1
|
Zakaria L. An Overview of Aspergillus Species Associated with Plant Diseases. Pathogens 2024; 13:813. [PMID: 39339004 PMCID: PMC11435247 DOI: 10.3390/pathogens13090813] [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: 06/19/2024] [Revised: 09/08/2024] [Accepted: 09/19/2024] [Indexed: 09/30/2024] Open
Abstract
The genus Aspergillus contains several species that are important plant pathogens. Plant pathogenic Aspergillus spp. affect agricultural crops in the field as well as after harvest, often associated with corn ear rot, cotton boll rot, peanut yellow mold, black mold of onion and garlic, fruit rot on grapes, pomegranates, olives, citrus, and apples. Coffee berries and coffee beans as well as tree nuts are also frequently infected by Aspergillus spp. Some of the plant pathogenic Aspergillus spp. are also mycotoxigenic, produced mycotoxin in the plant tissues leading to contamination of agricultural products. Over the years, reports of plant diseases caused by Aspergillus in various crops have increased, suggesting they are commonly encountered plant pathogens. This review focuses on agricultural crops or cultivated plants infected by Aspergillus spp. The compilation of plant pathogenic Aspergillus spp. provides information to mycologists, particularly those involved in plant pathology and crop protection, with updated information on plant diseases caused by various species of Aspergillus. The updated information also includes the locality or location, province, state and the country. The knowledge on the prevalence and geographic distribution of plant pathogenic Aspergillus spp. is beneficial in the application of crop protection.
Collapse
Affiliation(s)
- Latiffah Zakaria
- School of Biological Sciences, Universiti Sains Malaysia (USM), Penang 11800, Malaysia
| |
Collapse
|
2
|
Onoda Y, Nagahashi M, Yamashita M, Fukushima S, Aizawa T, Yamauchi S, Fujikawa Y, Tanaka T, Kadomura-Ishikawa Y, Ishida K, Uebanso T, Mawatari K, Blatchley ER, Takahashi A. Accumulated melanin in molds provides wavelength-dependent UV tolerance. Photochem Photobiol Sci 2024; 23:1791-1806. [PMID: 39287919 DOI: 10.1007/s43630-024-00632-4] [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: 05/01/2024] [Accepted: 09/02/2024] [Indexed: 09/19/2024]
Abstract
Fungal contamination poses a serious threat to public health and food safety because molds can grow under stressful conditions through melanin accumulation. Although ultraviolet (UV) irradiation is popular for inhibiting microorganisms, its effectiveness is limited by our insufficient knowledge about UV tolerance in melanin-accumulating molds. In this study, we first confirmed the protective effect of melanin by evaluating the UV sensitivity of young and mature spores. Additionally, we compared UV sensitivity between spores with accumulated melanin and spores prepared with melanin biosynthesis inhibitors. We found that mature spores were less UV-sensitive than young spores, and that reduced melanin accumulation by inhibitors led to reduced UV sensitivity. These results suggest that melanin protects cells against UV irradiation. To determine the most effective wavelength for inhibition, we evaluated the wavelength dependence of UV tolerance in a yeast (Rhodotorula mucilaginosa) and in molds (Aspergillus fumigatus, Cladosporium halotolerans, Cladosporium sphaerospermum, Aspergillus brasiliensis, Penicillium roqueforti, and Botrytis cinerea). We assessed UV tolerance using a UV-light emitting diode (LED) irradiation system with 13 wavelength-ranked LEDs between 250 and 365 nm, a krypton chlorine (KrCl) excimer lamp device, and a low pressure (LP) Hg lamp device. The inhibition of fungi peaked at around 270 nm, and most molds showed reduced UV sensitivity at shorter wavelengths as they accumulated pigment. Absorption spectra of the pigments showed greater absorption at shorter wavelengths, suggesting greater UV protection at these wavelengths. These results will assist in the development of fungal disinfection systems using UV, such as closed systems of air and water purification.
Collapse
Affiliation(s)
- Yushi Onoda
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Nichia Corporation, Anan, Tokushima, Japan
| | - Miharu Nagahashi
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | - Michiyo Yamashita
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | - Shiho Fukushima
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | | | | | | | | | - Yasuko Kadomura-Ishikawa
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | - Kai Ishida
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | - Takashi Uebanso
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | - Kazuaki Mawatari
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan
| | - Ernest R Blatchley
- Lyles School of Civil Engineering, Purdue University, 610 Purdue Mall, West Lafayette, IN, USA
- Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Akira Takahashi
- Department of Microbial Control, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan.
- Department of Preventive Environment and Nutrition, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Tokushima, Japan.
| |
Collapse
|
3
|
Suryanarayanan TS, Govindarajulu MB, Murali TS, Ravishankar JP, Bharathwaj S, Kalaiarasan MD. Amorosia littoralis Mantle & D. Hawksw. survives as root endophyte of mangroves and produces water soluble melanin pigment. Fungal Biol 2024; 128:1954-1959. [PMID: 39059850 DOI: 10.1016/j.funbio.2024.06.001] [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: 01/29/2024] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 07/28/2024]
Abstract
Melanins are heterogenous biopolymers produced by many macro and microorganisms. They enhance the ecological fitness of the producer organisms by improving their virulence and protecting them from radiation, osmotic and heat stresses. Fungi synthesise either DOPA or DHN melanin and deposit them on their cell walls. Some fungal isolates produce water soluble melanin (pyomelanin) which is excerted out of the hyphae into the surrounding environment. Pyomelanin, a polymer of homogentisate, exhibits antimicrobial, UV screening, antioxidative, and anti-inflammatory activities and recent studies also show that pyomelanin could find use in space travel as radiation shield. However, scant literature is available on fungi with ability to produce pyomelanin. We report for the first time that Amorosia littoralis occurs as a root endophyte in mangrove species including Avicennia marina, Bruguiera cylindrica and Bruguiera gymnorhiza and produces pyomelanin. Considering the various technological uses of pyomelanin, this study underscores the need to explore fungi of different habitats to identify hyperproducers and to obtain chemically diverse pyomelanin.
Collapse
Affiliation(s)
- T S Suryanarayanan
- Vivekananda Institute of Tropical Mycology, Ramakrishna Mission Vidyapith, Chennai, India.
| | - M B Govindarajulu
- Vivekananda Institute of Tropical Mycology, Ramakrishna Mission Vidyapith, Chennai, India
| | - T S Murali
- Department of Public Health Genomics, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal, India
| | - J P Ravishankar
- Vivekananda Institute of Tropical Mycology, Ramakrishna Mission Vidyapith, Chennai, India
| | - S Bharathwaj
- Vivekananda Institute of Tropical Mycology, Ramakrishna Mission Vidyapith, Chennai, India
| | - M D Kalaiarasan
- Vivekananda Institute of Tropical Mycology, Ramakrishna Mission Vidyapith, Chennai, India
| |
Collapse
|
4
|
Kumari D, Sachivkina N, Pasrija R. Investigation of the influence of pH and temperature on melanization and survival under oxidative stress in Cryptococcus neoformans. Arch Microbiol 2024; 206:355. [PMID: 39017938 DOI: 10.1007/s00203-024-04080-7] [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: 04/16/2024] [Revised: 07/04/2024] [Accepted: 07/08/2024] [Indexed: 07/18/2024]
Abstract
Cryptococcus neoformans is an opportunistic pathogenic fungus that produces melanin during infection, an important virulence factor in Cryptococcal infections that enhances the ability of the fungus to resist immune defense. This fungus can synthesize melanin from a variety of substrates, including L-DOPA (L-3,4-dihydroxyphenylalanine). Since melanin protects the fungus from various stress factors such as oxidative, nitrosative, extreme heat and cold stress; we investigated the effects of environmental conditions on melanin production and survival. In this study, we investigated the effects of different pH values (5.6, 7.0 and 8.5) and temperatures (30 °C and 37 °C) on melanization and cell survival using a microtiter plate-based melanin production assay and an oxidative stress assay, respectively. In addition, the efficacy of compounds known to inhibit laccase involved in melanin synthesis, i.e., tunicamycin, β-mercaptoethanol, dithiothreitol, sodium azide and caspofungin on melanization was evaluated and their sensitivity to temperature and pH changes was measured. The results showed that melanin content correlated with pH and temperature changes and that pH 8.5 and 30 °C, were best for melanin production. Besides that, melanin production protects the fungal cells from oxidative stress induced by hydrogen peroxide. Thus, changes in pH and temperature drastically alter melanin production in C. neoformans and it correlates with the fungal survival. Due to the limited antifungal repertoire and the development of resistance in cryptococcal infections, the investigation of environmental conditions in the regulation of melanization and survival of C. neoformans could be useful for future research and clinical phasing.
Collapse
Affiliation(s)
- Deepika Kumari
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, 124001, India
| | - Nadezhda Sachivkina
- Department of Microbiology, Peoples' Friendship University of Russia, Moscow, 117198, Russia
| | - Ritu Pasrija
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, 124001, India.
| |
Collapse
|
5
|
Rudhra O, Gnanam H, Sivaperumal S, Namperumalsamy V, Prajna L, Kuppamuthu D. Melanin depletion affects Aspergillus flavus conidial surface proteins, architecture, and virulence. Appl Microbiol Biotechnol 2024; 108:291. [PMID: 38592509 PMCID: PMC11004046 DOI: 10.1007/s00253-024-13107-4] [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: 08/17/2023] [Revised: 03/06/2024] [Accepted: 03/10/2024] [Indexed: 04/10/2024]
Abstract
Melanin is an Aspergillus flavus cell wall component that provides chemical and physical protection to the organism. However, the molecular and biological mechanisms modulating melanin-mediated host-pathogen interaction in A. flavus keratitis are not well understood. This work aimed to compare the morphology, surface proteome profile, and virulence of melanized conidia (MC) and non-melanized conidia (NMC) of A. flavus. Kojic acid treatment inhibited melanin synthesis in A. flavus, and the conidial surface protein profile was significantly different in kojic acid-treated non-melanized conidia. Several cell wall-associated proteins and proteins responsible for oxidative stress, carbohydrate, and chitin metabolic pathways were found only in the formic acid extracts of NMC. Scanning electron microscopy (SEM) analysis showed the conidial surface morphology difference between the NMC and MC, indicating the role of melanin in the structural integrity of the conidial cell wall. The levels of calcofluor white staining efficiency were different, but there was no microscopic morphology difference in lactophenol cotton blue staining between MC and NMC. Evaluation of the virulence of MC and NMC in the Galleria mellonella model showed NMC was less virulent compared to MC. Our findings showed that the integrity of the conidial surface is controlled by the melanin layer. The alteration in the surface protein profile indicated that many surface proteins are masked by the melanin layer, and hence, melanin can modulate the host response by preventing the exposure of fungal proteins to the host immune defense system. The G. mellonella virulence assay also confirmed that the NMC were susceptible to host defense as in other Aspergillus pathogens. KEY POINTS: • l-DOPA melanin production was inhibited in A. flavus isolates by kojic acid, and for the first time, scanning electron microscopy (SEM) analysis revealed morphological differences between MC and NMC of A. flavus strains • Proteome profile of non-melanized conidia showed more conidial surface proteins and these proteins were mainly involved in the virulence, oxidative stress, and metabolism pathways • Non-melanized conidia of A. flavus strains were shown to be less virulent than melanised conidia in an in vivo virulence experiment with the G. melonella model.
Collapse
Affiliation(s)
- Ondippili Rudhra
- Department of Proteomics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Hariharan Gnanam
- Department of Proteomics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Sivaramakrishnan Sivaperumal
- Department of Biotechnology and Genetic Engineering, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | | | - Lalitha Prajna
- Department of Ocular Microbiology, Aravind Eye Hospital, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | | |
Collapse
|
6
|
Shankar J, Thakur R, Clemons KV, Stevens DA. Interplay of Cytokines and Chemokines in Aspergillosis. J Fungi (Basel) 2024; 10:251. [PMID: 38667922 PMCID: PMC11051073 DOI: 10.3390/jof10040251] [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: 02/06/2024] [Revised: 03/11/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Aspergillosis is a fungal infection caused by various species of Aspergillus, most notably A. fumigatus. This fungus causes a spectrum of diseases, including allergic bronchopulmonary aspergillosis, aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis. The clinical manifestations and severity of aspergillosis can vary depending on individual immune status and the specific species of Aspergillus involved. The recognition of Aspergillus involves pathogen-associated molecular patterns (PAMPs) such as glucan, galactomannan, mannose, and conidial surface proteins. These are recognized by the pathogen recognition receptors present on immune cells such as Toll-like receptors (TLR-1,2,3,4, etc.) and C-type lectins (Dectin-1 and Dectin-2). We discuss the roles of cytokines and pathogen recognition in aspergillosis from both the perspective of human and experimental infection. Several cytokines and chemokines have been implicated in the immune response to Aspergillus infection, including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), CCR4, CCR17, and other interleukins. For example, allergic bronchopulmonary aspergillosis (ABPA) is characterized by Th2 and Th9 cell-type immunity and involves interleukin (IL)-4, IL-5, IL-13, and IL-10. In contrast, it has been observed that invasive aspergillosis involves Th1 and Th17 cell-type immunity via IFN-γ, IL-1, IL-6, and IL-17. These cytokines activate various immune cells and stimulate the production of other immune molecules, such as antimicrobial peptides and reactive oxygen species, which aid in the clearance of the fungal pathogen. Moreover, they help to initiate and coordinate the immune response, recruit immune cells to the site of infection, and promote clearance of the fungus. Insight into the host response from both human and animal studies may aid in understanding the immune response in aspergillosis, possibly leading to harnessing the power of cytokines or cytokine (receptor) antagonists and transforming them into precise immunotherapeutic strategies. This could advance personalized medicine.
Collapse
Affiliation(s)
- Jata Shankar
- Genomic Laboratory, Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat Solan 173234, Himachal Pradesh, India
| | - Raman Thakur
- Department of Medical Laboratory Science, Lovely Professional University, Jalandhar 144001, Punjab, India;
| | - Karl V. Clemons
- California Institute for Medical Research, San Jose, CA 95128, USA; (K.V.C.); (D.A.S.)
- Division of Infectious Diseases and Geographic Medicine, Stanford University Medical School, Stanford, CA 94305, USA
| | - David A. Stevens
- California Institute for Medical Research, San Jose, CA 95128, USA; (K.V.C.); (D.A.S.)
- Division of Infectious Diseases and Geographic Medicine, Stanford University Medical School, Stanford, CA 94305, USA
| |
Collapse
|
7
|
Guruceaga X, Perez-Cuesta U, Martin-Vicente A, Pelegri-Martinez E, Thorn HI, Cendon-Sanchez S, Xie J, Nywening AV, Ramirez-Garcia A, Fortwendel JR, Rementeria A. The Aspergillus fumigatus maiA gene contributes to cell wall homeostasis and fungal virulence. Front Cell Infect Microbiol 2024; 14:1327299. [PMID: 38343890 PMCID: PMC10853476 DOI: 10.3389/fcimb.2024.1327299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/08/2024] [Indexed: 02/15/2024] Open
Abstract
In this study, two distinct in vitro infection models of Aspergillus fumigatus, using murine macrophages (RAW264.7) and human lung epithelial cells (A549), were employed to identify the genes important for fungal adaptation during infection. Transcriptomic analyses of co-incubated A. fumigatus uncovered 140 fungal genes up-regulated in common between both models that, when compared with a previously published in vivo transcriptomic study, allowed the identification of 13 genes consistently up-regulated in all three infection conditions. Among them, the maiA gene, responsible for a critical step in the L-phenylalanine degradation pathway, was identified. Disruption of maiA resulted in a mutant strain unable to complete the Phe degradation pathway, leading to an excessive production of pyomelanin when this amino acid served as the sole carbon source. Moreover, the disruption mutant exhibited noticeable cell wall abnormalities, with reduced levels of β-glucans within the cell wall but did not show lack of chitin or mannans. The maiA-1 mutant strain induced reduced inflammation in primary macrophages and displayed significantly lower virulence in a neutropenic mouse model of infection. This is the first study linking the A. fumigatus maiA gene to fungal cell wall homeostasis and virulence.
Collapse
Affiliation(s)
- Xabier Guruceaga
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Uxue Perez-Cuesta
- Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Eduardo Pelegri-Martinez
- Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Harrison I. Thorn
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
- Graduate Program in Pharmaceutical Science, College of Graduate Health Sciences, University of Tennessee Healths Science Center, Memphis, TN, United States
| | - Saioa Cendon-Sanchez
- Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Jinhong Xie
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
- Graduate Program in Pharmaceutical Science, College of Graduate Health Sciences, University of Tennessee Healths Science Center, Memphis, TN, United States
| | - Ashley V. Nywening
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Andoni Ramirez-Garcia
- Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Aitor Rementeria
- Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain
| |
Collapse
|
8
|
Stuckey PV, Santiago-Tirado FH. Fungal mechanisms of intracellular survival: what can we learn from bacterial pathogens? Infect Immun 2023; 91:e0043422. [PMID: 37506189 PMCID: PMC10501222 DOI: 10.1128/iai.00434-22] [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: 11/28/2022] [Accepted: 06/23/2023] [Indexed: 07/30/2023] Open
Abstract
Fungal infections represent a major, albeit neglected, public health threat with serious medical and economic burdens globally. With unacceptably high mortality rates, invasive fungal pathogens are responsible for millions of deaths each year, with a steadily increasing incidence primarily in immunocompromised individuals. The poor therapeutic options and rise of antifungal drug resistance pose further challenges in controlling these infections. These fungal pathogens have adapted to survive within mammalian hosts and can establish intracellular niches to promote survival within host immune cells. To do that, they have developed diverse methods to circumvent the innate immune system attack. This includes strategies such as altering their morphology, counteracting macrophage antimicrobial action, and metabolic adaptation. This is reminiscent of how bacterial pathogens have adapted to survive within host cells and cause disease. However, relative to the great deal of information available concerning intracellular bacterial pathogenesis, less is known about the mechanisms fungal pathogens employ. Therefore, here we review our current knowledge and recent advances in our understanding of how fungi can evade and persist within host immune cells. This review will focus on the major fungal pathogens, including Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus, among others. As we discover and understand the strategies used by these fungi, similarities with their bacterial counterparts are becoming apparent, hence we can use the abundant information from bacteria to guide our studies in fungi. By understanding these strategies, new lines of research will open that can improve the treatments of these devastating fungal diseases.
Collapse
Affiliation(s)
- Peter V. Stuckey
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Felipe H. Santiago-Tirado
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
- Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana, USA
| |
Collapse
|
9
|
Koch SM, Freidank-Pohl C, Siontas O, Cortesao M, Mota A, Runzheimer K, Jung S, Rebrosova K, Siler M, Moeller R, Meyer V. Aspergillus niger as a cell factory for the production of pyomelanin, a molecule with UV-C radiation shielding activity. Front Microbiol 2023; 14:1233740. [PMID: 37547691 PMCID: PMC10399693 DOI: 10.3389/fmicb.2023.1233740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/03/2023] [Indexed: 08/08/2023] Open
Abstract
Melanins are complex pigments with various biological functions and potential applications in space exploration and biomedicine due to their radioprotective properties. Aspergillus niger, a fungus known for its high radiation resistance, is widely used in biotechnology and a candidate for melanin production. In this study, we investigated the production of fungal pyomelanin (PyoFun) in A. niger by inducing overproduction of the pigment using L-tyrosine in a recombinant ΔhmgA mutant strain (OS4.3). The PyoFun pigment was characterized using three spectroscopic methods, and its antioxidant properties were assessed using a DPPH-assay. Additionally, we evaluated the protective effect of PyoFun against non-ionizing radiation (monochromatic UV-C) and compared its efficacy to a synthetically produced control pyomelanin (PyoSyn). The results confirmed successful production of PyoFun in A. niger through inducible overproduction. Characterization using spectroscopic methods confirmed the presence of PyoFun, and the DPPH-assay demonstrated its strong antioxidant properties. Moreover, PyoFun exhibited a highly protective effect against radiation-induced stress, surpassing the protection provided by PyoSyn. The findings of this study suggest that PyoFun has significant potential as a biological shield against harmful radiation. Notably, PyoFun is synthesized extracellularly, differing it from other fungal melanins (such as L-DOPA- or DHN-melanin) that require cell lysis for pigment purification. This characteristic makes PyoFun a valuable resource for biotechnology, biomedicine, and the space industry. However, further research is needed to evaluate its protective effect in a dried form and against ionizing radiation.
Collapse
Affiliation(s)
- Stella Marie Koch
- Radiation Biology Department, Aerospace Microbiology Research Group, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
| | - Carsten Freidank-Pohl
- Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Oliver Siontas
- Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Marta Cortesao
- Radiation Biology Department, Aerospace Microbiology Research Group, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
| | - Afonso Mota
- Radiation Biology Department, Aerospace Microbiology Research Group, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
| | - Katharina Runzheimer
- Radiation Biology Department, Aerospace Microbiology Research Group, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
| | - Sascha Jung
- Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Katarina Rebrosova
- Department of Microbiology, Faculty of Medicine, Masaryk University (MUNI) and St. Anne's Faculty Hospital, Brno, Czechia
| | - Martin Siler
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czechia
| | - Ralf Moeller
- Radiation Biology Department, Aerospace Microbiology Research Group, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
| | - Vera Meyer
- Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| |
Collapse
|
10
|
Jones AM, Panaccione DG. Ergot Alkaloids Contribute to the Pathogenic Potential of the Fungus Aspergillus leporis. Appl Environ Microbiol 2023; 89:e0041523. [PMID: 37212708 PMCID: PMC10304750 DOI: 10.1128/aem.00415-23] [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: 03/10/2023] [Accepted: 05/06/2023] [Indexed: 05/23/2023] Open
Abstract
Opportunistically pathogenic fungi have varying potential to cause disease in animals. Factors contributing to their virulence include specialized metabolites, which in some cases evolved in contexts unrelated to pathogenesis. Specialized metabolites that increase fungal virulence in the model insect Galleria mellonella include the ergot alkaloids fumigaclavine C in Aspergillus fumigatus (syn. Neosartorya fumigata) and lysergic acid α-hydroxyethylamide (LAH) in the entomopathogen Metarhizium brunneum. Three species of Aspergillus recently found to accumulate high concentrations of LAH were investigated for their pathogenic potential in G. mellonella. Aspergillus leporis was most virulent, A. hancockii was intermediate, and A. homomorphus had very little pathogenic potential. Aspergillus leporis and A. hancockii emerged from and sporulated on dead insects, thus completing their asexual life cycles. Inoculation by injection resulted in more lethal infections than did topical inoculation, indicating that A. leporis and A. hancockii were preadapted for insect pathogenesis but lacked an effective means to breach the insect's cuticle. All three species accumulated LAH in infected insects, with A. leporis accumulating the most. Concentrations of LAH in A. leporis were similar to those observed in the entomopathogen M. brunneum. LAH was eliminated from A. leporis through a CRISPR/Cas9-based gene knockout, and the resulting strain had reduced virulence to G. mellonella. The data indicate that A. leporis and A. hancockii have considerable pathogenic potential and that LAH increases the virulence of A. leporis. IMPORTANCE Certain environmental fungi infect animals occasionally or conditionally, whereas others do not. Factors that affect the virulence of these opportunistically pathogenic fungi may have originally evolved to fill some other role for the fungus in its primary environmental niche. Among the factors that may improve the virulence of opportunistic fungi are specialized metabolites--chemicals that are not essential for basic life functions but provide producers with an advantage in particular environments or under specific conditions. Ergot alkaloids are a large family of fungal specialized metabolites that contaminate crops in agriculture and serve as the foundations of numerous pharmaceuticals. Our results show that two ergot alkaloid-producing fungi that were not previously known to be opportunistic pathogens can infect a model insect and that, in at least one of the species, an ergot alkaloid increases the virulence of the fungus.
Collapse
Affiliation(s)
- Abigail M. Jones
- West Virginia University, Division of Plant and Soil Sciences, Morgantown, West Virginia, USA
| | - Daniel G. Panaccione
- West Virginia University, Division of Plant and Soil Sciences, Morgantown, West Virginia, USA
| |
Collapse
|
11
|
Li R, Zheng P, Sun X, Dong W, Shen Z, Chen P, Wu D. Genome Sequencing and Analysis Reveal Potential High-Valued Metabolites Synthesized by Lasiodiplodia iranensis DWH-2. J Fungi (Basel) 2023; 9:jof9050522. [PMID: 37233233 DOI: 10.3390/jof9050522] [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: 03/15/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023] Open
Abstract
Lasiodiplodia sp. is a typical opportunistic plant pathogen, which can also be classified as an endophytic fungus. In this study, the genome of a jasmonic-acid-producing Lasiodiplodia iranensis DWH-2 was sequenced and analyzed to understand its application value. The results showed that the L. iranensis DWH-2 genome was 43.01 Mb in size with a GC content of 54.82%. A total of 11,224 coding genes were predicted, among which 4776 genes were annotated based on Gene Ontology. Furthermore, the core genes involved in the pathogenicity of the genus Lasiodiplodia were determined for the first time based on pathogen-host interactions. Eight Carbohydrate-Active enzymes (CAZymes) genes related to 1,3-β-glucan synthesis were annotated based on the CAZy database and three relatively complete known biosynthetic gene clusters were identified based on the Antibiotics and Secondary Metabolites Analysis Shell database, which were associated with the synthesis of 1,3,6,8-tetrahydroxynaphthalene, dimethylcoprogen, and (R)-melanin. Moreover, eight genes associated with jasmonic acid synthesis were detected in pathways related to lipid metabolism. These findings fill the gap in the genomic data of high jasmonate-producing strains.
Collapse
Affiliation(s)
- Ruiying Li
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| | - Pu Zheng
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| | - Xingyun Sun
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| | - Wenhua Dong
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| | - Ziqiang Shen
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| | - Pengcheng Chen
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| | - Dan Wu
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China
| |
Collapse
|
12
|
Lange T, Kasper L, Gresnigt MS, Brunke S, Hube B. "Under Pressure" - How fungi evade, exploit, and modulate cells of the innate immune system. Semin Immunol 2023; 66:101738. [PMID: 36878023 PMCID: PMC10109127 DOI: 10.1016/j.smim.2023.101738] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Indexed: 03/06/2023]
Abstract
The human immune system uses an arsenal of effector mechanisms to prevent and counteract infections. Yet, some fungal species are extremely successful as human pathogens, which can be attributed to a wide variety of strategies by which these fungi evade, exploit, and modulate the immune system. These fungal pathogens normally are either harmless commensals or environmental fungi. In this review we discuss how commensalism, but also life in an environmental niche without human contact, can drive the evolution of diverse and specialized immune evasion mechanisms. Correspondingly, we discuss the mechanisms contributing to the ability of these fungi to cause superficial to life-threatening infections.
Collapse
Affiliation(s)
- Theresa Lange
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Mark S Gresnigt
- Junior Research Group Adaptive Pathogenicity Strategies, Hans Knoell Institute, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany; Institute of Microbiology, Friedrich Schiller University, Jena, Germany.
| |
Collapse
|
13
|
The Lipid Raft-Associated Protein Stomatin Is Required for Accumulation of Dectin-1 in the Phagosomal Membrane and for Full Activity of Macrophages against Aspergillus fumigatus. mSphere 2023; 8:e0052322. [PMID: 36719247 PMCID: PMC9942578 DOI: 10.1128/msphere.00523-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Alveolar macrophages belong to the first line of defense against inhaled conidia of the human-pathogenic fungus Aspergillus fumigatus. In lung alveoli, they contribute to phagocytosis and elimination of conidia. As a counterdefense, conidia have a gray-green pigment that enables them to survive in phagosomes of macrophages for some time. Previously, we showed that this conidial pigment interferes with the formation of flotillin-dependent lipid raft microdomains in the phagosomal membrane, thereby preventing the formation of functional phagolysosomes. Besides flotillins, stomatin is a major component of lipid rafts and can be targeted to the membrane. However, only limited information on stomatin is available, in particular on its role in defense against pathogens. To determine the function of this integral membrane protein, a stomatin-deficient macrophage line was generated by CRISPR/Cas9 gene editing. Immunofluorescence microscopy and flow cytometry revealed that stomatin contributes to the phagocytosis of conidia and is important for recruitment of the β-glucan receptor dectin-1 to both the cytoplasmic membrane and phagosomal membrane. In stomatin knockout cells, fusion of phagosomes and lysosomes, recruitment of the vATPase to phagosomes, and tumor necrosis factor alpha (TNF-α) levels were reduced when cells were infected with pigmentless conidia. Thus, our data suggest that stomatin is involved in maturation of phagosomes via fostering fusion of phagosomes with lysosomes. IMPORTANCE Stomatin is an integral membrane protein that contributes to the uptake of microbes, e.g., spores of the human-pathogenic fungus Aspergillus fumigatus. By generation of a stomatin-deficient macrophage line by advanced genetic engineering, we found that stomatin is involved in the recruitment of the β-glucan receptor dectin-1 to the phagosomal membrane of macrophages. Furthermore, stomatin is involved in maturation of phagosomes via fostering fusion of phagosomes with lysosomes. The data provide new insights on the important role of stomatin in the immune response against human-pathogenic fungi.
Collapse
|
14
|
Solid-state NMR molecular snapshots of Aspergillus fumigatus cell wall architecture during a conidial morphotype transition. Proc Natl Acad Sci U S A 2023; 120:e2212003120. [PMID: 36719915 PMCID: PMC9963690 DOI: 10.1073/pnas.2212003120] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
While establishing an invasive infection, the dormant conidia of Aspergillus fumigatus transit through swollen and germinating stages, to form hyphae. During this morphotype transition, the conidial cell wall undergoes dynamic remodeling, which poses challenges to the host immune system and antifungal drugs. However, such cell wall reorganization during conidial germination has not been studied so far. Here, we explored the molecular rearrangement of Aspergillus fumigatus cell wall polysaccharides during different stages of germination. We took advantage of magic-angle spinning NMR to investigate the cell wall polysaccharides, without employing any destructive method for sample preparation. The breaking of dormancy was associated with a significant change in the molar ratio between the major polysaccharides β-1,3-glucan and α-1,3-glucan, while chitin remained equally abundant. The use of various polarization transfers allowed the detection of rigid and mobile polysaccharides; the appearance of mobile galactosaminogalactan was a molecular hallmark of germinating conidia. We also report for the first time highly abundant triglyceride lipids in the mobile matrix of conidial cell walls. Water to polysaccharides polarization transfers revealed an increased surface exposure of glucans during germination, while chitin remained embedded deeper in the cell wall, suggesting a molecular compensation mechanism to keep the cell wall rigidity. We complement the NMR analysis with confocal and atomic force microscopies to explore the role of melanin and RodA hydrophobin on the dormant conidial surface. Exemplified here using Aspergillus fumigatus as a model, our approach provides a powerful tool to decipher the molecular remodeling of fungal cell walls during their morphotype switching.
Collapse
|
15
|
Chen D, Shu D, Wei Z, Luo D, Yang J, Li Z, Tan H. Combined transcriptome and proteome analysis of Bcfrp1 involved in regulating the biosynthesis of abscisic acid and growth in Botrytis cinerea TB-31. Front Microbiol 2023; 13:1085000. [PMID: 36777027 PMCID: PMC9909433 DOI: 10.3389/fmicb.2022.1085000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/23/2022] [Indexed: 01/27/2023] Open
Abstract
Introduction Abscisic acid (ABA) is an important sesquiterpene compound that regulates the stress resistance of plants. Botrytis cinerea can synthesize ABA via the mevalonic acid pathway. To identify the functional genes that are involved in the biosynthesis of ABA, we performed insertion mutagenesis into B. cinerea TB-31. Methods We obtained the ABA-reduced mutant E154 by insertion mutagenesis, and we identified the insertion site was located upstream of the gene bcfrp1 by Thermal asymmetric interlaced PCR. We performed a detailed phenotypic characterization of the bcfrp1 knockout and complementation mutants in TB-31. Furthermore, transcriptome and proteome analyses were conducted to explore how bcfrp1 affects the level of the ABA biosynthesis. Results The bcfrp1 gene encodes an F-box protein. The phenotypic results confirmed the positive contribution of bcfrp1 to the biosynthesis of ABA and growth. Between TB-31 and ΔBcfrp1, we obtained 4,128 and 1,073 differentially expressed genes and proteins, respectively. The impaired ABA biosynthesis in the ΔBcfrp1 mutants was primarily affected by the different levels of expression of the ABA biosynthetic gene cluster and the genes involved in the mevalonic acid pathway. In addition, we further characterized the differentially expressed genes and proteins that participated in the growth, secondary metabolism, and signal transduction in B. cinerea based on the transcriptome and proteome data. Discussion This research based on the transcriptome and proteome analyses to display the changes after the deletion of bcfrp1 in B. cinerea TB-31, will help us to explore the molecular mechanism of ABA biosynthesis in B. cinerea.
Collapse
Affiliation(s)
- Dongbo Chen
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China,Chengdu Institute of Biology, China Academy of Sciences (CAS), University of the Chinese Academy of Sciences, Chengdu, China
| | - Dan Shu
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China,*Correspondence: Dan Shu, ✉
| | - Zhao Wei
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China,Chengdu Institute of Biology, China Academy of Sciences (CAS), University of the Chinese Academy of Sciences, Chengdu, China
| | - Di Luo
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Jie Yang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Zhemin Li
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Hong Tan
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China,Hong Tan, ✉
| |
Collapse
|
16
|
Li K, Wei Z, Jia J, Xu Q, Liu H, Zhong C, Huang H. Engineered living materials grown from programmable Aspergillus niger mycelial pellets. Mater Today Bio 2023; 19:100545. [PMID: 36793323 PMCID: PMC9922812 DOI: 10.1016/j.mtbio.2023.100545] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/15/2023] Open
Abstract
The development of engineered living materials (ELMs) has recently attracted significant attention from researchers across multiple disciplines. Fungi-derived ELMs represent a new type of macroscale, cost-effective, environmentally sustainable materials. However, current fungi-based ELMs either have to undergo a final process to heat-kill the living cells or rely on the co-culture with a model organism for functional modification, which hinders the engineerability and versatility of these materials. In this study, we report a new type of ELMs - grown from programmable Aspergillus niger mycelial pellets - by a simple filtration step under ambient conditions. We demonstrate that A. Niger pellets can provide sufficient cohesion to maintain large-area self-supporting structures even under low pH conditions. Subsequently, by tuning the inducible expression of genes involved in melanin biosynthesis, we verified the fabrication of self-supporting living membrane materials with tunable colors in response to xylose concentration in the surroundings, which can be further explored as a potential biosensor for detecting xylose level in industrial wastewater. Notably, the living materials remain alive, self-regenerative, and functional even after 3-month storage. Thus, beyond reporting a new engineerable fungi chassis for constructing ELMs, our study provides new opportunities for developing bulk living materials for real-world applications such as the production of fabrics, packaging materials, and biosensors.
Collapse
Affiliation(s)
- Ke Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 211816, China
| | - Zhen Wei
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Jianyao Jia
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 211816, China
| | - Qing Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 211816, China
| | - Hao Liu
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, Tianjin, 300457, China,Corresponding author. MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China.
| | - Chao Zhong
- Center for Materials Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China,Corresponding author. Center for Materials Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 211816, China,Corresponding author.
| |
Collapse
|
17
|
Is the production of reactive oxygen and nitrogen species by macrophages associated with better infectious control in female mice with experimentally disseminated and pulmonary mucormycosis? PLoS One 2022; 17:e0270071. [PMID: 36520787 PMCID: PMC9754262 DOI: 10.1371/journal.pone.0270071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 11/08/2022] [Indexed: 12/23/2022] Open
Abstract
Different levels of resistance against Rhizopus oryzae infection have been observed between inbred (BALB/c) and outbred (Swiss) mice and are associated with the genetic background of each mouse strain. Considering that macrophages play an important role in host resistance to Rhizopus species, we used different infectious outcomes observed in experimental mucormycosis to identify the most efficient macrophage response pattern against R. oryzae in vitro and in vivo. For this, we compared BALB/c and Swiss macrophage activity before and after intravenous or intratracheal R. oryzae infections. The production of hydrogen peroxide (H2O2) and nitric oxide (NO) was determined in cultures of peritoneal (PMΦ) or alveolar macrophages (AMΦ) challenged with heat-killed spores of R. oryzae. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) were measured to confirm our findings. Naïve PMΦ from female BALB/c mice showed increased production of H2O2, TNF-α, and IL-10 in the presence of heat-killed spores of R. oryzae. Naïve PMΦ from female Swiss mice were less responsive. Naïve AMΦ from the two strains of female mice were less reactive to heat-killed spores of R. oryzae than PMΦ. After 30 days of R. oryzae intravenous infection, lower fungal load in spleen from BALB/c mice was accompanied by higher production of H2O2 by PMΦ compared with Swiss mice. In contrast, AMΦ from BALB/c mice showed higher production of NO, TNF-α, and IL-10 after 7 days of intratracheal infection. The collective findings reveal that, independent of the female mouse strain, PMΦ is more reactive against R. oryzae upon first contact than AMΦ. In addition, increased PMΦ production of H2O2 at the end of disseminated infection is accompanied by better fungal clearance in resistant (BALB/c) mice. Our findings further the understanding of the parasite-host relationship in mucormycosis.
Collapse
|
18
|
Orekhova A, De Angelis M, Cacciotti A, Reverberi M, Rotili D, Giorgi A, Protto V, Bonincontro G, Fiorentino F, Zgoda V, Mai A, Palamara AT, Simonetti G. Modulation of Virulence-Associated Traits in Aspergillus fumigatus by BET Inhibitor JQ1. Microorganisms 2022; 10:2292. [PMID: 36422362 PMCID: PMC9698166 DOI: 10.3390/microorganisms10112292] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/13/2022] [Accepted: 11/15/2022] [Indexed: 08/18/2024] Open
Abstract
Aspergillus fumigatus is a disease-causing, opportunistic fungus that can establish infection due to its capacity to respond to a wide range of environmental conditions. Secreted proteins and metabolites, which play a critical role in fungal-host interactions and pathogenesis, are modulated by epigenetic players, such as bromodomain and extraterminal domain (BET) proteins. In this study, we evaluated the in vitro and in vivo capability of the BET inhibitor JQ1 to modulate the extracellular proteins and virulence of A. fumigatus. The abundance of 25 of the 76 extracellular proteins identified through LC-MS/MS proteomic analysis changed following JQ1 treatment. Among them, a ribonuclease, a chitinase, and a superoxide dismutase were dramatically downregulated. Moreover, the proteomic analysis of A. fumigatus intracellular proteins indicated that Abr2, an intracellular laccase involved in the last step of melanin synthesis, was absent in the JQ1-treated group. To investigate at which level this downregulation occurred and considering the ability of JQ1 to modulate gene expression we checked the level of ABR2, Chitinase, and Superoxide dismutase mRNA expression by qRT-PCR. Finally, the capacity of JQ1 to reduce the virulence of A. fumigatus has been proved using Galleria mellonella larvae, which are an in vivo model to evaluate fungal virulence. Overall, the promising activity exhibited by JQ1 suggests that A. fumigatus is sensitive to BET inhibition and BET proteins may be a viable target for developing antifungal agents.
Collapse
Affiliation(s)
- Anastasia Orekhova
- Department of Public Health and Infectious Diseases, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Marta De Angelis
- Department of Public Health and Infectious Diseases, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Andrea Cacciotti
- Department of Environmental Biology, “Sapienza” University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Massimo Reverberi
- Department of Environmental Biology, “Sapienza” University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Dante Rotili
- Department of Drug Chemistry and Technologies, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Alessandra Giorgi
- Department of Biochemical Sciences, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Virginia Protto
- Department of Public Health and Infectious Diseases, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Graziana Bonincontro
- Department of Environmental Biology, “Sapienza” University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Francesco Fiorentino
- Department of Drug Chemistry and Technologies, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Victor Zgoda
- Institute of Biomedical Chemistry, Moscow, 10 Pogodinskaya Street, Moscow 119121, Russia
| | - Antonello Mai
- Department of Drug Chemistry and Technologies, “Sapienza” University of Rome, 00185 Rome, Italy
| | - Anna Teresa Palamara
- Department of Public Health and Infectious Diseases, “Sapienza” University of Rome, 00185 Rome, Italy
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Giovanna Simonetti
- Department of Environmental Biology, “Sapienza” University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| |
Collapse
|
19
|
Response and regulatory mechanisms of heat resistance in pathogenic fungi. Appl Microbiol Biotechnol 2022; 106:5415-5431. [PMID: 35941254 PMCID: PMC9360699 DOI: 10.1007/s00253-022-12119-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 12/03/2022]
Abstract
Abstract Both the increasing environmental temperature in nature and the defensive body temperature response to pathogenic fungi during mammalian infection cause heat stress during the fungal existence, reproduction, and pathogenic infection. To adapt and respond to the changing environment, fungi initiate a series of actions through a perfect thermal response system, conservative signaling pathways, corresponding transcriptional regulatory system, corresponding physiological and biochemical processes, and phenotypic changes. However, until now, accurate response and regulatory mechanisms have remained a challenge. Additionally, at present, the latest research progress on the heat resistance mechanism of pathogenic fungi has not been summarized. In this review, recent research investigating temperature sensing, transcriptional regulation, and physiological, biochemical, and morphological responses of fungi in response to heat stress is discussed. Moreover, the specificity thermal adaptation mechanism of pathogenic fungi in vivo is highlighted. These data will provide valuable knowledge to further understand the fungal heat adaptation and response mechanism, especially in pathogenic heat-resistant fungi. Key points • Mechanisms of fungal perception of heat pressure are reviewed. • The regulatory mechanism of fungal resistance to heat stress is discussed. • The thermal adaptation mechanism of pathogenic fungi in the human body is highlighted.
Collapse
|
20
|
Verburg K, van Neer J, Duca M, de Cock H. Novel Treatment Approach for Aspergilloses by Targeting Germination. J Fungi (Basel) 2022; 8:758. [PMID: 35893126 PMCID: PMC9331470 DOI: 10.3390/jof8080758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/03/2022] [Accepted: 07/19/2022] [Indexed: 12/24/2022] Open
Abstract
Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.
Collapse
Affiliation(s)
- Kim Verburg
- Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (K.V.); (J.v.N.)
| | - Jacq van Neer
- Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (K.V.); (J.v.N.)
| | - Margherita Duca
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands;
| | - Hans de Cock
- Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (K.V.); (J.v.N.)
| |
Collapse
|
21
|
Gibbons JG, D’Avino P, Zhao S, Cox GW, Rinker DC, Fortwendel JR, Latge JP. Comparative Genomics Reveals a Single Nucleotide Deletion in pksP That Results in White-Spore Phenotype in Natural Variants of Aspergillus fumigatus. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:897954. [PMID: 37746219 PMCID: PMC10512363 DOI: 10.3389/ffunb.2022.897954] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/03/2022] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is a potentially deadly opportunistic human pathogen. A. fumigatus has evolved a variety of mechanisms to evade detection by the immune system. For example, the conidium surface is covered in a layer of 1,8-dihydroxynaphthalene (DHN) melanin which masks the antigen macrophages use for recognition. DHN melanin also protects conidia from ultraviolet radiation and gives A. fumigatus conidia their characteristic green-grayish color. Here, we conducted genomic analysis of two closely related white-spore natural variants of A. fumigatus in comparison to two closely related green-spore isolates to identify a genetic basis of the white-spore phenotype. Illumina whole-genome resequencing data of the four isolates was used to identify variants that were shared in the white-spore isolates and different from both the green-spore isolates and the Af293 reference genome (which is also a green-spore isolate). We identified 4,279 single nucleotide variants and 1,785 insertion/deletions fitting this pattern. Among these, we identified 64 variants predicted to be high impact, loss-of-function mutations. One of these variants is a single nucleotide deletion that results in a frameshift in pksP (Afu2g17600), the core biosynthetic gene in the DHN melanin encoding gene cluster. The frameshift mutation in the white-spore isolates leads to a truncated protein in which a phosphopantetheine attachment site (PP-binding domain) is interrupted and an additional PP-binding domain and a thioesterase domain are omitted. Growth rate analysis of white-spore and green-spore isolates at 37°C and 48°C revealed that white-spore isolates are thermosensitive. Growth rate of A. fumigatus Af293 and a pksP null mutant in the Af293 background suggests pksP is not directly involved in the thermosensitivity phenotype. Further, our study identified a mutation in a gene (Afu4g04740) associated with thermal sensitivity in yeasts which could also be responsible for the thermosensitivity of the white-spore mutants. Overall, we used comparative genomics to identify the mutation and protein alterations responsible for the white-spore phenotype of environmental isolates of A. fumigatus.
Collapse
Affiliation(s)
- John G. Gibbons
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
- Organismic & Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
| | - Paolo D’Avino
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
| | - Shu Zhao
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
| | - Grace W. Cox
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - David C. Rinker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, United States
| | | |
Collapse
|
22
|
Li H, Wang D, Zhang DD, Geng Q, Li JJ, Sheng RC, Xue HS, Zhu H, Kong ZQ, Dai XF, Klosterman SJ, Subbarao KV, Chen FM, Chen JY. A polyketide synthase from Verticillium dahliae modulates melanin biosynthesis and hyphal growth to promote virulence. BMC Biol 2022; 20:125. [PMID: 35637443 PMCID: PMC9153097 DOI: 10.1186/s12915-022-01330-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/13/2022] [Indexed: 01/15/2023] Open
Abstract
Background During the disease cycle, plant pathogenic fungi exhibit a morphological transition between hyphal growth (the phase of active infection) and the production of long-term survival structures that remain dormant during “overwintering.” Verticillium dahliae is a major plant pathogen that produces heavily melanized microsclerotia (MS) that survive in the soil for 14 or more years. These MS are multicellular structures produced during the necrotrophic phase of the disease cycle. Polyketide synthases (PKSs) are responsible for catalyzing production of many secondary metabolites including melanin. While MS contribute to long-term survival, hyphal growth is key for infection and virulence, but the signaling mechanisms by which the pathogen maintains hyphal growth are unclear. Results We analyzed the VdPKSs that contain at least one conserved domain potentially involved in secondary metabolism (SM), and screened the effect of VdPKS deletions in the virulent strain AT13. Among the five VdPKSs whose deletion affected virulence on cotton, we found that VdPKS9 acted epistatically to the VdPKS1-associated melanin pathway to promote hyphal growth. The decreased hyphal growth in VdPKS9 mutants was accompanied by the up-regulation of melanin biosynthesis and MS formation. Overexpression of VdPKS9 transformed melanized hyphal-type (MH-type) into the albinistic hyaline hyphal-type (AH-type), and VdPKS9 was upregulated in the AH-type population, which also exhibited higher virulence than the MH-type. Conclusions We show that VdPKS9 is a powerful negative regulator of both melanin biosynthesis and MS formation in V. dahliae. These findings provide insight into the mechanism of how plant pathogens promote their virulence by the maintenance of vegetative hyphal growth during infection and colonization of plant hosts, and may provide novel targets for the control of melanin-producing filamentous fungi. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01330-2.
Collapse
|
23
|
Ren D, Wang T, Zhou G, Ren W, Duan X, Gao L, Chen J, Xu L, Zhu P. Ethylene Promotes Expression of the Appressorium- and Pathogenicity-Related Genes via GPCR- and MAPK-Dependent Manners in Colletotrichum gloeosporioides. J Fungi (Basel) 2022; 8:jof8060570. [PMID: 35736053 PMCID: PMC9224669 DOI: 10.3390/jof8060570] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/20/2022] [Accepted: 05/25/2022] [Indexed: 01/27/2023] Open
Abstract
Ethylene (ET) represents a signal that can be sensed by plant pathogenic fungi to accelerate their spore germination and subsequent infection. However, the molecular mechanisms of responses to ET in fungi remain largely unclear. In this study, Colletotrichum gloeosporioides was investigated via transcriptomic analysis to reveal the genes that account for the ET-regulated fungal development and virulence. The results showed that ET promoted genes encoding for fungal melanin biosynthesis enzymes, extracellular hydrolases, and appressorium-associated structure proteins at 4 h after treatment. When the germination lasted until 24 h, ET induced multiple appressoria from every single spore, but downregulated most of the genes. Loss of selected ET responsive genes encoding for scytalone dehydratase (CgSCD1) and cerato-platanin virulence protein (CgCP1) were unable to alter ET sensitivity of C. gloeosporioides in vitro but attenuated the influence of ET on pathogenicity. Knockout of the G-protein-coupled receptors CgGPCR3-1/2 and the MAPK signaling pathway components CgMK1 and CgSte11 resulted in reduced ET sensitivity. Taken together, this study in C. gloeosporioides reports that ET can cause transcription changes in a large set of genes, which are mainly responsible for appressorium development and virulence expression, and these processes are dependent on the GPCR and MAPK pathways.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Ling Xu
- Correspondence: (L.X.); (P.Z.); Tel.: +86-(021)-54341012 (L.X.); +86-(021)-24206574 (P.Z.)
| | - Pinkuan Zhu
- Correspondence: (L.X.); (P.Z.); Tel.: +86-(021)-54341012 (L.X.); +86-(021)-24206574 (P.Z.)
| |
Collapse
|
24
|
Lorquin F, Piccerelle P, Orneto C, Robin M, Lorquin J. New insights and advances on pyomelanin production: from microbial synthesis to applications. J Ind Microbiol Biotechnol 2022; 49:6575554. [PMID: 35482661 PMCID: PMC9338888 DOI: 10.1093/jimb/kuac013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/21/2022] [Indexed: 11/14/2022]
Abstract
Pyomelanin is a brown-black phenolic polymer and results from the oxidation of homogentisic acid (HGA) in the L-tyrosine pathway. As part of the research for natural and active ingredients issued from realistic bioprocesses, this work re-evaluates the HGA pigment and makes an updated inventory of its syntheses, microbial pathways, and properties, with tracks and recent advances for its large-scale production. The mechanism of the HGA polymerization is also well documented. In alkaptonuria, pyomelanin formation leads to connective tissue damages and arthritis, most probably due to the ROS issued from HGA oxidation. While UV radiation on human melanin may generate degradation products, pyomelanin is not photodegradable, is hyperthermostable, and has other properties better than the L-Dopa melanin. This review aims to raise awareness about the potential of this pigment for various applications, not only for skin coloring and protection but also for other cells, materials, and as a promising (semi)conductor for bioelectronics and energy.
Collapse
Affiliation(s)
- Faustine Lorquin
- Aix-Marseille Université, Mediterranean Institute of Oceanology (MIO), 163 avenue de Luminy, 13288 Marseille Cedex 9, France.,Aix-Marseille Université, Mediterranean Institute of Marine and Terrestrial Biodiversity and Ecology (IMBE), 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Philippe Piccerelle
- Aix-Marseille Université, Mediterranean Institute of Marine and Terrestrial Biodiversity and Ecology (IMBE), 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Caroline Orneto
- Aix-Marseille Université, Mediterranean Institute of Marine and Terrestrial Biodiversity and Ecology (IMBE), 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Maxime Robin
- Aix-Marseille Université, Mediterranean Institute of Marine and Terrestrial Biodiversity and Ecology (IMBE), 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Jean Lorquin
- Aix-Marseille Université, Mediterranean Institute of Oceanology (MIO), 163 avenue de Luminy, 13288 Marseille Cedex 9, France
| |
Collapse
|
25
|
El-Kamand S, Steiner M, Ramirez C, Halliday C, Chen SCA, Papanicolaou A, Morton CO. Assessing Differences between Clinical Isolates of Aspergillus fumigatus from Cases of Proven Invasive Aspergillosis and Colonizing Isolates with Respect to Phenotype (Virulence in Tenebrio molitor Larvae) and Genotype. Pathogens 2022; 11:pathogens11040428. [PMID: 35456102 PMCID: PMC9029132 DOI: 10.3390/pathogens11040428] [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: 03/03/2022] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 02/01/2023] Open
Abstract
The fungus Aspergillus fumigatus, the cause of invasive aspergillosis (IA), is a serious risk to transplant patients and those with respiratory diseases. Host immune suppression is considered the most important factor for the development of IA. Less is known about the importance of fungal virulence in the development of IA including the significance of variation between isolates. In this study, isolates of A. fumigatus from cases diagnosed as having proven IA or colonisation (no evidence of IA) were compared in assays to measure isolate virulence. These assays included the measurement of radial growth and protease production on agar, sensitivity to UV light and oxidative stressors, and virulence in Tenebrio molitor (mealworm) larvae. These assays did not reveal obvious differences in virulence between the two groups of isolates; this provided the impetus to conduct genomic analysis. Whole genome sequencing and analysis did not allow grouping into coloniser or IA isolates. However, focused analysis of single nucleotide polymorphisms revealed variation in three putative genes: AFUA_5G09420 (ccg-8), AFUA_4G00330, and AFUA_4G00350. These are known to be responsive to azole exposure, and ccg-8 deletion leads to azole hypersensitivity in other fungi. A. fumigatus virulence is challenging, but the findings of this study indicate that further research into the response to oxidative stress and azole exposure are required to understand the development of IA.
Collapse
Affiliation(s)
- Sam El-Kamand
- Western Sydney University, School of Science, Campbelltown Campus, Campbelltown, NSW 2560, Australia; (S.E.-K.); (M.S.); (C.R.)
| | - Martina Steiner
- Western Sydney University, School of Science, Campbelltown Campus, Campbelltown, NSW 2560, Australia; (S.E.-K.); (M.S.); (C.R.)
| | - Carl Ramirez
- Western Sydney University, School of Science, Campbelltown Campus, Campbelltown, NSW 2560, Australia; (S.E.-K.); (M.S.); (C.R.)
| | - Catriona Halliday
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead Hospital, Westmead, NSW 2145, Australia; (C.H.); (S.C.-A.C.)
| | - Sharon C.-A. Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead Hospital, Westmead, NSW 2145, Australia; (C.H.); (S.C.-A.C.)
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW 2145, Australia
| | - Alexie Papanicolaou
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, NSW 2753, Australia
- Correspondence: (A.P.); (C.O.M.); Tel.: +61-2-4570-1385 (A.P.); +61-2-4620-3446 (C.O.M.)
| | - Charles Oliver Morton
- Western Sydney University, School of Science, Campbelltown Campus, Campbelltown, NSW 2560, Australia; (S.E.-K.); (M.S.); (C.R.)
- Correspondence: (A.P.); (C.O.M.); Tel.: +61-2-4570-1385 (A.P.); +61-2-4620-3446 (C.O.M.)
| |
Collapse
|
26
|
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.
Collapse
|
27
|
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.
Collapse
|
28
|
Lim W, Konings M, Parel F, Eadie K, Strepis N, Fahal A, Verbon A, van de Sande WWJ. OUP accepted manuscript. Med Mycol 2022; 60:6513817. [PMID: 35064672 PMCID: PMC9295015 DOI: 10.1093/mmy/myac003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/19/2021] [Accepted: 01/08/2022] [Indexed: 11/13/2022] Open
Abstract
Eumycetoma is a neglected tropical disease, and Madurella mycetomatis, the most common causative agent of this disease forms black grains in hosts. Melanin was discovered to be one of the constituents in grains. Melanins are hydrophobic, macromolecular pigments formed by oxidative polymerisation of phenolic or indolic compounds. M. mycetomatis was previously known to produce DHN-melanin and pyomelanin in vitro. These melanin was also discovered to decrease M. mycetomatis’s susceptibility to antifungals itraconazole and ketoconazole in vitro. These findings, however, have not been confirmed in vivo. To discover the melanin biosynthesis pathways used by M. mycetomatis in vivo and to determine if inhibiting melanin production would increase M. mycetomatis's susceptibility to itraconazole, inhibitors targeting DHN-, DOPA- and pyomelanin were used. Treatment with DHN-melanin inhibitors tricyclazole, carpropamid, fenoxanil and DOPA-melanin inhibitor glyphosate in M. mycetomatis infected Galleria mellonella larvae resulted in presence of non-melanized grains. Our finding suggested that M. mycetomatis is able to produce DOPA-melanin in vivo. Inhibiting DHN-melanin with carpropamid in combination with the antifungal itraconazole also significantly increased larvae survival. Our results suggested that combination treatment of antifungals and melanin inhibitors can be an alternative treatment strategy that can be further explored. Since the common black-grain eumycetoma causing agents uses similar melanin biosynthesis pathways, this strategy may be applied to them and other eumycetoma causative agents.
Collapse
Affiliation(s)
- Wilson Lim
- Erasmus MC, University Medical Center Rotterdam, Department of Medical Microbiology and Infectious Diseases, Rotterdam, the Netherlands
| | - Mickey Konings
- Erasmus MC, University Medical Center Rotterdam, Department of Medical Microbiology and Infectious Diseases, Rotterdam, the Netherlands
| | - Florianne Parel
- Erasmus MC, University Medical Center Rotterdam, Department of Medical Microbiology and Infectious Diseases, Rotterdam, the Netherlands
| | - Kimberly Eadie
- Erasmus MC, University Medical Center Rotterdam, Department of Medical Microbiology and Infectious Diseases, Rotterdam, the Netherlands
| | - Nikolaos Strepis
- Erasmus MC, University Medical Center Rotterdam, Department of Medical Microbiology and Infectious Diseases, Rotterdam, the Netherlands
| | - Ahmed Fahal
- Mycetoma Research Centre, University of Khartoum, Khartoum, Sudan
| | - Annelies Verbon
- Erasmus MC, University Medical Center Rotterdam, Department of Medical Microbiology and Infectious Diseases, Rotterdam, the Netherlands
| | - Wendy W J van de Sande
- To whom correspondence should be addressed. Wendy van de Sande, Assoc Prof. Erasmus MC, University Medical Center Rotterdam, Department of Microbiology and Infectious Diseases, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. Tel: +31 10 703 35 10; E-mail:
| |
Collapse
|
29
|
Anusha P, Narayanan M, Natarajan D, Kandasamy S, Chinnathambi A, Alharbi SA, Brindhadevi K. Assessment of hexavalent chromium (VI) biosorption competence of indigenous Aspergillus tubingensis AF3 isolated from bauxite mine tailing. CHEMOSPHERE 2021; 282:131055. [PMID: 34118617 DOI: 10.1016/j.chemosphere.2021.131055] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 05/20/2021] [Accepted: 05/29/2021] [Indexed: 06/12/2023]
Abstract
The intention of this research was to find the most eminent metal tolerant and absorbing autochthonous fungal species from the waste dump of a bauxite mine. Out of the 4 (BI-1, BI-II, BI-III, and BI-IV) predominant isolates, BI-II had an excellent metal tolerance potential against most of the metals in the subsequent order: Cr(VI) (1500), Cu(II) (600), Pb(II) (500), and Zn(II) (500-1500 μg mL-1). BI-II had shown tolerance to Cr(VI) up to 1500 mg L-1. The excellent metal tolerant isolate was characterized and identified as Aspergillus tubingensis AF3 through 18S rRNA sequencing method and submitted to GenBank and received an accession number (MN901243). A. tubingensis AF3 had the efficiency to absorb Cr(VI) and Cu(II) at <70 & 46.3% respectively under the standard growth conditions. Under the optimized conditions (25 °C, pH 7.0, 0.5% of dextrose, and 12 days of incubation), A. tubingensis AF3 absorbed 74.48% of Cr(VI) in 12 days (reduction occurred as 822.3, 719.13, 296.66, and 255.2 mg L-1 of Cr(VI) on the 3rd, the 6th, the 9th and the 12th day, respectively). The adsorbed metal was sequestered in the mycelia of the fungus in a precipitated form; it was confirmed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray analysis (EDX) analyses. The possible biosorption mechanisms were analyzed by Fourier-Transform Infrared Spectroscopy (FTIR) analysis, the results showed the presence of N-H primary amines (1649.98 cm-1) and Alkanes (914.30 cm-1) in the cell wall of the fungus, while being treated with Cr(VI) they supported and enhanced the Cr(VI) absorption. The entire results concluded that the biomass of A. tubingensis AF3 had the potential to absorb a high concentration of Cr(VI).
Collapse
Affiliation(s)
- Ponniah Anusha
- Natural Drug Research Laboratory, Department of Biotechnology, Periyar University, Salem, Tamil Nadu, India
| | - Mathiyazhagan Narayanan
- PG and Research Centre in Biotechnology, MGR College, Adhiyamaan Educational Research Institute, Hosur, Tamil Nadu, India
| | - Devarajan Natarajan
- Natural Drug Research Laboratory, Department of Biotechnology, Periyar University, Salem, Tamil Nadu, India.
| | | | - Arunachalam Chinnathambi
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box -2455, Riyadh, 11451, Saudi Arabia
| | - Sulaiman Ali Alharbi
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box -2455, Riyadh, 11451, Saudi Arabia
| | - Kathirvel Brindhadevi
- Faculty of Electrical and Electronics Engineering, Ton Duc Thang, University, Ho Chi Minh City, Viet Nam.
| |
Collapse
|
30
|
Fernandes C, Mota M, Barros L, Dias MI, Ferreira ICFR, Piedade AP, Casadevall A, Gonçalves T. Pyomelanin Synthesis in Alternaria alternata Inhibits DHN-Melanin Synthesis and Decreases Cell Wall Chitin Content and Thickness. Front Microbiol 2021; 12:691433. [PMID: 34512569 PMCID: PMC8430343 DOI: 10.3389/fmicb.2021.691433] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/26/2021] [Indexed: 12/15/2022] Open
Abstract
The genus Alternaria includes several of fungi that are darkly pigmented by DHN-melanin. These are pathogenic to plants but are also associated with human respiratory allergic diseases and with serious infections in immunocompromised individuals. The present work focuses on the alterations of the composition and structure of the hyphal cell wall of Alternaria alternata occuring under the catabolism of L-tyrosine and L-phenylalanine when cultured in minimal salt medium (MM). Under these growing conditions, we observed the released of a brown pigment into the culture medium. FTIR analysis demonstrates that the produced pigment is chemically identical to the pigment released when the fungus is grown in MM with homogentisate acid (HGA), the intermediate of pyomelanin, confirming that this pigment is pyomelanin. In contrast to other fungi that also synthesize pyomelanin under tyrosine metabolism, A. alternata inhibits DHN-melanin cell wall accumulation when pyomelanin is produced, and this is associated with reduced chitin cell wall content. When A. alternata is grown in MM containing L-phenylalanine, a L-tyrosine percursor, pyomelanin is synthesized but only at trace concentrations and A. alternata mycelia display an albino-like phenotype since DHN-melanin accumulation is inhibited. CmrA, the transcription regulator for the genes coding for the DHN-melanin pathway, is involved in the down-regulation of DHN-melanin synthesis when pyomelanin is being synthetized, since the CMRA gene and genes of the enzymes involved in DHN-melanin synthesis pathway showed a decreased expression. Other amino acids do not trigger pyomelanin synthesis and DHN-melanin accumulation in the cell wall is not affected. Transmission and scanning electron microscopy show that the cell wall structure and surface decorations are altered in L-tyrosine- and L-phenylalanine-grown fungi, depending on the pigment produced. In summary, growth in presence of L-tyrosine and L-phenylalanine leads to pigmentation and cell wall changes, which could be relevant to infection conditions where these amino acids are expected to be available.
Collapse
Affiliation(s)
- Chantal Fernandes
- CNC—Center for Neuroscience and Cell Biology of Coimbra, Coimbra, Portugal
| | - Marta Mota
- CNC—Center for Neuroscience and Cell Biology of Coimbra, Coimbra, Portugal
- FMUC—Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Lillian Barros
- Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Bragança, Portugal
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Bragança, Portugal
| | - Maria Inês Dias
- Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Bragança, Portugal
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Bragança, Portugal
| | - Isabel C. F. R. Ferreira
- Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Bragança, Portugal
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Bragança, Portugal
| | - Ana P. Piedade
- Centre for Mechanical Engineering, Materials and Processes, Department of Mechanical Engineering, University of Coimbra, Coimbra, Portugal
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Teresa Gonçalves
- CNC—Center for Neuroscience and Cell Biology of Coimbra, Coimbra, Portugal
- FMUC—Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| |
Collapse
|
31
|
Boysen JM, Saeed N, Hillmann F. Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus. Beilstein J Org Chem 2021; 17:1814-1827. [PMID: 34394757 PMCID: PMC8336654 DOI: 10.3762/bjoc.17.124] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/14/2021] [Indexed: 11/30/2022] Open
Abstract
The kingdom of fungi comprises a large and highly diverse group of organisms that thrive in diverse natural environments. One factor to successfully confront challenges in their natural habitats is the capability to synthesize defensive secondary metabolites. The genetic potential for the production of secondary metabolites in fungi is high and numerous potential secondary metabolite gene clusters have been identified in sequenced fungal genomes. Their production may well be regulated by specific ecological conditions, such as the presence of microbial competitors, symbionts or predators. Here we exemplarily summarize our current knowledge on identified secondary metabolites of the pathogenic fungus Aspergillus fumigatus and their defensive function against (microbial) predators.
Collapse
Affiliation(s)
- Jana M Boysen
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Nauman Saeed
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Falk Hillmann
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| |
Collapse
|
32
|
Abstract
Infections due to Aspergillus species are an acute threat to human health; members of the Aspergillus section Fumigati are the most frequently occurring agents, but depending on the local epidemiology, representatives of section Terrei or section Flavi are the second or third most important. Aspergillus terreus species complex is of great interest, as it is usually amphotericin B resistant and displays notable differences in immune interactions in comparison to Aspergillus fumigatus. The latest epidemiological surveys show an increased incidence of A. terreus as well as an expanding clinical spectrum (chronic infections) and new groups of at-risk patients being affected. Hallmarks of these non-Aspergillus fumigatus invasive mold infections are high potential for tissue invasion, dissemination, and possible morbidity due to mycotoxin production. We seek to review the microbiology, epidemiology, and pathogenesis of A. terreus species complex, address clinical characteristics, and highlight the underlying mechanisms of amphotericin B resistance. Selected topics will contrast key elements of A. terreus with A. fumigatus. We provide a comprehensive resource for clinicians dealing with fungal infections and researchers working on A. terreus pathogenesis, aiming to bridge the emerging translational knowledge and future therapeutic challenges on this opportunistic pathogen.
Collapse
|
33
|
Freeing Aspergillus fumigatus of Polymycovirus Infection Renders It More Resistant to Competition with Pseudomonas aeruginosa Due to Altered Iron-Acquiring Tactics. J Fungi (Basel) 2021; 7:jof7070497. [PMID: 34206595 PMCID: PMC8306778 DOI: 10.3390/jof7070497] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/15/2021] [Accepted: 06/18/2021] [Indexed: 12/31/2022] Open
Abstract
A virus-free (VF) A. fumigatus isolate has been shown to be resistant in competition with Pseudomonas as compared to the isogenic line infected with Aspergillus fumigatus polymycovirus 1 (AfuPmV-1), and this phenotype was apparently related to alterations in iron metabolism. Here we investigated further the mechanisms underpinning this phenotype. The extracellular siderophore profiles of five isogenic VF and virus-infected (VI) strains were sampled at 24, 31, 48, 54, and 72 h in submerged cultures and quantitatively examined by liquid chromatography and mass spectrometry. Intracellular profiles of conidia and cultures at the stationary growth phase were defined. VF A. fumigatus demonstrated the best fitness represented by the fastest onset of its exponential growth when grown on an iron-limited mineral medium. The exponential phase and transitional production phase of the extracellular triacetylfusarinine C (TafC) were achieved at 24 and 31 h, respectively, contrary to VI strains, which acted more slowly. As a result, the TafC reservoir was consumed sooner in the VF strain. Additionally, the VF strain had lower ferricrocin and higher hydroxyferricrocin content in the pellet during the stationary phase. All of these differences were significant (Kruskal–Wallis, p < 0.01). In our study, the siderophore reservoir of a VF strain was consumed sooner, improving the fitness of the VF strain in competition with P. aeruginosa.
Collapse
|
34
|
Fungal Melanins and Applications in Healthcare, Bioremediation and Industry. J Fungi (Basel) 2021; 7:jof7060488. [PMID: 34207260 PMCID: PMC8235761 DOI: 10.3390/jof7060488] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/13/2021] [Accepted: 06/13/2021] [Indexed: 01/01/2023] Open
Abstract
Melanin is a complex multifunctional pigment found in all kingdoms of life, including fungi. The complex chemical structure of fungal melanins, yet to be fully elucidated, lends them multiple unique functions ranging from radioprotection and antioxidant activity to heavy metal chelation and organic compound absorption. Given their many biological functions, fungal melanins present many possibilities as natural compounds that could be exploited for human use. This review summarizes the current discourse and attempts to apply fungal melanin to enhance human health, remove pollutants from ecosystems, and streamline industrial processes. While the potential applications of fungal melanins are often discussed in the scientific community, they are successfully executed less often. Some of the challenges in the applications of fungal melanin to technology include the knowledge gap about their detailed structure, difficulties in isolating melanotic fungi, challenges in extracting melanin from isolated species, and the pathogenicity concerns that accompany working with live melanotic fungi. With proper acknowledgment of these challenges, fungal melanin holds great potential for societal benefit in the coming years.
Collapse
|
35
|
Characterisation of Aspergillus fumigatus Endocytic Trafficking within Airway Epithelial Cells Using High-Resolution Automated Quantitative Confocal Microscopy. J Fungi (Basel) 2021; 7:jof7060454. [PMID: 34200399 PMCID: PMC8229978 DOI: 10.3390/jof7060454] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 12/15/2022] Open
Abstract
The precise characterization of the mechanisms modulating Aspergillus fumigatus survival within airway epithelial cells has been impaired by the lack of live-cell imaging technologies and user-friendly quantification approaches. Here we described the use of an automated image analysis pipeline to estimate the proportion of A. fumigatus spores taken up by airway epithelial cells, those contained within phagolysosomes or acidified phagosomes, along with the fungal factors contributing to these processes. Coupling the use of fluorescent A. fumigatus strains and fluorescent epithelial probes targeting lysosomes, acidified compartments and cell membrane, we found that both the efficacy of lysosome recruitment to phagosomes and phagosome acidification determines the capacity of airway epithelial cells to contain A. fumigatus growth. Overall, the capability of the airway epithelium to prevent A. fumigatus survival was higher in bronchial epithelial than alveolar epithelial cells. Certain A. fumigatus cell wall mutants influenced phagosome maturation in airway epithelial cells. Taken together, this live-cell 4D imaging approach allows observation and measurement of the very early processes of A. fumigatus interaction within live airway epithelial monolayers.
Collapse
|
36
|
Johns LE, Goldman GH, Ries LN, Brown NA. Nutrient sensing and acquisition in fungi: mechanisms promoting pathogenesis in plant and human hosts. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
37
|
Flotillin-Dependent Membrane Microdomains Are Required for Functional Phagolysosomes against Fungal Infections. Cell Rep 2021; 32:108017. [PMID: 32814035 PMCID: PMC10054021 DOI: 10.1016/j.celrep.2020.108017] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/03/2020] [Accepted: 07/17/2020] [Indexed: 11/23/2022] Open
Abstract
Lipid rafts form signaling platforms on biological membranes with incompletely characterized role in immune response to infection. Here we report that lipid-raft microdomains are essential components of phagolysosomal membranes of macrophages and depend on flotillins. Genetic deletion of flotillins demonstrates that the assembly of both major defense complexes vATPase and NADPH oxidase requires membrane microdomains. Furthermore, we describe a virulence mechanism leading to dysregulation of membrane microdomains by melanized wild-type conidia of the important human-pathogenic fungus Aspergillus fumigatus resulting in reduced phagolysosomal acidification. We show that phagolysosomes with ingested melanized conidia contain a reduced amount of free Ca2+ ions and that inhibition of Ca2+-dependent calmodulin activity led to reduced lipid-raft formation. We identify a single-nucleotide polymorphism in the human FLOT1 gene resulting in heightened susceptibility for invasive aspergillosis in hematopoietic stem cell transplant recipients. Collectively, flotillin-dependent microdomains on the phagolysosomal membrane play an essential role in protective antifungal immunity.
Collapse
|
38
|
Understanding the fundamental role of virulence determinants to combat Aspergillus fumigatus infections: exploring beyond cell wall. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01677-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
39
|
Compartmentalization of Melanin Biosynthetic Enzymes Contributes to Self-Defense against Intermediate Compound Scytalone in Botrytis cinerea. mBio 2021; 12:mBio.00007-21. [PMID: 33758088 PMCID: PMC8092192 DOI: 10.1128/mbio.00007-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
In filamentous fungi, 1,8-dihydroxynaphthalene (DHN) melanin is a major component of the extracellular matrix, endowing fungi with environmental tolerance and some pathogenic species with pathogenicity. However, the subcellular location of the melanin biosynthesis pathway components remains obscure. Using the gray mold pathogen Botrytis cinerea, the DHN melanin intermediate scytalone was characterized via phenotypic and chemical analysis of mutants, and the key enzymes participating in melanin synthesis were fused with fluorescent proteins to observe their subcellular localizations. The Δbcscd1 mutant accumulated scytalone in the culture filtrate rather than in mycelium. Excessive scytalone appears to be self-inhibitory to the fungus, leading to repressed sclerotial germination and sporulation in the Δbcscd1 mutant. The BcBRN1/2 enzymes responsible for synthesizing scytalone were localized in endosomes and found to be trafficked to the cell surface, accompanied by the accumulation of BcSCD1 proteins in the cell wall. In contrast, the early-stage melanin synthesis enzymes BcPKS12/13 and BcYGH1 were localized in peroxisomes. Taken together, the results of this study revealed the subcellular distribution of melanin biosynthetic enzymes in B. cinerea, indicating that the encapsulation and externalization of the melanin synthetic enzymes need to be delicately orchestrated to ensure enzymatic efficiency and protect itself from the adverse effect of the toxic intermediate metabolite.IMPORTANCE The devastating gray mold pathogen Botrytis cinerea propagates via melanized conidia and sclerotia. This study reveals that the sclerotial germination of B. cinerea is differentially affected by different enzymes in the melanin synthesis pathway. Using gene knockout mutants and chemical analysis, we found that excessive accumulation of the melanin intermediate scytalone is inhibitory to B. cinerea. Subcellular localization analysis of the melanin synthesis enzymes of B. cinerea suggested two-stage partitioning of the melanogenesis pathway: the intracellular stage involves the steps until the intermediate scytalone was translocated to the cell surface, whereas the extracellular stage comprises all the steps occurring in the wall from scytalone to final melanin formation. These strategies make the fungus avert self-poisoning during melanin production. This study opens avenues for better understanding the mechanisms of secondary metabolite production in filamentous fungi.
Collapse
|
40
|
Williams TJ, Gonzales-Huerta LE, Armstrong-James D. Fungal-Induced Programmed Cell Death. J Fungi (Basel) 2021; 7:jof7030231. [PMID: 33804601 PMCID: PMC8003624 DOI: 10.3390/jof7030231] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 01/01/2023] Open
Abstract
Fungal infections are a cause of morbidity in humans, and despite the availability of a range of antifungal treatments, the mortality rate remains unacceptably high. Although our knowledge of the interactions between pathogenic fungi and the host continues to grow, further research is still required to fully understand the mechanism underpinning fungal pathogenicity, which may provide new insights for the treatment of fungal disease. There is great interest regarding how microbes induce programmed cell death and what this means in terms of the immune response and resolution of infection as well as microbe-specific mechanisms that influence cell death pathways to aid in their survival and continued infection. Here, we discuss how programmed cell death is induced by fungi that commonly cause opportunistic infections, including Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans, the role of programmed cell death in fungal immunity, and how fungi manipulate these pathways.
Collapse
|
41
|
Mandal V, Adhikary R, Maiti PK, Mandal S, Mandal V. Morpho-biochemical and molecular characterization of two new strains of Aspergillus fumigatus nHF-01 and A. fumigatus PPR-01 producing broad-spectrum antimicrobial compounds. Braz J Microbiol 2021; 52:905-917. [PMID: 33715141 DOI: 10.1007/s42770-021-00439-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 02/02/2021] [Indexed: 11/30/2022] Open
Abstract
The main objective of the study is to characterize two new strains of Aspergillus fumigatus through morphometric, biochemical, molecular methods, and to evaluate their antimicrobial potentiality. The micro-morphotaxonomy, growth, and metabolic behavior of the strains, nHF-01 and PPR-01, were studied in different growth conditions and compared with standard strain. The molecular characterization was done by sequencing the ncrDNA ITS1-5.8S-ITS2 and D1-D2 domains of the nc 28S rDNA region and compared with a secondary structure-based phylogenetic tree. The secretory antimicrobials and pigments were characterized by TLC, UV-Vis, and FT-IR spectroscopy. Both the strains showed distinct growth patterns in different nutritional media and could assimilate a wide range of carbohydrates with distinctive biochemical properties. The molecular characterization revealed the strains, nHF-01 and PPR-01, as Aspergillus fumigatus (GenBank Accession No. MN190286 and MN190284, respectively). It was observed that the strain nHF-01 produces red to brownish pigments having mild antimicrobial activity while the strain PPR-01 does not represent such transformations. The extractable compounds had a significant antimicrobial potentiality against the human pathogenic bacteria. From this analysis, it can be concluded that the nHF-01 and PPR-01 strains are distinct from other A. fumigatus by their unique characters. Large-scale production and detailed molecular elucidation of the antimicrobial compounds may lead to the discovery of new antimicrobial compounds from these strains.
Collapse
Affiliation(s)
- Vivekananda Mandal
- Plant and Microbial Physiology and Biochemistry Laboratory, Department of Botany, University of Gour Banga, P.O. - Mokdumpur, Malda, WB, 732 103, India
| | - Rajsekhar Adhikary
- Plant and Microbial Physiology and Biochemistry Laboratory, Department of Botany, University of Gour Banga, P.O. - Mokdumpur, Malda, WB, 732 103, India
| | - Pulak Kumar Maiti
- Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700 019, India
| | - Sukhendu Mandal
- Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700 019, India
| | - Vivekananda Mandal
- Plant and Microbial Physiology and Biochemistry Laboratory, Department of Botany, University of Gour Banga, P.O. - Mokdumpur, Malda, WB, 732 103, India.
| |
Collapse
|
42
|
Margalit A, Carolan JC, Kavanagh K. Bacterial Interactions with Aspergillus fumigatus in the Immunocompromised Lung. Microorganisms 2021; 9:microorganisms9020435. [PMID: 33669831 PMCID: PMC7923216 DOI: 10.3390/microorganisms9020435] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022] Open
Abstract
The immunocompromised airways are susceptible to infections caused by a range of pathogens which increases the opportunity for polymicrobial interactions to occur. Pseudomonas aeruginosa and Staphylococcus aureus are the predominant causes of pulmonary infection for individuals with respiratory disorders such as cystic fibrosis (CF). The spore-forming fungus Aspergillus fumigatus, is most frequently isolated with P. aeruginosa, and co-infection results in poor outcomes for patients. It is therefore clinically important to understand how these pathogens interact with each other and how such interactions may contribute to disease progression so that appropriate therapeutic strategies may be developed. Despite its persistence in the airways throughout the life of a patient, A. fumigatus rarely becomes the dominant pathogen. In vitro interaction studies have revealed remarkable insights into the molecular mechanisms that drive agonistic and antagonistic interactions that occur between A. fumigatus and pulmonary bacterial pathogens such as P. aeruginosa. Crucially, these studies demonstrate that although bacteria may predominate in a competitive environment, A. fumigatus has the capacity to persist and contribute to disease.
Collapse
Affiliation(s)
| | | | - Kevin Kavanagh
- Correspondence: ; Tel.: +353-1-708-3859; Fax: +353-1-708-3845
| |
Collapse
|
43
|
Light Signaling Regulates Aspergillus niger Biofilm Formation by Affecting Melanin and Extracellular Polysaccharide Biosynthesis. mBio 2021; 12:mBio.03434-20. [PMID: 33593965 PMCID: PMC8545115 DOI: 10.1128/mbio.03434-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Light is an important signal source in nature, which regulates the physiological cycle, morphogenetic pathways, and secondary metabolites of fungi. As an external pressure on Aspergillus niger, light signaling transmits stress signals into the cell via the mitogen-activated protein kinase (MAPK) signaling pathway. Studying the effect of light on the biofilm of A. niger will provide a theoretical basis for light in the cultivation of filamentous fungi and industrial applications. Here, the characterization of A. niger biofilm under different light intensities confirmed the effects of light signaling. Our results indicated that A. niger intensely accumulated protective mycelial melanin under light illumination. We also discovered that the RlmA transcription factor in the MAPK signaling pathway is activated by light signaling to promote the synthesis of melanin, chitin, and other exopolysaccharides. However, the importance of melanin to A. niger biofilm is rarely reported; therefore, we knocked out key genes of the melanin biosynthetic pathway—Abr1 and Ayg1. Changes in hydrophobicity and electrostatic forces resulted in the decrease of biofilm caused by the decrease of melanin in mutants.
Collapse
|
44
|
Kitisin T, Ampawong S, Muangkaew W, Sukphopetch P. Phenomic profiling of a novel sibling species within the Scedosporium complex in Thailand. BMC Microbiol 2021; 21:42. [PMID: 33563219 PMCID: PMC7874643 DOI: 10.1186/s12866-021-02105-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
Background Scedosporium species are a group of pathogenic fungi, which can be found worldwide around high human-impacted areas. Infections of Scedosporium have been reported in several immunocompromised and immunocompetent patients with a high mortality rate. Recently, we have isolated and identified several Scedosporium strains during an environmental survey in Thailand. Results We describe the isolate, TMMI-012, possibly a new species isolated from soils in the Chatuchak public park, Bangkok, Thailand. TMMI-012 is phylogenetically related to the Scedosporium genus and is a sibling to S. boydii but shows distinct morphological and pathological characteristics. It is fast growing and highly resistant to antifungal drugs and abiotic stresses. Pathological studies of in vitro and in vivo models confirm its high virulence and pathogenicity. Conclusion TMMI-012 is considered a putative novel Scedosporium species. The high antifungal resistance of TMMI-012 compared with its sibling, Scedosporium species is likely related to its clinical impact on human health.
Collapse
Affiliation(s)
- T Kitisin
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - S Ampawong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - W Muangkaew
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - P Sukphopetch
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| |
Collapse
|
45
|
Cao W, Zhou X, McCallum NC, Hu Z, Ni QZ, Kapoor U, Heil CM, Cay KS, Zand T, Mantanona AJ, Jayaraman A, Dhinojwala A, Deheyn DD, Shawkey MD, Burkart MD, Rinehart JD, Gianneschi NC. Unraveling the Structure and Function of Melanin through Synthesis. J Am Chem Soc 2021; 143:2622-2637. [PMID: 33560127 DOI: 10.1021/jacs.0c12322] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Melanin is ubiquitous in living organisms across different biological kingdoms of life, making it an important, natural biomaterial. Its presence in nature from microorganisms to higher animals and plants is attributed to the many functions of melanin, including pigmentation, radical scavenging, radiation protection, and thermal regulation. Generally, melanin is classified into five types-eumelanin, pheomelanin, neuromelanin, allomelanin, and pyomelanin-based on the various chemical precursors used in their biosynthesis. Despite its long history of study, the exact chemical makeup of melanin remains unclear, and it moreover has an inherent diversity and complexity of chemical structure, likely including many functions and properties that remain to be identified. Synthetic mimics have begun to play a broader role in unraveling structure and function relationships of natural melanins. In the past decade, polydopamine, which has served as the conventional form of synthetic eumelanin, has dominated the literature on melanin-based materials, while the synthetic analogues of other melanins have received far less attention. In this perspective, we will discuss the synthesis of melanin materials with a special focus beyond polydopamine. We will emphasize efforts to elucidate biosynthetic pathways and structural characterization approaches that can be harnessed to interrogate specific structure-function relationships, including electron paramagnetic resonance (EPR) and solid-state nuclear magnetic resonance (ssNMR) spectroscopy. We believe that this timely Perspective will introduce this class of biopolymer to the broader chemistry community, where we hope to stimulate new opportunities in novel, melanin-based poly-functional synthetic materials.
Collapse
Affiliation(s)
| | | | | | | | - Qing Zhe Ni
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Utkarsh Kapoor
- Department of Chemical and Biomolecular Engineering, Colburn Laboratory, University of Delaware, Newark, Delaware 19716, United States
| | - Christian M Heil
- Department of Chemical and Biomolecular Engineering, Colburn Laboratory, University of Delaware, Newark, Delaware 19716, United States
| | - Kristine S Cay
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Tara Zand
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Alex J Mantanona
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Arthi Jayaraman
- Department of Chemical and Biomolecular Engineering, Colburn Laboratory, Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Ali Dhinojwala
- Department of Polymer Science, The University of Akron, Akron, Ohio 44325, United States
| | - Dimitri D Deheyn
- Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, California 92093-0202, United States
| | - Matthew D Shawkey
- Evolution and Optics of Nanostructures Group, Department of Biology, The University of Ghent, 9000 Ghent, Belgium
| | - Michael D Burkart
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Jeffrey D Rinehart
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Nathan C Gianneschi
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| |
Collapse
|
46
|
Leanse LG, Dos Anjos C, Wang Y, Murray CK, Hooper DC, Dai T. Effective treatment of cutaneous mold infections by antimicrobial blue light that is potentiated by quinine. J Infect Dis 2021; 224:1069-1076. [PMID: 33528496 DOI: 10.1093/infdis/jiab058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/26/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Cutaneous mold infections commonly result from an array of traumatic injuries that involve direct inoculation of contaminated soil into wounds. Here, we explored the use of antimicrobial blue light (aBL; 405 nm wavelength) and the combination of aBL with quinine hydrochloride (aBL + Q-HCL) for the treatment of cutaneous mold infections. METHODS Efficacy of aBL and aBL + Q-HCL in killing clinically important pathogenic molds (Aspergillus fumigatus, Aspergillus flavus, and Fusarium oxyprorum) was investigated. Ultra-performance liquid chromatography (UPLC) identified and quantified endogenous porphyrins in the mold conidia. Finally, a mouse model of dermabrasion wound infected with a bioluminescent variant of A. fumigatus was developed to investigate the efficacy of aBL in treating cutaneous mold infections. RESULTS We demonstrated that mold conidia are tolerant to aBL, but Q-HCL enhances efficacy. Transmission electron microscopy revealed intracellular damage by aBL. aBL + Q-HCL resulted in intracellular and cell wall damage. Porphyrins were observed in all mold strains, with A. fumigatus having the highest concentration. aBL and aBL + Q-HCL effectively reduced the burden of A. fumigatus within an established dermabrasion infection that limited recurrence post-treatment. CONCLUSIONS aBL and aBL + Q-HCL may offer a novel approach for the treatment of mold infections.
Collapse
Affiliation(s)
- Leon G Leanse
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA.,Vaccine and Immunotherapy Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Carolina Dos Anjos
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA.,Vaccine and Immunotherapy Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA.,Department of Internal Medicine, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil
| | - Ying Wang
- Department of Laser Medicine, The First Medical Center, Chinese PLA General Hospital, Beijing, China
| | | | - David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA.,Vaccine and Immunotherapy Center, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| |
Collapse
|
47
|
Lin L, Xu J. Fungal Pigments and Their Roles Associated with Human Health. J Fungi (Basel) 2020; 6:E280. [PMID: 33198121 PMCID: PMC7711509 DOI: 10.3390/jof6040280] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022] Open
Abstract
Fungi can produce myriad secondary metabolites, including pigments. Some of these pigments play a positive role in human welfare while others are detrimental. This paper reviews the types and biosynthesis of fungal pigments, their relevance to human health, including their interactions with host immunity, and recent progresses in their structure-activity relationships. Fungal pigments are grouped into carotenoids, melanin, polyketides, and azaphilones, etc. These pigments are phylogenetically broadly distributed. While the biosynthetic pathways for some fungal pigments are known, the majority remain to be elucidated. Understanding the genes and metabolic pathways involved in fungal pigment synthesis is essential to genetically manipulate the production of both the types and quantities of specific pigments. A variety of fungal pigments have shown wide-spectrum biological activities, including promising pharmacophores/lead molecules to be developed into health-promoting drugs to treat cancers, cardiovascular disorders, infectious diseases, Alzheimer's diseases, and so on. In addition, the mechanistic elucidation of the interaction of fungal pigments with the host immune system provides valuable clues for fighting fungal infections. The great potential of fungal pigments have opened the avenues for academia and industries ranging from fundamental biology to pharmaceutical development, shedding light on our endeavors for disease prevention and treatment.
Collapse
Affiliation(s)
- Lan Lin
- School of Life Science and Technology, Department of Bioengineering, Key Laboratory of Developmental Genes and Human Diseases (MOE), Southeast University, Nanjing 210096, Jiangsu, China;
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| |
Collapse
|
48
|
Ott LC, Appleton HJ, Shi H, Keener K, Mellata M. High voltage atmospheric cold plasma treatment inactivates Aspergillus flavus spores and deoxynivalenol toxin. Food Microbiol 2020; 95:103669. [PMID: 33397632 DOI: 10.1016/j.fm.2020.103669] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 10/23/2022]
Abstract
Fungal contamination is a concern for the food industry. Fungal spores resist food sterilization treatments and produce mycotoxins that are toxic for animals and humans. Technologies that deactivate spores and toxins without impacting food quality are desirable. This study demonstrates the efficiency of a high voltage atmospheric cold plasma (HVACP) technology using air to generate reactive oxygen (ROS) and nitrogen (RNS) species for the degradation of Aspergillus flavus cultures and the deoxynivalenol (DON) mycotoxin. Optical emission and absorption spectroscopy demonstrate ionization of hydroxyl groups, atomic oxygen and nitrogen, and confirm production of ROS and RNS, e.g. O3, NO2, NO3, N2O4, and N2O5. Fungal cultures show a depletion in pigmentation and an ~50% spore inactivation after 1-min treatments. Treated spores show surface ablation and membrane degradation by scanning electron microscopy. Twenty-minute direct HVACP treatments of 100 μg of DON in one mL aqueous suspensions resulted in a greater than 99% reduction in DON structure and rescued over 80% of Caco-2 cell viability; however, the same treatment on 100 μg of powdered DON toxin only showed a 33% reduction in DON and only rescued 15% of cell viability. In summary, HVACP air treatment can inactivate both fungal spores and toxins in minutes.
Collapse
Affiliation(s)
- Logan C Ott
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA; Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, USA
| | - Holly J Appleton
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA
| | - Hu Shi
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA
| | - Kevin Keener
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA
| | - Melha Mellata
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA; Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, USA.
| |
Collapse
|
49
|
Aspergillus fumigatus G-Protein Coupled Receptors GprM and GprJ Are Important for the Regulation of the Cell Wall Integrity Pathway, Secondary Metabolite Production, and Virulence. mBio 2020; 11:mBio.02458-20. [PMID: 33051372 PMCID: PMC7554674 DOI: 10.1128/mbio.02458-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A. fumigatus is the main etiological agent of invasive pulmonary aspergillosis, a life-threatening fungal disease that occurs in severely immunocompromised humans. Withstanding the host environment is essential for A. fumigatus virulence, and sensing of extracellular cues occurs primarily through G-protein coupled receptors (GPCRs) that activate signal transduction pathways, which, in turn, regulate fungal development, metabolism, virulence, and mycotoxin biosynthesis. The A. fumigatus genome encodes 15 putative classical GPCRs, with only three having been functionally characterized to date. In this work, we show that the two GPCRs GprM and GprJ regulate the phosphorylation of the mitogen-activated protein kinase MpkA and thus control the regulation of the cell wall integrity pathway. GprM and GprJ are also involved in the regulation of the production of the secondary metabolites fumagillin, pyripyropene, fumigaclavine C, fumiquinazoline, melanin, and fumitremorgin, and this regulation partially occurs through the activation of MpkA. Furthermore, GprM and GprJ are important for virulence in the insect model Galleria mellonella. This work therefore functionally characterizes two GPCRs and shows how they regulate several intracellular pathways that have been shown to be crucial for A. fumigatus virulence. G-protein coupled receptors (GPCRs) are extracellular signaling receptors that sense environmental cues. Fungi sense their environment primarily through GPCR-mediated signaling pathways, which, in turn, regulate fungal development, metabolism, virulence, and mycotoxin biosynthesis. Aspergillus fumigatus is an important human pathogen that causes aspergillosis, a heterogeneous group of diseases that present a wide range of clinical manifestations. Here, we investigate in detail the role of the GPCRs GprM and GprJ in growth and gene expression. GprM and GprJ are important for melanin production and the regulation of the cell wall integrity (CWI) pathway. Overexpression of gprM and gprJ causes a 20 and 50% reduction in growth rate compared to the wild-type (WT) strain and increases sensitivity to cell wall-damaging agents. Phosphorylation of the CWI protein kinase MpkA is increased in the ΔgprM and ΔgprJ strains and decreased in the overexpression mutants compared to the WT strain. Furthermore, differences in cell wall polysaccharide concentrations and organization were observed in these strains. Transcriptome sequencing suggests that GprM and GprJ negatively regulate genes encoding secondary metabolites (SMs). Mass spectrometry analysis confirmed that the production of fumagillin, pyripyropene, fumigaclavine C, fumiquinazoline, and fumitremorgin is reduced in the ΔgprM and ΔgprJ strains, at least partially through the activation of MpkA. Overexpression of grpM also resulted in the regulation of many transcription factors, with AsgA predicted to function downstream of GprM and MpkA signaling. Finally, we show that the ΔgprM and ΔgprJ mutants are reduced in virulence in the Galleria mellonella insect model of invasive aspergillosis.
Collapse
|
50
|
Differential Interactions of Serum and Bronchoalveolar Lavage Fluid Complement Proteins with Conidia of Airborne Fungal Pathogen Aspergillus fumigatus. Infect Immun 2020; 88:IAI.00212-20. [PMID: 32571987 DOI: 10.1128/iai.00212-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/15/2020] [Indexed: 12/20/2022] Open
Abstract
Even though both cellular and humoral immunities contribute to host defense, the role played by humoral immunity against the airborne opportunistic fungal pathogen Aspergillus fumigatus has been underexplored. In this study, we aimed at deciphering the role of the complement system, the major humoral immune component, against A. fumigatus Mass spectrometry analysis of the proteins extracted from A. fumigatus conidial (asexual spores and infective propagules) surfaces opsonized with human serum indicated that C3 is the major complement protein involved. Flow cytometry and immunolabeling assays further confirmed C3b (activated C3) deposition on the conidial surfaces. Assays using cell wall components of conidia indicated that the hydrophobin RodAp, β-(1,3)-glucan (BG) and galactomannan (GM) could efficiently activate C3. Using complement component-depleted sera, we showed that while RodAp activates C3 by the alternative pathway, BG and GM partially follow the classical and lectin pathways, respectively. Opsonization facilitated conidial aggregation and phagocytosis, and complement receptor (CR3 and CR4) blockage on phagocytes significantly inhibited phagocytosis, indicating that the complement system exerts a protective role against conidia by opsonizing them and facilitating their phagocytosis mainly through complement receptors. Conidial opsonization with human bronchoalveolar lavage fluid (BALF) confirmed C3 to be the major complement protein interacting with conidia. Nevertheless, complement C2 and mannose-binding lectin (MBL), the classical and lectin pathway components, respectively, were not identified, indicating that BALF activates the alternative pathway on the conidial surface. Moreover, the cytokine profiles were different upon stimulation of phagocytes with serum- and BALF-opsonized conidia, highlighting the importance of studying interaction of conidia with complement proteins in their biological niche.
Collapse
|