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Ahmed M. Abdel-azeem - One of the best experts on this subject based on the ideXlab platform.
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Taxonomy and Biodiversity of the Genus Chaetomium in Different Habitats
Fungal Biology, 2019Co-Authors: Ahmed M. Abdel-azeemAbstract:Since Gustav Kunze described and published genus Chaetomium in Mykologische Hefte (Leipzig) in 1817, the genus attracted an immense interest worldwide. Chaetomium is a diverse genus occurring worldwide; species from this genus are capable of colonizing various biotopes, such as soils, marine, animal dung, hair, textiles, plant tissues, seeds, and other substrates rich in cellulose. Chaetomium species are the largest genus of saprophytic ascomycetes, which belongs to the Chaetomiaceae family. The taxonomy of Chaetomium has been studied by several authors. Since the establishment of the genus, more than 400 species have been described, many of which were synonymized/excluded, and only 273 Chaetomium species were accepted according to Index Fungorum Partnership (IFP 2019). Due to the diversity of species and of inhabiting environments, Chaetomium spp. might conceive diverse biosynthetic gene clusters, which transform into various secondary metabolites (the fungi languages) to adapt to different ecological environments. Until now, more than 200 compounds with a wide range of bioactive effects have been isolated from Chaetomium spp., but compared with its richness of species, more bioactive secondary metabolites might be found in this member of fungi. Therefore, together with its ubiquitous nature, these species have great significant impacts on ecosystems, agriculture, food production, biotechnology, and human and animal health. The goal of this chapter is to represent the biodiversity of genus Chaetomium in a wide range of environmental habitats including deserts, salterns, agricultural, mangrove, living plants and animals, air, decayed wood, stones, and human. It is intended, in this chapter, to report on the accepted Chaetomium species and to propose a provisional key to their identification.
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Recent Advancements on the Role of Biologically Active Secondary Metabolites from Chaetomium
Fungal Biology, 2019Co-Authors: Shimaa Ragab Hamed, Ahmed M. Abdel-azeem, Parsa Mahmood DarAbstract:Chaetomium is one of the largest genera of saprobic ascomycetes with more than 300 species worldwide; the most common species are C. globosum and C. elatum. Many species in this genus are well known to produce a wide range of natural products; most of the products have a wide spectrum of biological activities, whilst some are toxigenic. Currently, there are more than 300 known bioactive metabolites produced by different Chaetomium spp. In this chapter, the most biologically important toxic metabolites of a variety of Chaetomium species are discussed. Secondary metabolites from Chaetomium have potential biotechnological applications with a market value beyond those in human health, medicine, industrial production, food, or agricultural industries.
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Recent Advances on Occurrence of Genus Chaetomium on Dung
Fungal Biology, 2019Co-Authors: Francisco J. Simões Calaça, Solange Xavier-santos, Ahmed M. Abdel-azeemAbstract:The genus Chaetomium is a member of Chaetomiaceae (Sordariomycetes: Sordariales) with saprobic or parasitic species, growing on plant debris, dung, soil, and other substrates. We briefly described advances and status of Chaetomium on dung in recent years, based on both morphological and molecular characters. It is highlighted that the tipping point to increase our understanding on Chaetomium species ecology and biology is to consider potential substrates where it can be found, as dung, once that genus is not highly specialized to a specific substrate. An advanced knowledge on ecology of this dung-inhabiting fungi will facilitate ecological research and efforts to recognize benefits from secondary metabolites of these fungi as a better understanding of its potential as a plant or animal pathogen. Consequently, a better diagnosis of new Chaetomium species on dung, an extreme environment, will help to achieve maximum benefits from these microorganisms in biotechnological applications.
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Chaetomium in Indoor Environment and Medically Important Species of Chaetomium
Fungal Biology, 2019Co-Authors: Eman A. Attia, Ahmed M. Abdel-azeemAbstract:Infections caused by fungi are a significant contributor to morbidity and mortality in humans. These infections range from comparatively innocuous superficial skin diseases caused by dermatophytes to invasive life-threatening infections. Chaetomium species belong to a large genus of saprobic ascomycetes found on dung, straw, paper, bird feathers, seeds, plant debris, and soil. Although Chaetomium species are rarely implicated in human disease, their spectrum of mycoses includes keratitis, onychomycosis, and sinusitis in immunocompetent individuals and empyema, pneumonia, and fatal disseminated cerebral disease in immunocompromised hosts and intravenous drug users. Since many of the diseases caused by Chaetomium are opportunistic in nature, the pathogenesis of fungal infections is complex and our understanding of how these taxa cause disease has lagged behind bacterial and viral pathogens. However, the application of new genomic and other molecular techniques in recent years has revolutionized the field of fungal pathogenesis. This has resulted in a dramatic improvement in our understanding of how fungi cause disease in humans, and this chapter presents a concise overview of Chaetomium taxa including their role in human diseases.
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Developmental Morphology of Chaetomium and Chaetomiopsis
Fungal Biology, 2019Co-Authors: Ahmed M. Abdel-azeemAbstract:Chaetomium is a widespread genus on which much taxonomic work has been done. There have been quite a number of developmental studies in Chaetomium and much has been learned, although comparatively few EM studies have been undertaken and much remains to be learned from the ultrastructural approach. In this chapter, we investigated, mainly with the scanning electron microscope, the ontogeny of C. dinae Moustafa and Abdul-Wahid and compared it with other species of very related Chaetomium taxa. From the developmental point of view, Chaetomiopsis represents an intermediate state between Ch. Globosum type and Ch. Brasiliense type. This observation has also been reported by several authors whom all admitted that mycelial hair production is likely a species character rather than a concrete pattern of ascogonial development.
Sarah A Ahmed - One of the best experts on this subject based on the ideXlab platform.
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Chaetomium like fungi causing opportunistic infections in humans a possible role for extremotolerance
Fungal Diversity, 2016Co-Authors: Deanna A. Sutton, X.w. Wang, Sarah A Ahmed, Z U Khan, Tarek A A Moussa, Hassan S Alzahrani, Omar A Almaghrabi, Suhail AhmadAbstract:Members of the family Chaetomiaceae are ubiquitous ascosporulating fungi commonly, which reside in soil enriched with manure or cellulosic materials. Their role as human pathogens is largely ignored. However, the ability of some species to grow at high temperature enables them to play an important role as opportunistic pathogens. The family contains several genera and species that have never been reported to cause human infection. Hereby, three new species are described; two belong to the genus Subramaniula and one represents a Chaetomium species. Subramaniula asteroides was isolated from various sources including eye and skin infections as well as from the natural environment, and S. obscura was isolated from a toe infection. Chaetomium anamorphosum was isolated from a kidney transplant patient suffering from fungal peritonitis. All species described were previously misidentified as Papulaspora spp. due to the formation of cellular clumps or bulbil-like structures, which are characteristic of Papulaspora. The isolates failed to form sexual fruit bodies and ascospores remained absent, which is an unusual feature for the generally ascosporulating genera Chaetomium and Subramaniula; minute conidia from phialides were sometimes observed.
Suhail Ahmad - One of the best experts on this subject based on the ideXlab platform.
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Chaetomium like fungi causing opportunistic infections in humans a possible role for extremotolerance
Fungal Diversity, 2016Co-Authors: Deanna A. Sutton, X.w. Wang, Sarah A Ahmed, Z U Khan, Tarek A A Moussa, Hassan S Alzahrani, Omar A Almaghrabi, Suhail AhmadAbstract:Members of the family Chaetomiaceae are ubiquitous ascosporulating fungi commonly, which reside in soil enriched with manure or cellulosic materials. Their role as human pathogens is largely ignored. However, the ability of some species to grow at high temperature enables them to play an important role as opportunistic pathogens. The family contains several genera and species that have never been reported to cause human infection. Hereby, three new species are described; two belong to the genus Subramaniula and one represents a Chaetomium species. Subramaniula asteroides was isolated from various sources including eye and skin infections as well as from the natural environment, and S. obscura was isolated from a toe infection. Chaetomium anamorphosum was isolated from a kidney transplant patient suffering from fungal peritonitis. All species described were previously misidentified as Papulaspora spp. due to the formation of cellular clumps or bulbil-like structures, which are characteristic of Papulaspora. The isolates failed to form sexual fruit bodies and ascospores remained absent, which is an unusual feature for the generally ascosporulating genera Chaetomium and Subramaniula; minute conidia from phialides were sometimes observed.
Tarek A A Moussa - One of the best experts on this subject based on the ideXlab platform.
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Chaetomium like fungi causing opportunistic infections in humans a possible role for extremotolerance
Fungal Diversity, 2016Co-Authors: Deanna A. Sutton, X.w. Wang, Sarah A Ahmed, Z U Khan, Tarek A A Moussa, Hassan S Alzahrani, Omar A Almaghrabi, Suhail AhmadAbstract:Members of the family Chaetomiaceae are ubiquitous ascosporulating fungi commonly, which reside in soil enriched with manure or cellulosic materials. Their role as human pathogens is largely ignored. However, the ability of some species to grow at high temperature enables them to play an important role as opportunistic pathogens. The family contains several genera and species that have never been reported to cause human infection. Hereby, three new species are described; two belong to the genus Subramaniula and one represents a Chaetomium species. Subramaniula asteroides was isolated from various sources including eye and skin infections as well as from the natural environment, and S. obscura was isolated from a toe infection. Chaetomium anamorphosum was isolated from a kidney transplant patient suffering from fungal peritonitis. All species described were previously misidentified as Papulaspora spp. due to the formation of cellular clumps or bulbil-like structures, which are characteristic of Papulaspora. The isolates failed to form sexual fruit bodies and ascospores remained absent, which is an unusual feature for the generally ascosporulating genera Chaetomium and Subramaniula; minute conidia from phialides were sometimes observed.
Josep Guarro - One of the best experts on this subject based on the ideXlab platform.
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Three new species of Chaetomium from soil.
Mycologia, 2017Co-Authors: Kendra Rodríguez, Alberto M. Stchigel, Josep GuarroAbstract:Chaetomium macrostiolatum sp. nov., Chaetomium olivicolor sp. nov. and Chaetomium tarraconensis sp. nov. isolated from Nigerian, Indian, and Spanish soils respectively, are described and illustrated. The first species is characterized by ascomata with a very broad ostiole and yellow hairs, and limoniform ascospores; the second by its thermotolerant growth, inconspicuous and short straight ascomatal hairs and fusiform ascospores; and the last by its unusual, irregularly-shaped ascospores and subglobose ascomata with flexuous to undulate, unbranched ascomatal hairs.
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Invasive Mycotic Infections Caused by Chaetomium perlucidum, a New Agent of Cerebral Phaeohyphomycosis
Journal of Clinical Microbiology, 2003Co-Authors: Michelle A. Barron, Deanna A. Sutton, Michael G. Rinaldi, Josep Guarro, R. Veve, Elizabeth H. Thompson, P. J. Cagnoni, K. Moultney, Nancy E. MadingerAbstract:We report the first two cases of invasive human mycoses caused by the phaeoid ascomycete, Chaetomium perlucidum, and review the English literature regarding invasive Chaetomium infections. Fatal disseminated disease involving the brain, heart, lungs, and spleen is described in an acute myelogenous leukemia patient. A second patient with a history of asthma and chronic bronchiectasis experiencing right-middle-lobe syndrome grew C. perlucidum from lung tissue. This study adds C. perlucidum to the list of other known neurotropic Chaetomium species, C. atrobrunneum and C. strumarium, and also documents this organism's ability to disseminate beyond the central nervous system.
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In Vitro Activities of New Antifungal Agents against Chaetomium spp. and Inoculum Standardization
Antimicrobial Agents and Chemotherapy, 2003Co-Authors: Carolina Serena, Montserrat Ortoneda, Javier Capilla, F. Javier Pastor, Deanna A. Sutton, Michael G. Rinaldi, Josep GuarroAbstract:Chaetomium is an unusual etiological agent of human infections, but the mortality rate among immunocompromised patients is considerably greater than that among nonimmunocompromised individuals. We investigated the in vitro antifungal susceptibilities to novel antifungal agents of 19 strains belonging to three species of Chaetomium which have been involved in human infections, i.e., Chaetomium globosum, C. atrobrunneum, and C. nigricolor, and one strain of the closely related species AChaetomium strumarium. A modification of the NCCLS reference microdilution method (M38-A) was used to evaluate the in vitro activities of ravuconazole, voriconazole, albaconazole, and micafungin. Micafungin was not active at all, while the geometric mean MICs and minimum effective concentrations of the three triazoles were less than 0.5 and 0.4 μg/ml, respectively.