in NaCl concentrations of up to 30% while also enduring pH levels ranging from 5 to 11. To gain insights into its genomic traits associated with stress resistance mechanisms, specialization, and their potential implications in stone biodeterioration, we conducted a comprehensive genome sequencing and analysis. This draft genome not only marks the first for the Saxispiralis genus but also the second for the Aeminiaceae family. Furthermore, we performed two comparative genomic analyses: one focusing on the closest relative within the Aeminiaceae family, Aeminium ludgeri, and another encompassing the genome of different extremotolerant black fungi. In this study, we successfully achieved high genome completeness for S. lemnorum and confirmed its close phylogenetic relationship to A. ludgeri. Our findings revealed traits contributing to its extremophilic nature and provided insights into potential mechanisms contributing to stone biodeterioration. Many traits are common to both Aeminiaceae species and are shared with other black fungi, while numerous unique traits may be attributed to species-specific characteristics.
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Affiliation(s)
- Diana S. Paiva
- Centre for Functional Ecology (CFE)—Science for People & the Planet, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal (J.T.)
| | - Luís Fernandes
- Centre for Functional Ecology (CFE)—Science for People & the Planet, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal (J.T.)
| | - António Portugal
- Centre for Functional Ecology (CFE)—Science for People & the Planet, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal (J.T.)
- FitoLab—Laboratory for Phytopathology, Instituto Pedro Nunes (IPN), Rua Pedro Nunes, 3030-199 Coimbra, Portugal
- TERRA—Associate Laboratory for Sustainable Land Use and Ecosystem Services, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - João Trovão
- Centre for Functional Ecology (CFE)—Science for People & the Planet, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal (J.T.)
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20
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Son YE, Han J, Lee KT, Park HS. Pleiotropic functions of SscA on the asexual spore of the human pathogenic fungus Aspergillus fumigatus. Mycology 2023; 15:238-254. [PMID: 38813476 PMCID: PMC11132850 DOI: 10.1080/21501203.2023.2294061] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/06/2023] [Indexed: 05/31/2024] Open
Abstract
Asexual spores, called conidia, are key reproductive fungal particles that enable survival in harsh environmental conditions or host systems. The conidia can infect humans, animals, and plants to cause various fungal diseases. Transcription factors, including VosA, WetA, and SscA, have key roles in conidia formation and long-term survival in Aspergillus nidulans. Herein, we report the pleiotropic functions of SscA in the conidia of the human pathogen A. fumigatus. The deletion of sscA increased conidia formation despite decreased fungal growth. Absence of sscA impaired long-term survival and reduced spore resistance to various stresses, including heat, UV, and oxidation. Transcriptomic analyses showed that SscA involved the mRNA expression of cell wall organisation-related genes. Importantly, the sscA deletion mutant conidia contained an increased amount of β-glucan and chitin compared to wild type conidia. In addition, conidial gliotoxin production was decreased in the sscA deletion strain. Overall, SscA has pleiotropic roles in conidia formation, maturation and dormancy and mycotoxin production in A. fumigatus.
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Affiliation(s)
- Ye-Eun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | - Jiwoo Han
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, Republic of Korea
| | - Kyung-Tae Lee
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, Republic of Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
- Department of Integrative Biology, Kyungpook National University, Daegu, Republic of Korea
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21
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Earle K, Valero C, Conn DP, Vere G, Cook PC, Bromley MJ, Bowyer P, Gago S. Pathogenicity and virulence of Aspergillus fumigatus. Virulence 2023; 14:2172264. [PMID: 36752587 PMCID: PMC10732619 DOI: 10.1080/21505594.2023.2172264] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 12/16/2022] [Indexed: 02/09/2023] Open
Abstract
Pulmonary infections caused by the mould pathogen Aspergillus fumigatus are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.
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Affiliation(s)
- Kayleigh Earle
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Clara Valero
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Daniel P. Conn
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - George Vere
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Peter C. Cook
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Paul Bowyer
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Sara Gago
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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22
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Dai M, Du W, Lu L, Zhang S. Transcription factors SltA and CrzA reversely regulate calcium homeostasis under calcium-limited conditions. Appl Environ Microbiol 2023; 89:e0117023. [PMID: 37874299 PMCID: PMC10686095 DOI: 10.1128/aem.01170-23] [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: 07/11/2023] [Accepted: 09/11/2023] [Indexed: 10/25/2023] Open
Abstract
IMPORTANCE Calcium ions are ubiquitous intracellular signaling molecules for many signaling pathways regulating the fungal response to stress and antifungal drugs. The concentration of intracellular calcium is tightly regulated in its storage, release, and distribution. CrzA is the best-studied transcription factor that regulates this process under sufficient calcium or other external signals. However, CrzA was excluded from nuclei and then lost transcriptional activation under calcium-limited conditions. The regulators in the Ca2+ signaling pathway under calcium-limited conditions remain unclear. Here, we identified SltA as a key regulator in the Ca2+ signaling pathway under calcium-limited conditions, and the underlying mechanisms were further explored in Aspergillus fumigatus. These findings reveal a transcriptional control pathway that precisely regulates calcium homeostasis under calcium-limited conditions.
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Affiliation(s)
- Mengyao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Wenlong Du
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
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23
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Liu Z, Ma K, Zhang X, Song X, Qin Y. Different Putative Methyltransferases Have Different Effects on the Expression Patterns of Cellulolytic Genes. J Fungi (Basel) 2023; 9:1118. [PMID: 37998923 PMCID: PMC10671955 DOI: 10.3390/jof9111118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/07/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023] Open
Abstract
Putative methyltranferase LaeA and LaeA-like proteins, conserved in many filamentous fungi, regulate fungal growth, development, virulence, the biosynthesis of secondary metabolites, and the production of cellulolytic enzymes. Penicillium oxaliucm is a typical fungus that produces cellulolytic enzymes. In this study, we reported the biological function of eight putative methyltransferases (PoMtr23C/D/E/F/G/H and PoMtr25A/B) containing a methyltransf_23 or methyltransf_25 domain, with a focus on their roles in the production of cellulolytic enzymes. In P. oxalicum, various methyltransferase genes displayed different transcriptional levels. The genes Pomtr23C and Pomtr25A exhibited high transcriptional levels, while Pomtr23D/E/F/G/H and Pomtr25B were transcribed constantly at low levels. The gene deletion mutants (Δmtr23C/D/E/F/G/H and Δmtr25A/B) were constructed. Various mutants have different patterns in cellulolytic enzyme production. Compared to the WT, the largest increase in filter paper activity (FPA, indicating total cellulase activity) was observed in the Δmtr23G mutant, the only mutant with a cellulolytic halo surrounding the colony. Three mutants (Δmtr23C/D and Δmtr25A) also showed increased cellulolytic enzyme production. The Δmtr23E and Δmtr25B mutants displayed decreased FPA activity, while the Δmtr23F and Δmtr23H mutants displayed similar patterns of cellulolytic enzyme production compared with the WT. The assay of transcriptional levels of cellobiohydrolase gene Pocbh1 and β-1,4-endoglucanase Poeg1 supported that higher cellulolytic gene transcription resulted in higher production of cellulolytic enzymes, and vice versa. The transcriptional levels of two transcription factors, activator XlnR and repressor CreA, were measured. The high transcription level of the PoxlnR gene in the Δmtr23D mutant should be one reason for the increased transcription of its cellulolytic enzyme gene. Both XlnR and CreA transcriptional levels increased in the Δmtr23G mutant, but the former showed a more significant increase than the latter, indicating that the activation effect predominated. The PoMtr25A is localized in the nucleus. The catalytic subunit SNF2 of the SWI/SNF chromatin-remodeling complex was found as one of the interacting proteins of PoMtr25A via tandem affinity purification coupled with mass spectrometry. PoMtr25A may affect not only the transcription of repressor CreA but also by recruiting SWI/SNF complexes that affect chromatin structure, thereby regulating the transcription of target genes.
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Affiliation(s)
- Zhongjiao Liu
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
| | - Kexuan Ma
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xiujun Zhang
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- School of Biological Science and Technology, University of Jinan, Jinan 250024, China
| | - Xin Song
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
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da Fonseca LMM, Braga VF, Tonani L, Grizante Barião PH, Nascimento E, Martinez R, von Zeska Kress MR. Surveillance of Amphotericin B and Azole Resistance in Aspergillus Isolated from Patients in a Tertiary Teaching Hospital. J Fungi (Basel) 2023; 9:1070. [PMID: 37998875 PMCID: PMC10672583 DOI: 10.3390/jof9111070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/08/2023] [Accepted: 10/09/2023] [Indexed: 11/25/2023] Open
Abstract
The genus Aspergillus harbors human infection-causing pathogens and is involved in the complex one-health challenge of antifungal resistance. Here, a 6-year retrospective study was conducted with Aspergillus spp. isolated from patients with invasive, chronic, and clinically suspected aspergillosis in a tertiary teaching hospital. A total of 64 Aspergillus spp. clinical isolates were investigated regarding molecular identification, biofilm, virulence in Galleria mellonella, antifungal susceptibility, and resistance to amphotericin B and azoles. Aspergillus section Fumigati (A. fumigatus sensu stricto, 62.5%) and section Flavi (A. flavus, 20.3%; A. parasiticus, 14%; and A. tamarii, 3.1%) have been identified. Aspergillus section Flavi clinical isolates were more virulent than section Fumigati clinical isolates. Furthermore, scant evidence supports a link between biofilm formation and virulence. The susceptibility of the Aspergillus spp. clinical isolates to itraconazole, posaconazole, voriconazole, and amphotericin B was evaluated. Most Aspergillus spp. clinical isolates (67.2%) had an AMB MIC value equal to or above 2 µg/mL, warning of a higher probability of therapeutic failure in the region under study. In general, the triazoles presented MIC values above the epidemiological cutoff value. The high triazole MIC values of A. fumigatus s.s. clinical isolates were investigated by sequencing the promoter region and cyp51A locus. The Cyp51A amino acid substitutions F46Y, M172V, N248T, N248K, D255E, and E427K were globally detected in 47.5% of A. fumigatus s.s. clinical isolates, and most of them are associated with high triazole MICs. Even so, the findings support voriconazole or itraconazole as the first therapeutic choice for treating Aspergillus infections. This study emphasizes the significance of continued surveillance of Aspergillus spp. infections to help overcome the gap in knowledge of the global fungal burden of infections and antifungal resistance, supporting public health initiatives.
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Affiliation(s)
- Lívia Maria Maciel da Fonseca
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Vanessa Fávaro Braga
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Ludmilla Tonani
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Patrícia Helena Grizante Barião
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
| | - Erika Nascimento
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto 14040-900, Brazil; (E.N.); (R.M.)
| | - Roberto Martinez
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto 14040-900, Brazil; (E.N.); (R.M.)
| | - Marcia Regina von Zeska Kress
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão, Universidade de Sao Paulo, Ribeirao Preto 14040-903, Brazil; (L.M.M.d.F.); (L.T.); (P.H.G.B.)
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25
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Li Y, Dai M, Lu L, Zhang Y. The C 2H 2-Type Transcription Factor ZfpA, Coordinately with CrzA, Affects Azole Susceptibility by Regulating the Multidrug Transporter Gene atrF in Aspergillus fumigatus. Microbiol Spectr 2023; 11:e0032523. [PMID: 37318356 PMCID: PMC10434176 DOI: 10.1128/spectrum.00325-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/26/2023] [Indexed: 06/16/2023] Open
Abstract
The incidence of invasive aspergillosis caused by Aspergillus fumigatus has risen steadily over the past few decades due to the limited effective treatment options and the emergence of antifungal-resistant isolates. In clinic-isolated A. fumigatus, the azole resistance mechanism is primarily caused by mutations of the drug target and/or overexpression of drug efflux pumps. However, knowledge about how drug efflux pumps are transcriptionally regulated is limited. In this study, we found that loss of a C2H2 transcription factor ZfpA (zinc finger protein) results in the marked upregulation of a series of drug efflux pump-encoding genes, especially atrF, which contributes to azole drug resistance in A. fumigatus. CrzA is a previously identified positive transcription factor for genes of drug efflux pumps, and ZfpA transcriptionally inhibits expressions of drug efflux pumps in a CrzA-dependent way. Under the treatment of azoles, both ZfpA and CrzA transfer to nuclei and coregulate the expression of multidrug transporters and then keep normal drug susceptibility in fungal cells. Findings in this study demonstrated that ZfpA is not only involved in fungal growth and virulence potential but also negatively regulates antifungal drug susceptibility. IMPORTANCE Conserved across all kingdoms of life, ABC transporters comprise one of the largest protein families. They are associated with multidrug resistance, affecting aspects such as resistance to antimicrobials or anticancer drugs. Despite the importance of ABC transporters in multidrug resistance, the understanding of their regulatory network is still limited in A. fumigatus. Here, we found that the loss of the transcription factor ZfpA induces the expression of the ABC transporter gene atrF, altering azole susceptibility in A. fumigatus. ZfpA, coordinately with CrzA, affects the azole susceptibility by regulating the expression of the ABC transporter gene atrF. These findings reveal the regulatory mechanism of the ABC transporter gene atrF in A. fumigatus.
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Affiliation(s)
- Yeqi Li
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Mengyao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Yuanwei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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26
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Freitas MS, Bitencourt TA, Rezende CP, Martins NS, Dourado TDMH, Tirapelli CR, Almeida F. Aspergillus fumigatus Extracellular Vesicles Display Increased Galleria mellonella Survival but Partial Pro-Inflammatory Response by Macrophages. J Fungi (Basel) 2023; 9:jof9050541. [PMID: 37233252 DOI: 10.3390/jof9050541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
Fungal extracellular vesicles (EVs) mediate intra- and interspecies communication and are critical in host-fungus interaction, modulating inflammation and immune responses. In this study, we evaluated the in vitro pro- and anti-inflammatory properties of Aspergillus fumigatus EVs over innate leukocytes. A. fumigatus EVs induced a partial proinflammatory response by macrophages, characterized by increased tumor necrosis factor-alpha production, and increased gene expression of induced nitric oxide synthase and adhesion molecules. EVs induce neither NETosis in human neutrophils nor cytokine secretion by peripheral mononuclear cells. However, prior inoculation of A. fumigatus EVs in Galleria mellonella larvae resulted in increased survival after the fungal challenge. Taken together, these findings show that A. fumigatus EVs play a role in protection against fungal infection, although they induce a partial pro-inflammatory response.
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Affiliation(s)
- Mateus Silveira Freitas
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | - Tamires Aparecida Bitencourt
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | - Caroline Patini Rezende
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | - Nubia Sabrina Martins
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | | | - Carlos R Tirapelli
- Laboratory of Pharmacology, Department of Psychiatric Nursing and Human Sciences, College of Nursing of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-902, SP, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
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27
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Schiefermeier-Mach N, Heinrich L, Lechner L, Perkhofer S. Regulation of Surfactant Protein Gene Expression by Aspergillus fumigatus in NCl-H441 Cells. Microorganisms 2023; 11:microorganisms11041011. [PMID: 37110432 PMCID: PMC10143823 DOI: 10.3390/microorganisms11041011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that causes serious lung diseases in immunocompromised patients. The lung surfactant produced by alveolar type II and Clara cells in the lungs is an important line of defense against A. fumigatus. The surfactant consists of phospholipids and surfactant proteins (SP-A, SP-B, SP-C and SP-D). The binding to SP-A and SP-D proteins leads to the agglutination and neutralization of lung pathogens as well as the modulation of immune responses. SP-B and SP-C proteins are essential for surfactant metabolism and can modulate the local immune response; however, the molecular mechanisms remain unclear. We investigated changes in the SP gene expression in human lung NCI-H441 cells infected with conidia or treated with culture filtrates obtained from A. fumigatus. To further identify fungal cell wall components that may affect the expression of SP genes, we examined the effect of different A. fumigatus mutant strains, including dihydroxynaphthalene (DHN)-melanin-deficient ΔpksP, galactomannan (GM)-deficient Δugm1 and galactosaminogalactan (GAG)-deficient Δgt4bc strains. Our results show that the tested strains alter the mRNA expression of SP, with the most prominent and consistent downregulation of the lung-specific SP-C. Our findings also suggest that secondary metabolites rather than the membrane composition of conidia/hyphae inhibit SP-C mRNA expression in NCI-H441 cells.
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Affiliation(s)
- Natalia Schiefermeier-Mach
- Research and Innovation Unit, Health University of Applied Sciences Tyrol/FH Gesundheit Tirol, 6020 Innsbruck, Austria
| | - Lea Heinrich
- Research and Innovation Unit, Health University of Applied Sciences Tyrol/FH Gesundheit Tirol, 6020 Innsbruck, Austria
| | - Lukas Lechner
- Research and Innovation Unit, Health University of Applied Sciences Tyrol/FH Gesundheit Tirol, 6020 Innsbruck, Austria
| | - Susanne Perkhofer
- Research and Innovation Unit, Health University of Applied Sciences Tyrol/FH Gesundheit Tirol, 6020 Innsbruck, Austria
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28
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Mead ME, de Castro PA, Steenwyk JL, Gangneux JP, Hoenigl M, Prattes J, Rautemaa-Richardson R, Guegan H, Moore CB, Lass-Flörl C, Reizine F, Valero C, Van Rhijn N, Bromley MJ, Rokas A, Goldman GH, Gago S. COVID-19-Associated Pulmonary Aspergillosis Isolates Are Genomically Diverse but Similar to Each Other in Their Responses to Infection-Relevant Stresses. Microbiol Spectr 2023; 11:e0512822. [PMID: 36946762 PMCID: PMC10100753 DOI: 10.1128/spectrum.05128-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/25/2023] [Indexed: 03/23/2023] Open
Abstract
Secondary infections caused by the pulmonary fungal pathogen Aspergillus fumigatus are a significant cause of mortality in patients with severe coronavirus disease 19 (COVID-19). Even though epithelial cell damage and aberrant cytokine responses have been linked to susceptibility to COVID-19-associated pulmonary aspergillosis (CAPA), little is known about the mechanisms underpinning copathogenicity. Here, we analyzed the genomes of 11 A. fumigatus isolates from patients with CAPA in three centers from different European countries. CAPA isolates did not cluster based on geographic origin in a genome-scale phylogeny of representative A. fumigatus isolates. Phenotypically, CAPA isolates were more similar to the A. fumigatus A1160 reference strain than to the Af293 strain when grown in infection-relevant stresses, except for interactions with human immune cells wherein macrophage responses were similar to those induced by the Af293 reference strain. Collectively, our data indicate that CAPA isolates are genomically diverse but are more similar to each other in their responses to infection-relevant stresses. A larger number of isolates from CAPA patients should be studied to better understand the molecular epidemiology of CAPA and to identify genetic drivers of copathogenicity and antifungal resistance in patients with COVID-19. IMPORTANCE Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) has been globally reported as a life-threatening complication in some patients with severe COVID-19. Most of these infections are caused by the environmental mold Aspergillus fumigatus, which ranks third in the fungal pathogen priority list of the WHO. However, little is known about the molecular epidemiology of Aspergillus fumigatus CAPA strains. Here, we analyzed the genomes of 11 A. fumigatus isolates from patients with CAPA in three centers from different European countries, and carried out phenotypic analyses with a view to understanding the pathophysiology of the disease. Our data indicate that A. fumigatus CAPA isolates are genomically diverse but are more similar to each other in their responses to infection-relevant stresses.
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Affiliation(s)
- Matthew E. Mead
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jacob L. Steenwyk
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Jean-Pierre Gangneux
- University of Rennes, CHU Rennes, Inserm, EHESP, IRSET (Institut de recherche en santé, environnement et travail), Rennes, France
| | - Martin Hoenigl
- Division of Infectious Diseases, Medical University of Graz, Graz, Austria
- Biotech Med, Graz, Austria
| | - Juergen Prattes
- Division of Infectious Diseases, Medical University of Graz, Graz, Austria
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester and Department of Infectious Diseases, Manchester University, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester, United Kingdom
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Hélène Guegan
- University of Rennes, CHU Rennes, Inserm, EHESP, IRSET (Institut de recherche en santé, environnement et travail), Rennes, France
| | - Caroline B. Moore
- Mycology Reference Centre Manchester and Department of Infectious Diseases, Manchester University, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester, United Kingdom
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Cornelia Lass-Flörl
- European Excellence Center for Medical Mycology (ECMM), Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Austria
| | - Florian Reizine
- University of Rennes, CHU Rennes, Inserm, EHESP, IRSET (Institut de recherche en santé, environnement et travail), Rennes, France
- Medical Intensive Care Unit, Rennes University Hospital, Rennes, France
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Fungal Infection Group, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Norman Van Rhijn
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Fungal Infection Group, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Michael J. Bromley
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Fungal Infection Group, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Antonis Rokas
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Sara Gago
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Fungal Infection Group, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - on behalf of the ECMM CAPA Study Group
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- University of Rennes, CHU Rennes, Inserm, EHESP, IRSET (Institut de recherche en santé, environnement et travail), Rennes, France
- Division of Infectious Diseases, Medical University of Graz, Graz, Austria
- Biotech Med, Graz, Austria
- Mycology Reference Centre Manchester and Department of Infectious Diseases, Manchester University, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester, United Kingdom
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- European Excellence Center for Medical Mycology (ECMM), Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Austria
- Medical Intensive Care Unit, Rennes University Hospital, Rennes, France
- Manchester Fungal Infection Group, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
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29
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Du W, Xu R, He Z, Yang H, Gu Y, Liu Y. Transcriptomics-based investigation of molecular mechanisms underlying synergistic antimicrobial effects of AgNPs and Domiphen on the human fungal pathogen Aspergillus fumigatus. Front Microbiol 2023; 14:1089267. [PMID: 36819018 PMCID: PMC9928863 DOI: 10.3389/fmicb.2023.1089267] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/12/2023] [Indexed: 02/04/2023] Open
Abstract
Critically ill patients have higher risk of serious fungal infections, such as invasive aspergillosis (IA) which is mainly caused by the human fungal pathogen Aspergillus fumigatus. Triazole drugs are the primary therapeutic agents for the first-line treatment of IA, which could easily cause drug resistance problems. Here, we assess the potential of AgNPs synthesized with Artemisia argyi leaf extract and domiphen as new antifungal agents to produce synergistic antimicrobial effects on Aspergillus fumigatus, and dissect possible molecular mechanisms of action. Plate inoculation assays combined with drug susceptibility test and cytotoxicity test showed that the combination of AgNPs and domiphen has synergistic antimicrobial effects on A. fumigatus with low cytotoxicity. Gene Ontology (GO) enrichment analysis showed that AgNPs and domiphen inhibit the growth of A. fumigatus by suppressing nitrate assimilation, and purine nucleobase metabolic process and amino acid transmembrane transport, respectively. When the two drugs are combined, AgNPs has epistatic effects on domiphen. Moreover, the combination of AgNPs and domiphen primarily influence secondary metabolites biosynthesis, steroid biosynthesis and nucleotide sugar metabolism of A. fumigatus via Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Furthermore, protein-protein interactions (PPI) analysis combined with validation experiments showed that the combination of AgNPs and domiphen could enhance the expression of copper transporter and inhibit nitrogen source metabolism. In addition, the synergistic antimicrobial effects could be enhanced or eliminated depending on exogenous addition of copper and nitrogen source, respectively. Taken together, the results of this study provide a theoretical basis and a new strategy for the treatment of IA.
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Affiliation(s)
- Wenlong Du
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,*Correspondence: Wenlong Du, ✉
| | - Ruolin Xu
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Zhiqiang He
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Huan Yang
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yufan Gu
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yi Liu
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China,Yi Liu, ✉
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PU.1-CD23 signaling mediates pulmonary innate immunity against Aspergillus fumigatus infection by driving inflammatory response. BMC Immunol 2023; 24:4. [PMID: 36650424 PMCID: PMC9844028 DOI: 10.1186/s12865-023-00539-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 01/03/2023] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Aspergillosis is a common cause of morbidity and mortality in immunocompromised populations. PU.1 is critical for innate immunity against Aspergillus fumigatus (AF) in macrophages. However, the molecular mechanism underlying PU.1 mediating immunity against AF infection in human alveolar macrophages (AMs) is still unclear. METHODS In this study, we detected the expressions of PU.1, CD23, p-ERK, CCL20 and IL-8 and key inflammatory markers IL-1β, IL-6, TNF-α and IL-12 in human THP-1-derived macrophages (HTMs) or PU.1/CD23-overexpressed immunodeficient mice with AF infection. Moreover, we examined these expressions in PU.1-overexpressed/interfered HTMs. Additionally, we detected the phagocytosis of macrophages against AF infection with altered PU.1 expression. Dual luciferase, ChIP and EMSAs were performed to detect the interaction of PU.1 and CD23. And we invested the histological changes in mouse lung tissues transfected with PU.1/CD23-expressing adenoviruses in AF infection. RESULTS The results showed that the expressions of PU.1, CD23, p-ERK, CCL20, IL-8, IL-1β, IL-6, TNF-α and IL-12 increased significantly with AF infection, and PU.1 regulated the later 8 gene expressions in HTMs. Moreover, CD23 was directly activated by PU.1, and overexpression of CD23 in PU.1-interfered HTMs upregulated IL-1β, IL-6, TNF-α and IL-12 levels which were downregulated by PU.1 interference. PU.1 overexpression strengthened the phagocytosis of the HTMs against AF. And injection of PU.1/CD23-expressing adenoviruses attenuated pathological defects in immunodeficient mouse lung tissues with AF infection. Adenovirus (Ad)-PU.1 increased the CD23, p-ERK, CCL20, IL-8 levels. CONCLUSIONS Our study concluded that PU.1-CD23 signaling mediates innate immunity against AF in lungs through regulating inflammatory response. Therefore, PU.1-CD23 may be a new anti-aspergillosis therapeutic for the treatment of invasive aspergillosis with the deepening of gene therapy and its wide application in the clinic.
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Kim KH, Kang S, Seo H, Yun CW. AfSec1 is a signal peptidase and removes signal peptides of 1,3-β-glucanosyltransferases in Aspergillus fumigatus. Med Mycol 2022; 61:6993075. [PMID: 36657388 DOI: 10.1093/mmy/myad005] [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: 09/28/2022] [Revised: 01/11/2023] [Accepted: 01/18/2023] [Indexed: 01/20/2023] Open
Abstract
To identify the infection mechanism of Aspergillus fumigatus, which is an opportunistic fungal pathogen, we analyzed the expression profile of the whole genome of A. fumigatus during the infection of murine macrophages. A previously reported RNA-seq data analysis showed that many genes involved in cell wall synthesis were upregulated during the infection process. Interestingly, AfSec1 (3g12840), which encodes a putative signal peptidase, was upregulated dramatically, and its putative target protein Gel1, which encodes a 1,3-β-glucanosyltransferase, was also upregulated. Instead of the AfSec1 deletion strain, the AfSec1-ΔP strain was constructed, in which the promoter region of AfSec1 was deleted, and AfSec1 expression was not detected in the AfSec1-ΔP strain. The expression of AfSec1 was recovered by the introduction of the promoter region (the AfSec1-ΔP/P strain). The nonprocessed form of Gel1 was identified in the AfSec1-ΔP strain, which lacked the promoter, but mature forms of Gel1 were found in the wild-type and in AfSec1-ΔP/P, which was the promoter complementation strain. In the plate assay, the AfSec1-ΔP strain showed higher sensitivity against caspofungin than the wild-type. However, compared with the wild-type, the deletion strain showed no difference in the sensitivity to other antifungal drugs, such as amphotericin B and voriconazole, which inhibit different targets compared with caspofungin. The AfSec1-ΔP strain exhibited ∼20% lower levels of β-glucan in the cell wall than the wild-type. Finally, the virulence decreased when the promoter region of AfSec1 was deleted, as observed in the murine infection test and conidia-killing assay using human macrophages and neutrophils. These results suggest that AfSec1 exerts signal peptidase activity on its target Gel1 and has an important role in fungal pathogenesis.
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Affiliation(s)
- Ki-Hwan Kim
- School of Life Sciences and Biotechnology, Korea University Anam-dong, Sungbuk-gu, Seoul, Republic of Korea
| | - Suzie Kang
- School of Life Sciences and Biotechnology, Korea University Anam-dong, Sungbuk-gu, Seoul, Republic of Korea
| | - Hyewon Seo
- School of Life Sciences and Biotechnology, Korea University Anam-dong, Sungbuk-gu, Seoul, Republic of Korea
| | - Cheol-Won Yun
- School of Life Sciences and Biotechnology, Korea University Anam-dong, Sungbuk-gu, Seoul, Republic of Korea.,NeuroEsgel Co., Anam-dong, Sungbuk-gu, Seoul, 02841, Korea
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Hatmaker EA, Rangel-Grimaldo M, Raja HA, Pourhadi H, Knowles SL, Fuller K, Adams EM, Lightfoot JD, Bastos RW, Goldman GH, Oberlies NH, Rokas A. Genomic and Phenotypic Trait Variation of the Opportunistic Human Pathogen Aspergillus flavus and Its Close Relatives. Microbiol Spectr 2022; 10:e0306922. [PMID: 36318036 PMCID: PMC9769809 DOI: 10.1128/spectrum.03069-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Fungal diseases affect millions of humans annually, yet fungal pathogens remain understudied. The mold Aspergillus flavus can cause both aspergillosis and fungal keratitis infections, but closely related species are not considered clinically relevant. To study the evolution of A. flavus pathogenicity, we examined genomic and phenotypic traits of two strains of A. flavus and three closely related species, Aspergillus arachidicola (two strains), Aspergillus parasiticus (two strains), and Aspergillus nomiae (one strain). We identified >3,000 orthologous proteins unique to A. flavus, including seven biosynthetic gene clusters present in A. flavus strains and absent in the three nonpathogens. We characterized secondary metabolite production for all seven strains under two clinically relevant conditions, temperature and salt concentration. Temperature impacted metabolite production in all species, whereas salinity did not affect production of any species. Strains of the same species produced different metabolites. Growth under stress conditions revealed additional heterogeneity within species. Using the invertebrate fungal disease model Galleria mellonella, we found virulence of strains of the same species varied widely; A. flavus strains were not more virulent than strains of the nonpathogens. In a murine model of fungal keratitis, we observed significantly lower disease severity and corneal thickness for A. arachidicola compared to other species at 48 h postinfection, but not at 72 h. Our work identifies variations in key phenotypic, chemical, and genomic attributes between A. flavus and its nonpathogenic relatives and reveals extensive strain heterogeneity in virulence that does not correspond to the currently established clinical relevance of these species. IMPORTANCE Aspergillus flavus is a filamentous fungus that causes opportunistic human infections, such as aspergillosis and fungal keratitis, but its close relatives are considered nonpathogenic. To begin understanding how this difference in pathogenicity evolved, we characterized variation in infection-relevant genomic, chemical, and phenotypic traits between strains of A. flavus and its relatives. We found extensive variation (or strain heterogeneity) within the pathogenic A. flavus as well as within its close relatives, suggesting that strain-level differences may play a major role in the ability of these fungi to cause disease. Surprisingly, we also found that the virulence of strains from species not considered to be pathogens was similar to that of A. flavus in both invertebrate and murine models of disease. These results contrast with previous studies on Aspergillus fumigatus, another major pathogen in the genus, for which significant differences in infection-relevant chemical and phenotypic traits are observed between closely related pathogenic and nonpathogenic species.
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Affiliation(s)
- E. Anne Hatmaker
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Manuel Rangel-Grimaldo
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Huzefa A. Raja
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Hadi Pourhadi
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Sonja L. Knowles
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Kevin Fuller
- Department of Microbiology and Immunology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - Emily M. Adams
- Department of Microbiology and Immunology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - Jorge D. Lightfoot
- Department of Microbiology and Immunology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - Rafael W. Bastos
- Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Nicholas H. Oberlies
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
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Fungal Zinc Homeostasis and Its Potential as an Antifungal Target: A Focus on the Human Pathogen Aspergillus fumigatus. Microorganisms 2022; 10:microorganisms10122469. [PMID: 36557722 PMCID: PMC9785309 DOI: 10.3390/microorganisms10122469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic airborne fungus that causes severe invasive aspergillosis in immunocompromised patients. Zinc is an essential micronutrient for the growth of A. fumigatus and even for all microorganisms. An increasing number of studies have reported that fungal zinc acquisition ability plays a key role in fungal survival in hosts with an extremely zinc-limited microenvironment. The ability to fight scarcity and excess of zinc are tightly related to fungal virulence and may be used as new potential targets. Because the regulation of zinc homeostasis is important, a thorough understanding of the functional genes involved in the regulatory network for zinc homeostasis is required for fungal pathogens. The current mini-review summarized potential zinc homeostasis regulators in A. fumigatus and classified these regulators according to localization and function, which were identified or predicted based on A. fumigatus or deduced from homologs in model yeasts. Future perspectives for zinc homeostasis regulators as potential antifungal targets to treat invasive aspergillosis are also discussed.
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Emri T, Antal K, Gila B, Jónás AP, Pócsi I. Stress Responses Elicited by Glucose Withdrawal in Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8111226. [PMID: 36422047 PMCID: PMC9692504 DOI: 10.3390/jof8111226] [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: 10/21/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Glucose is a widely used carbon source in laboratory practice to culture Aspergillus fumigatus, however, glucose availability is often low in its “natural habitats”, including the human body. We used a physiological−transcriptomical approach to reveal differences between A. fumigatus Af293 cultures incubated on glucose, glucose and peptone, peptone (carbon limitation), or without any carbon source (carbon starvation). Autolytic cell wall degradation was upregulated by both carbon starvation and limitation. The importance of autolytic cell wall degradation in the adaptation to carbon stress was also highlighted by approximately 12.4% of the A. fumigatus genomes harboring duplication of genes involved in N-acetyl glucosamine utilization. Glucose withdrawal increased redox imbalance, altered both the transcription of antioxidative enzyme genes and oxidative stress tolerance, and downregulated iron acquisition, but upregulated heme protein genes. Transcriptional activity of the Gliotoxin cluster was low in all experiments, while the Fumagillin cluster showed substantial activity both on glucose and under carbon starvation, and the Hexadehydro-astechrome cluster only on glucose. We concluded that glucose withdrawal substantially modified the physiology of A. fumigatus, including processes that contribute to virulence. This may explain the challenge of predicting the in vivo behavior of A. fumigatus based on data from glucose rich cultures.
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Affiliation(s)
- Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Egyetem tér 1, 4032 Debrecen, Hungary
- Correspondence:
| | - Károly Antal
- Department of Zoology, Eszterházy Károly Catholic University, Eszterházy tér 1, 3300 Eger, Hungary
| | - Barnabás Gila
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Andrea P. Jónás
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Egyetem tér 1, 4032 Debrecen, Hungary
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Shende R, Wong SSW, Meitei HT, Lal G, Madan T, Aimanianda V, Pal JK, Sahu A. Protective role of host complement system in Aspergillus fumigatus infection. Front Immunol 2022; 13:978152. [PMID: 36211424 PMCID: PMC9539816 DOI: 10.3389/fimmu.2022.978152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 09/05/2022] [Indexed: 11/25/2022] Open
Abstract
Invasive aspergillosis (IA) is a life-threatening fungal infection for immunocompromised hosts. It is, therefore, necessary to understand the immune pathways that control this infection. Although the primary infection site is the lungs, aspergillosis can disseminate to other organs through unknown mechanisms. Herein we have examined the in vivo role of various complement pathways as well as the complement receptors C3aR and C5aR1 during experimental systemic infection by Aspergillus fumigatus, the main species responsible for IA. We show that C3 knockout (C3-/-) mice are highly susceptible to systemic infection of A. fumigatus. Intriguingly, C4-/- and factor B (FB)-/- mice showed susceptibility similar to the wild-type mice, suggesting that either the complement pathways display functional redundancy during infection (i.e., one pathway compensates for the loss of the other), or complement is activated non-canonically by A. fumigatus protease. Our in vitro study substantiates the presence of C3 and C5 cleaving proteases in A. fumigatus. Examination of the importance of the terminal complement pathway employing C5-/- and C5aR1-/- mice reveals that it plays a vital role in the conidial clearance. This, in part, is due to the increased conidial uptake by phagocytes. Together, our data suggest that the complement deficiency enhances the susceptibility to systemic infection by A. fumigatus.
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Affiliation(s)
- Rajashri Shende
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule (S. P.) Pune University Campus, Pune, India
- Dr. D.Y. Patil Biotechnology & Bioinformatics Institute, Dr. D.Y. Patil Vidyapeeth, Pune, India
| | - Sarah Sze Wah Wong
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Unité Mycologie Moléculaire, Department of Mycology, Paris, France
| | - Heikrujam Thoihen Meitei
- Laboratory of Autoimmunity and Tolerance, National Centre for Cell Science, Savitribai Phule (S. P.) Pune University Campus, Pune, India
| | - Girdhari Lal
- Laboratory of Autoimmunity and Tolerance, National Centre for Cell Science, Savitribai Phule (S. P.) Pune University Campus, Pune, India
| | - Taruna Madan
- Department of Innate Immunity, ICMR – National Institute for Research in Reproductive and Child Health, Mumbai, India
| | - Vishukumar Aimanianda
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Unité Mycologie Moléculaire, Department of Mycology, Paris, France
- *Correspondence: Arvind Sahu, ; Vishukumar Aimanianda,
| | - Jayanta Kumar Pal
- Dr. D.Y. Patil Biotechnology & Bioinformatics Institute, Dr. D.Y. Patil Vidyapeeth, Pune, India
| | - Arvind Sahu
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule (S. P.) Pune University Campus, Pune, India
- *Correspondence: Arvind Sahu, ; Vishukumar Aimanianda,
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Emri T, Sümegi-Győri VM, Páll K, Gila BC, Pócsi I. Effect of the combinatorial iron-chelation and oxidative stress on the growth of Aspergillus species. Res Microbiol 2022; 173:103969. [PMID: 35863560 DOI: 10.1016/j.resmic.2022.103969] [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: 02/22/2022] [Revised: 06/20/2022] [Accepted: 07/07/2022] [Indexed: 10/17/2022]
Abstract
The growth of 14 Aspergillus strains belonging to nine species was studied under combinatorial deferriprone - H2O2 (iron-chelation - oxidative) stress. When deferriprone pretreated mycelia were subjected to even a weak oxidative stress, the growth inhibitory effect of iron-chelation stress was enhanced in 10 out of 14 strains. In contrast, oxidative stress pretreatment of conidia increased their deferriprone tolerance in 10 strains. Applying iron-chelators as antifungal agent or adjuvant can enhance the efficiency of the combinatorial iron withdrawal - oxidative stress strategy of our immune system and may reduce the survival of conidia escaped from the oxidative attack of pulmonary macrophages.
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Affiliation(s)
- Tamás Emri
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem Tér 1, 4032 Debrecen, Hungary.
| | - Veronika M Sümegi-Győri
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem Tér 1, 4032 Debrecen, Hungary.
| | - Krisztián Páll
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem Tér 1, 4032 Debrecen, Hungary.
| | - Barnabás Cs Gila
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem Tér 1, 4032 Debrecen, Hungary.
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem Tér 1, 4032 Debrecen, Hungary.
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Garstka K, Hecel A, Kozłowski H, Rowińska-Żyrek M. Specific Zn(II)-binding site in the C-terminus of Aspf2, a zincophore from Aspergillus fumigatus. Metallomics 2022; 14:6608364. [PMID: 35700143 PMCID: PMC9780748 DOI: 10.1093/mtomcs/mfac042] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/23/2022] [Indexed: 12/27/2022]
Abstract
Aspergillus fumigatus, one of the most widespread opportunistic human fungal pathogens, adapts to zinc limitation by secreting a 310 amino acid Aspf2 zincophore, able to specifically bind Zn(II) and deliver it to a transmembrane zinc transporter, ZrfC. In this work, we focus on the thermodynamics of Zn(II) complexes with unstructured regions of Aspf2; basing on a variety of spectrometric and potentiometric data, we show that the C-terminal part has the highest Zn(II)-binding affinity among the potential binding sites, and Ni(II) does not compete with Zn(II) binding to this region. The 14 amino acid Aspf2 C-terminus coordinates Zn(II) via two Cys thiolates and two His imidazoles and it could be considered as a promising A. fumigatus targeting molecule.
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Affiliation(s)
- Kinga Garstka
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Aleksandra Hecel
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Henryk Kozłowski
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland,Institute of Health Sciences, University of Opole, Katowicka 68 St, 45-060 Opole, Poland
| | - Magdalena Rowińska-Żyrek
- Correspondence: Magdalena Rowińska-Żyrek, Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland. E-mail:
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Biologia futura: combinatorial stress responses in fungi. Biol Futur 2022; 73:207-217. [DOI: 10.1007/s42977-022-00121-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 05/13/2022] [Indexed: 10/18/2022]
Abstract
AbstractIn the ever-changing fungal environment, fungi have to cope with a wide array of very different stresses. These stresses frequently act in combination rather than independently, i.e., they quickly follow one another or occur concomitantly. Combinatorial stress response studies revealed that the response of fungi to a stressor is highly dependent on the simultaneous action of other stressors or even on earlier stresses to which the fungi adapted. Several important phenomena were discovered, such as stress pathway interference, acquired stress tolerance, stress response memory or stress cross-protection/sensitization, which cannot be interpreted when we study the consequences of a single stressor alone. Due to the interactions between stressors and stress responses, a stress response that develops under a combined stress is not the simple summation of stress responses observed during single stress treatments. Based on the knowledge collected from single stress treatment experiments, we cannot predict how fungi will respond to a certain combination of stresses or even whether this combination will be more harmful than single stress treatments. This uncertainty warns us that if we want to understand how fungi adapt to a certain habitat (e.g., to the human body) to find a point of weakness in this adaptation, we must understand how the fungi cope with combinations of stresses, rather than with single stressors.
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The Multifaceted Role of Mating Type of the Fungus and Sex of the Host in Studies of Fungal Infections in Humans. J Fungi (Basel) 2022; 8:jof8050461. [PMID: 35628717 PMCID: PMC9145136 DOI: 10.3390/jof8050461] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/27/2022] [Accepted: 04/27/2022] [Indexed: 02/04/2023] Open
Abstract
This review discusses the inclusion of sex and gender variables in studies of fungal infections in humans at the pathogen, host, and antifungal trial levels. The mating type of some fungi, or perhaps more likely the absence of the other, appears to be associated with some infections. Sexual and parasexual reproduction of some fungi is an important mechanism for the development of antifungal drug resistance. Host sex or gender influences the incidence of some infections such as aspergillosis, cryptococcosis, paracoccidioidomycosis, dermatophytosis, and candidiasis due to differences in immune response, behavior, and awareness for early detection and treatment. Participant sex (and age) is relevant not only in clinical antifungal trials but also in preclinical studies. The dimensions of sex and gender are important determinants throughout the fungal infection process and in approaches to prevent or treat these infections, as well as in development of antifungal drugs. Failure to consider sex and gender may be detrimental to the holistic understanding of the processes involved in fungal infection.
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Calero AL, Alonso R, Gadea I, Vega MDM, García MM, Muñoz P, Machado M, Bouza E, García-Rodríguez J. Comparison of the Performance of Two Galactomannan Detection Tests: Platelia Aspergillus Ag and Aspergillus Galactomannan Ag Virclia Monotest. Microbiol Spectr 2022; 10:e0262621. [PMID: 35262395 PMCID: PMC9045373 DOI: 10.1128/spectrum.02626-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/11/2022] [Indexed: 12/14/2022] Open
Abstract
The use of nonculture-based biomarkers such as the determination of galactomannan is sought for the diagnosis of invasive aspergillosis. To investigate the comparative yield of two tests for the detection of galactomannan in patients with or without proven or probable invasive aspergillosis. Overall, 327 samples (327 patients) were analyzed in a retrospective/prospective study performed in 3 hospitals in Madrid, comparing the determination results in serum or bronchoalveolar lavage of two techniques for galactomannan detection, namely, Platelia Aspergillus Ag (Bio-Rad) and Aspergillus galactomannan Ag Virclia Monotest (Vircell S.L.), following the manufacturer's instructions. Both techniques can automate the process, but the second technique has the advantage of individual processing and assembly of each sample without the need for the additional expense of single-dose strips in controls. In total, 288 of the 327 tests performed showed concordant results between both techniques. The agreement between both methods was к = 0.722, and the correlation between indices was ρ = 0.718. Only 39 samples showed discordant results. In those 39 cases, there were 15 patients with proven or probable invasive aspergillosis criteria. For the samples with clinical criteria as a reference, the areas under the curve of the receiver operating characteristic (ROC) curve were 0.962 for Platelia and 0.968 for VirClia. The VirClia test has been proven to be an alternative for diagnosis due to its friendlier automated format than that of the usual Platelia routine test. The VirClia test also allows individual action and, therefore, a more immediate clinical response. IMPORTANCE Invasive mycoses are increasingly present in immunosuppressed or hospitalized patients with serious illnesses, leading to high rates of morbidity and mortality. Invasive aspergillosis is an infection caused, in a percentage greater than 50%, by the genus Aspergillus. It is vitally important to make an early diagnosis that leads to the application of antifungals in the initial stage of the infection. Therefore, tools are required to help with the early diagnosis of the infection. This comparative study of two enzyme immunoassays is based on the detection of galactomannan antigen in serum and bronchoalveolar lavage samples. A new design based on chemiluminescence and presented in an automated single-dose format is compared to a conventional ELISA technique marketed for years. The results obtained from the prospective and retrospective study indicate a high correlation and degree of agreement between both techniques, as well as in their diagnostic performance.
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Affiliation(s)
- Alba Leyva Calero
- Department of Biochemistry, Immunology and Molecular Parasitology, Universidad de Granada, Granada, Spain
| | - Roberto Alonso
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Biosanitaria Gregorio Marañón, Madrid, Spain
- CIBER de Enfermedades Respiratorias CIBERES, Barcelona, Spain
- Department of Medicine, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Ignacio Gadea
- Department of Clinical Microbiology, Fundación Jimenez Díaz, Autonomous University, Madrid, Spain
| | | | - Marta Martín García
- Department of Clinical Microbiology, Fundación Jimenez Díaz, Autonomous University, Madrid, Spain
| | - Patricia Muñoz
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Biosanitaria Gregorio Marañón, Madrid, Spain
- CIBER de Enfermedades Respiratorias CIBERES, Barcelona, Spain
- Department of Medicine, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Marina Machado
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Biosanitaria Gregorio Marañón, Madrid, Spain
- CIBER de Enfermedades Respiratorias CIBERES, Barcelona, Spain
| | - Emilio Bouza
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Biosanitaria Gregorio Marañón, Madrid, Spain
- CIBER de Enfermedades Respiratorias CIBERES, Barcelona, Spain
- Department of Medicine, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Julio García-Rodríguez
- Department of Clinical Microbiology, Hospital La Paz, Autonomous University, Madrid, Spain
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de Oliveira Silva A, Aliyeva-Schnorr L, Wirsel SGR, Deising HB. Fungal Pathogenesis-Related Cell Wall Biogenesis, with Emphasis on the Maize Anthracnose Fungus Colletotrichum graminicola. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11070849. [PMID: 35406829 PMCID: PMC9003368 DOI: 10.3390/plants11070849] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/14/2022] [Accepted: 03/17/2022] [Indexed: 05/25/2023]
Abstract
The genus Colletotrichum harbors many plant pathogenic species, several of which cause significant yield losses in the field and post harvest. Typically, in order to infect their host plants, spores germinate, differentiate a pressurized infection cell, and display a hemibiotrophic lifestyle after plant invasion. Several factors required for virulence or pathogenicity have been identified in different Colletotrichum species, and adaptation of cell wall biogenesis to distinct stages of pathogenesis has been identified as a major pre-requisite for the establishment of a compatible parasitic fungus-plant interaction. Here, we highlight aspects of fungal cell wall biogenesis during plant infection, with emphasis on the maize leaf anthracnose and stalk rot fungus, Colletotrichum graminicola.
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Gupta L, Sen P, Bhattacharya AK, Vijayaraghavan P. Isoeugenol affects expression pattern of conidial hydrophobin gene RodA and transcriptional regulators MedA and SomA responsible for adherence and biofilm formation in Aspergillus fumigatus. Arch Microbiol 2022; 204:214. [PMID: 35314887 PMCID: PMC8938220 DOI: 10.1007/s00203-022-02817-w] [Citation(s) in RCA: 7] [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: 09/29/2021] [Revised: 02/01/2022] [Accepted: 02/24/2022] [Indexed: 11/25/2022]
Abstract
Aspergillus fumigatus is one of the major pathogenic fungal species, causing life-threatening infections. Due to a limited spectrum of available antifungals, exploration of new drug targets as well as potential antifungal molecules has become pertinent. Rodlet layer plays an important role in adherence of fungal conidia to hydrophobic cell surfaces in host, which also leads to A. fumigatus biofilm formation, contributing factor to fungal pathogenicity. From decades, natural sources have been known for the development of new active molecules. The present study investigates effect of isoeugenol on genes responsible for hydrophobins (RodA), adhesion as well as biofilm formation (MedA and SomA) of A. fumigatus. Minimum inhibitory concentrations (MIC and IC50) of isoeugenol against A. fumigatus were determined using broth microdilution assay. The IC50 results showed reduced hydrophobicity and biofilm formation as well as eradication after treatment with the compound and electron micrograph data corroborated these findings. The qRT-PCR showed a significant downregulation of genes RodA, MedA, SomA and pksP involved in hydrophobicity and biofilm formation. SwissADME studies potentiated drug-like propensity for isoeugenol which formed four hydrogen bonds with low binding energy (− 4.54 kcal/mol) at the catalytic site of RodA protein studied via AutoDock4. Hence, the findings conclude that isoeugenol inhibits conidial hydrophobicity and biofilm formation of A. fumigatus and further investigations are warranted in this direction.
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Affiliation(s)
- Lovely Gupta
- Antimycotic and Drug Susceptibility Laboratory, Lab 120, J3 block, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector-125, NOIDA, Uttar Pradesh, India
| | - Pooja Sen
- Antimycotic and Drug Susceptibility Laboratory, Lab 120, J3 block, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector-125, NOIDA, Uttar Pradesh, India
| | - Asish K Bhattacharya
- Division of Organic Chemistry, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Pooja Vijayaraghavan
- Antimycotic and Drug Susceptibility Laboratory, Lab 120, J3 block, Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector-125, NOIDA, Uttar Pradesh, India.
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Palmieri F, Koutsokera A, Bernasconi E, Junier P, von Garnier C, Ubags N. Recent Advances in Fungal Infections: From Lung Ecology to Therapeutic Strategies With a Focus on Aspergillus spp. Front Med (Lausanne) 2022; 9:832510. [PMID: 35386908 PMCID: PMC8977413 DOI: 10.3389/fmed.2022.832510] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/22/2022] [Indexed: 12/15/2022] Open
Abstract
Fungal infections are estimated to be the main cause of death for more than 1.5 million people worldwide annually. However, fungal pathogenicity has been largely neglected. This is notably the case for pulmonary fungal infections, which are difficult to diagnose and to treat. We are currently facing a global emergence of antifungal resistance, which decreases the chances of survival for affected patients. New therapeutic approaches are therefore needed to face these life-threatening fungal infections. In this review, we will provide a general overview on respiratory fungal infections, with a focus on fungi of the genus Aspergillus. Next, the immunological and microbiological mechanisms of fungal pathogenesis will be discussed. The role of the respiratory mycobiota and its interactions with the bacterial microbiota on lung fungal infections will be presented from an ecological perspective. Finally, we will focus on existing and future innovative approaches for the treatment of respiratory fungal infections.
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Affiliation(s)
- Fabio Palmieri
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- *Correspondence: Fabio Palmieri,
| | - Angela Koutsokera
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Eric Bernasconi
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Christophe von Garnier
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Niki Ubags
- Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
- Niki Ubags,
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Margalit A, Sheehan D, Carolan JC, Kavanagh K. Exposure to the Pseudomonas aeruginosa secretome alters the proteome and secondary metabolite production of Aspergillus fumigatus. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001164. [PMID: 35333152 PMCID: PMC9558348 DOI: 10.1099/mic.0.001164] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/16/2022] [Indexed: 01/09/2023]
Abstract
The fungal pathogen Aspergillus fumigatus is frequently cultured from the sputum of cystic fibrosis (CF) patients along with the bacterium Pseudomonas aeruginosa. A. fumigatus secretes a range of secondary metabolites, and one of these, gliotoxin, has inhibitory effects on the host immune response. The effect of P. aeruginosa culture filtrate (CuF) on fungal growth and gliotoxin production was investigated. Exposure of A. fumigatus hyphae to P. aeruginosa cells induced increased production of gliotoxin and a decrease in fungal growth. In contrast, exposure of A. fumigatus hyphae to P. aeruginosa CuF led to increased growth and decreased gliotoxin production. Quantitative proteomic analysis was used to characterize the proteomic response of A. fumigatus upon exposure to P. aeruginosa CuF. Changes in the profile of proteins involved in secondary metabolite biosynthesis (e.g. gliotoxin, fumagillin, pseurotin A), and changes to the abundance of proteins involved in oxidative stress (e.g. formate dehydrogenase) and detoxification (e.g. thioredoxin reductase) were observed, indicating that the bacterial secretome had a profound effect on the fungal proteome. Alterations in the abundance of proteins involved in detoxification and oxidative stress highlight the ability of A. fumigatus to differentially regulate protein synthesis in response to environmental stresses imposed by competitors such as P. aeruginosa. Such responses may ultimately have serious detrimental effects on the host.
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Affiliation(s)
- Anatte Margalit
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - David Sheehan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - James C. Carolan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Co. Kildare, Ireland
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Dhabaan G, Kus J, Kumar D, Humar A, Husain S, Mazzulli T. Molecular identification of Aspergillus fumigatus complex from lung transplant recipients using multilocus sequencing analysis (MLSA). JOURNAL OF THE ASSOCIATION OF MEDICAL MICROBIOLOGY AND INFECTIOUS DISEASE CANADA = JOURNAL OFFICIEL DE L'ASSOCIATION POUR LA MICROBIOLOGIE MEDICALE ET L'INFECTIOLOGIE CANADA 2022; 7:54-63. [PMID: 36340850 PMCID: PMC9603012 DOI: 10.3138/jammi-2021-0004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 10/20/2021] [Accepted: 10/30/2021] [Indexed: 06/16/2023]
Abstract
BACKGROUND Aspergillus infection causes significant morbidity and mortality among lung transplant recipients (LTRs). It is primarily caused by Aspergillus fumigatus. Other closely related species belonging to the section Fumigati have also been found. These cryptic species are often misidentified as A. fumigatus. Thus, we used multilocus sequencing analysis (MLSA) of the calmodulin, β-tubulin, and hydrophobin gene sequences to identify these species and to determine the frequency with which they occur among LTRs. METHODS A total of 81 A. fumigatus isolates were initially isolated from bronchoalveolar lavage fluid or sputum specimens collected from lung transplant patients. These isolates were then sub-cultured and genotyped using MLSA. Of these isolates, 53, 17, and 11 were isolated from double LTRs, single LTRs, and pre-LTRs, respectively. RESULTS All isolates (100%) carried DNA sequences identical to those of A. fumigatus reference strains and thus clustered in the same clade with A. fumigatus. Analysis of the MLSA data revealed that A. fumigatus species were the only species recovered in this population of LTRs. The MLSA results were consistent with those routinely obtained by conventional mycological procedures in the microbiology laboratory. CONCLUSIONS A. fumigatus appears to be the primary causative agent of colonization or invasive aspergillosis among LTRs. No cryptic species were identified.
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Affiliation(s)
- Ghulam Dhabaan
- Department of Microbiology, Sinai Health System/University Health Network, Toronto, Ontario, Canada
- Division of Infectious Diseases, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Public Health of Ontario Laboratory, Toronto, Ontario, Canada
| | - Julianne Kus
- Public Health of Ontario Laboratory, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Deepali Kumar
- Division of Infectious Diseases, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Atul Humar
- Division of Infectious Diseases, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Shahid Husain
- Division of Infectious Diseases, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Tony Mazzulli
- Department of Microbiology, Sinai Health System/University Health Network, Toronto, Ontario, Canada
- Public Health of Ontario Laboratory, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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Song J, Shi L, Wang S, Wang Y, Zhu Y, Jiang J, Li R. Acidic/Alkaline Stress Mediates Responses to Azole Drugs and Oxidative Stress in Aspergillus fumigatus. Microbiol Spectr 2022; 10:e0199921. [PMID: 35196814 PMCID: PMC8865478 DOI: 10.1128/spectrum.01999-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/19/2022] [Indexed: 11/20/2022] Open
Abstract
A human host exploits stresses such as acidic/alkaline pH, antifungal drugs, and reactive oxygen species to kill microbial pathogens such as the fungus Aspergillus fumigatus. However, A. fumigatus is resistant to these stresses in vitro. Therefore, what accounts for the potent antifungal activity of the human host? In this observation, we show that simultaneous exposure to acidic pH and oxidative stresses is much more potent than the individual stresses themselves and that this combinatorial stress kills A. fumigatus synergistically in vitro. Interestingly, A. fumigatus is resistant to the combination of alkaline pH and oxidative stress. Quantitative real-time PCR analyses showed that acidic/alkaline pH stress can mediate oxidative stress responses in A. fumigatus by regulating the expression of catalase-encoding genes. We further show that A. fumigatus is sensitive to the combination of acidic/alkaline stress and azole drug stress. Transcriptome analysis revealed that the sensitivity of A. fumigatus to azole drugs under acidic/alkaline conditions may be related to changes in genetic stability, sphingolipid metabolism, lipid metabolism, and amino acid metabolism. Collectively, our findings suggest that combinatorial stress represents a powerful fungicidal mechanism employed by hosts against pathogens, which suggests novel approaches to potentiate antifungal therapy. IMPORTANCE The human host combats fungal infections via phagocytic cells that recognize and kill fungal pathogens. Immune cells combat Aspergillus fumigatus infections with a potent mixture of chemicals, including reactive oxygen species, acidic/alkaline stress, and antifungal drugs. However, A. fumigatus is relatively resistant to these stresses in vitro. In this observation, we show that it is the combination of acidic/alkaline pH and oxidative or azole stress that kills A. fumigatus so effectively, and we define the molecular mechanisms that underlie this potency. Our findings suggest that combinatorial stress is a powerful fungicidal mechanism employed by hosts, which suggests novel approaches to potentiate antifungal therapy. This study provides a platform for future studies that will address the combinatorial impacts of various environmental stresses on A. fumigatus and other pathogenic microbes.
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Affiliation(s)
- Jinxing Song
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Landan Shi
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Sha Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou Central Hospital, Huzhou University, Huzhou, Zhejiang, China
| | - Yunqiu Wang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Yi Zhu
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Jihong Jiang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Rongpeng Li
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, China
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Guirao-Abad JP, Weichert M, Askew DS. Cell death induction in Aspergillus fumigatus: accentuating drug toxicity through inhibition of the unfolded protein response (UPR). CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100119. [PMID: 35909601 PMCID: PMC9325865 DOI: 10.1016/j.crmicr.2022.100119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/25/2022] [Accepted: 02/17/2022] [Indexed: 01/18/2023] Open
Abstract
The UPR is an adaptive stress response network that is tightly linked to the ability of Aspergillus fumigatus, and other pathogenic fungi, to sustain viability in the presence of adverse environmental conditions, including the stress of infection. In this review, we summarize the evidence that supports the concept of targeting the A. fumigatus UPR as a strategy to reduce the ability of the fungus to withstand stress.
One of the most potent opportunistic fungal pathogens of humans is Aspergillus fumigatus, an environmental mold that causes a life-threatening pneumonia with a high rate of morbidity and mortality. Despite advances in therapy, issues of drug toxicity and antifungal resistance remain an obstacle to effective therapy. This underscores the need for more information on fungal pathways that could be pharmacologically manipulated to either reduce the viability of the fungus during infection, or to unleash the fungicidal potential of current antifungal drugs. In this review, we summarize the emerging evidence that the ability of A. fumigatus to sustain viability during stress relies heavily on an adaptive signaling pathway known as the unfolded protein response (UPR), thereby exposing a vulnerability in this fungus that has strong potential for future therapeutic intervention.
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Nguyen S, Jovcevski B, Pukala TL, Bruning JB. Structural insights into the antifungal drug target guanosine monophosphate synthase from Aspergillus fumigatus. ACTA CRYSTALLOGRAPHICA SECTION D STRUCTURAL BIOLOGY 2022; 78:248-259. [DOI: 10.1107/s2059798321012031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/11/2021] [Indexed: 11/10/2022]
Abstract
Purine biosynthesis is a fundamental cellular process that sustains life by maintaining the intracellular pool of purines for DNA/RNA synthesis and signal transduction. As an integral determinant of fungal survival and virulence, the enzymes in this metabolic pathway have been pursued as potential antifungal targets. Guanosine monophosphate (GMP) synthase has been identified as an attractive target as it is essential for virulence in the clinically prominent fungal pathogens Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. However, a lack of structural information on GMP synthase has hindered drug-design efforts. Here, the first structure of a GMP synthase of fungal origin, that from A. fumigatus (at 2.3 Å resolution), is presented. Structural analysis of GMP synthase shows a distinct absence of the D1 dimerization domain that is present in the human homologue. Interestingly, A. fumigatus GMP synthase adopts a dimeric state, as determined by native mass spectrometry and gel-filtration chromatography, in contrast to the monomeric human homologue. Analysis of the substrate-binding pockets of A. fumigatus GMP synthase reveals key differences in the ATP- and XMP-binding sites that can be exploited for species-specific inhibitor drug design. Furthermore, the inhibitory activities of the glutamine analogues acivicin (IC50 = 16.6 ± 2.4 µM) and 6-diazo-5-oxo-L-norleucine (IC50 = 29.6 ± 5.6 µM) against A. fumigatus GMP synthase are demonstrated. Together, these data provide crucial structural information required for specifically targeting A. fumigatus GMP synthase for future antifungal drug-discovery endeavours.
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Abstract
Aspergillus flavusaflR, a gene encoding a Zn(II)2Cys6 DNA-binding domain, is an important transcriptional regulator of the aflatoxin biosynthesis gene cluster. Our previous results of Gene ontology (GO) analysis for the binding sites of AflR in A. flavus suggest that AflR may play an integrative regulatory role. In this study the ΔaflR and overexpression (OE) strains based on the well-established double-crossover recombinational technique were constructed to investigate the integrative function of the aflR gene in A. flavus. The disruption of aflR severely affected the aflatoxin biosynthetic pathway, resulting in a significant decrease in aflatoxin production. The aflatoxin B1 (AFB1) of the ΔaflR strain was 180 ng/mL and aflatoxin B2 (AFB2) was 2.95 ng/mL on YES medium for 5 days, which was 1/1,000 of that produced by the wild-type strain (WT). In addition, the ΔaflR strain produced relatively sparse conidia and a very small number of sclerotia. On the seventh day, the sclerotia yield on each plate of the WT and OE strains exceeded 1,000, while the sclerotial formation of the ΔaflR strain was not detected until 14 days. However, the biosynthesis of cyclopiazonic acid (CPA) was not affected by aflR gene disruption. Transcriptomic analysis of the ΔaflR strain grown on potato dextrose agar (PDA) plates at 0 h, 24 h, and 72 h showed that expression of clustering genes involved in the biosynthesis of aflatoxin was significantly downregulated. Meanwhile, the ΔaflR strain compared with the WT strain showed significant expression differences in genes involved in spore germination, sclerotial development, and carbohydrate metabolism compared to the WT. The results demonstrated that the A. flavusaflR gene also played a positive role in the fungal growth and development in addition to aflatoxin biosynthesis. IMPORTANCE Past studies of the A. flavusaflR gene and its orthologues in related Aspergillus species were solely focused on their roles in secondary metabolism. In this study, we used the ΔaflR and OE strains to demonstrate the role of aflR in growth and development of A. flavus. For the first time, we confirmed that the ΔaflR strain also was defective in production of conidia and sclerotia, asexual propagules of A. flavus. Our transcriptomic analysis further showed that genes involved in spore germination, sclerotial development, aflatoxin biosynssssthesis, and carbohydrate metabolism exhibited significant differences in the ΔaflR strain compared with the WT strain. Our study indicates that AflR not only plays an important role in regulating aflatoxin synthesis but also in playing a positive role in the conidial formation and sclerotial development in A. flavus. This study reveals the critical and positive role of the aflR gene in fungal growth and development, and provides a theoretical basis for the genetic studies of other aspergilli.
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The Gβ-like Protein AfCpcB Affects Sexual Development, Response to Oxidative Stress and Phagocytosis by Alveolar Macrophages in Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8010056. [PMID: 35049996 PMCID: PMC8777951 DOI: 10.3390/jof8010056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 12/17/2022] Open
Abstract
G-protein signaling is important for signal transduction, allowing various stimuli that are external to a cell to affect its internal molecules. In Aspergillus fumigatus, the roles of Gβ-like protein CpcB on growth, asexual development, drug sensitivity, and virulence in a mouse model have been previously reported. To gain a deeper insight into Aspergillus fumigatus sexual development, the ΔAfcpcB strain was generated using the supermater AFB62 strain and crossed with AFIR928. This cross yields a decreased number of cleistothecia, including few ascospores. The sexual reproductive organ-specific transcriptional analysis using RNAs from the cleistothecia (sexual fruiting bodies) indicated that the CpcB is essential for the completion of sexual development by regulating the transcription of sexual genes, such as veA, steA, and vosA. The ΔAfcpcB strain revealed increased resistance to oxidative stress by regulating genes for catalase, peroxiredoxin, and ergosterol biosynthesis. The ΔAfcpcB strain showed decreased uptake by alveolar macrophages in vitro, decreased sensitivity to Congo red, decreased expression of cell wall genes, and increased expression of the hydrophobin genes. Taken together, these findings indicate that AfCpcB plays important roles in sexual development, phagocytosis by alveolar macrophages, biosynthesis of the cell wall, and oxidative stress response.
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