Pub Date : 2022-01-27DOI: 10.5772/intechopen.98780
M. Rai, I. Gupta, S. Bonde, Pramod Ingle, Sudhir S. Shende, Swapnil Gaikwad, M. Razzaghi-Abyaneh, A. Gade
There is a great demand for green methods of synthesis of nanoparticles. Fungi play an important role in the synthesis of nanoparticles, of which Aspergillus spp. are known to secrete different enzymes responsible for the synthesis of nanoparticles. The process of biosynthesis of nanoparticles is simple, rapid, cost-effective, eco-friendly, and easy to synthesize at ambient temperature and pressure. Mostly, the metal nanoparticles such as silver, gold, lead and the oxides of titanium, zinc, and copper are synthesized from Aspergillus spp. These include mainly Aspergillus fumigatus, A. flavus, A. niger, A. terreus, and A. clavatus. The fabrication of different nanoparticles is extracellular. In the present chapter, we have discussed the role of different species of Aspergillus, mechanism of biogenic synthesis particularly enzymes involved in the reduction of metal ions into nanoparticles. The biogenically synthesized nanoparticles have demonstrated several biomedicals, agricultural, and engineering applications. The biogenic nanoparticles are mostly used as antimicrobial and cytotoxic agents. Their use as fungicidal agents is important for sustainable agriculture.
{"title":"Industrial Applications of Nanomaterials Produced from Aspergillus Species","authors":"M. Rai, I. Gupta, S. Bonde, Pramod Ingle, Sudhir S. Shende, Swapnil Gaikwad, M. Razzaghi-Abyaneh, A. Gade","doi":"10.5772/intechopen.98780","DOIUrl":"https://doi.org/10.5772/intechopen.98780","url":null,"abstract":"There is a great demand for green methods of synthesis of nanoparticles. Fungi play an important role in the synthesis of nanoparticles, of which Aspergillus spp. are known to secrete different enzymes responsible for the synthesis of nanoparticles. The process of biosynthesis of nanoparticles is simple, rapid, cost-effective, eco-friendly, and easy to synthesize at ambient temperature and pressure. Mostly, the metal nanoparticles such as silver, gold, lead and the oxides of titanium, zinc, and copper are synthesized from Aspergillus spp. These include mainly Aspergillus fumigatus, A. flavus, A. niger, A. terreus, and A. clavatus. The fabrication of different nanoparticles is extracellular. In the present chapter, we have discussed the role of different species of Aspergillus, mechanism of biogenic synthesis particularly enzymes involved in the reduction of metal ions into nanoparticles. The biogenically synthesized nanoparticles have demonstrated several biomedicals, agricultural, and engineering applications. The biogenic nanoparticles are mostly used as antimicrobial and cytotoxic agents. Their use as fungicidal agents is important for sustainable agriculture.","PeriodicalId":382756,"journal":{"name":"The Genus Aspergillus - Pathogenicity, Mycotoxin Production and Industrial Applications [Working Title]","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128220892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-25DOI: 10.5772/intechopen.98782
Shreya Singh, R. Kanaujia, S. Rudramurthy
Aspergillus species are ubiquitous saprophytes and opportunistic pathogens causing wide spectrum of diseases in humans depending on the host immune status. Following pathogen entry, various soluble bronchopulmonary factors enhance conidial clearance. However, due to virulence factors and poor host immune response Aspergillus conidia bind and damage the airway epithelium. The host immune cells like neutrophils and macrophages recognise Aspergillus spp. through various pathogen recognition receptors and form reactive oxygen species which mediate conidial killing. Neutrophils also attack extracellular hyphae by oxidative attack, non-oxidative granule proteins and neutrophil extracellular traps. In case of adaptive immunity, Th1 cells are crucial sources of IFN-γ mediated protective immunity. The Th17 also display a highly pro-inflammatory which is counterbalanced by a Treg cell. B cells and antibodies also enhance fungal clearance although excessive IgE production may result in atopy. The immune responses are influenced by changes in production of short-chain fatty acids by the gut microbiome which primes cells toward Th2 responses, and this is synchronized by the Innate lymphoid cells. This review provides comprehensive knowledge of various virulence factors of Aspergillus, antifungal host defences including innate and humoral immune response and regulation of host immunity by microbiome.
{"title":"Immunopathogenesis of Aspergillosis","authors":"Shreya Singh, R. Kanaujia, S. Rudramurthy","doi":"10.5772/intechopen.98782","DOIUrl":"https://doi.org/10.5772/intechopen.98782","url":null,"abstract":"Aspergillus species are ubiquitous saprophytes and opportunistic pathogens causing wide spectrum of diseases in humans depending on the host immune status. Following pathogen entry, various soluble bronchopulmonary factors enhance conidial clearance. However, due to virulence factors and poor host immune response Aspergillus conidia bind and damage the airway epithelium. The host immune cells like neutrophils and macrophages recognise Aspergillus spp. through various pathogen recognition receptors and form reactive oxygen species which mediate conidial killing. Neutrophils also attack extracellular hyphae by oxidative attack, non-oxidative granule proteins and neutrophil extracellular traps. In case of adaptive immunity, Th1 cells are crucial sources of IFN-γ mediated protective immunity. The Th17 also display a highly pro-inflammatory which is counterbalanced by a Treg cell. B cells and antibodies also enhance fungal clearance although excessive IgE production may result in atopy. The immune responses are influenced by changes in production of short-chain fatty acids by the gut microbiome which primes cells toward Th2 responses, and this is synchronized by the Innate lymphoid cells. This review provides comprehensive knowledge of various virulence factors of Aspergillus, antifungal host defences including innate and humoral immune response and regulation of host immunity by microbiome.","PeriodicalId":382756,"journal":{"name":"The Genus Aspergillus - Pathogenicity, Mycotoxin Production and Industrial Applications [Working Title]","volume":"30 13","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120858823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.5772/intechopen.99003
M. Reverberi, M. Beccaccioli, M. Zaccaria
Aspergillus section Flavi produce the aflatoxins, secondary metabolites toxic to humans and animals. Why do these fungi produce aflatoxins? They do not have a clear role in pathogenicity or in niche competition. Aspergillus employs a considerable amount of energy to synthesize them: more than 20 enzymatic catalyzes are needed. Within the A. flavus species, all opportunistic pathogens of maize, more than half of the natural population are atoxigenic, indicating that aflatoxins are not so obviously linked to an enhancement of population fitness. The perspective changes in A. parasiticus, pathogen to peanuts, where more than 90% of the natural population produce the four aflatoxins. In this chapter, we aim to discuss our recent hypothesis that aflatoxins act as antioxidants providing more time to Aspergillus to “escape” an exploited substrate, that in the meanwhile is “fully charged” with reactive oxygen species and oxylipins.
{"title":"The Role of Aflatoxins in Aspergillus flavus Resistance to Stress","authors":"M. Reverberi, M. Beccaccioli, M. Zaccaria","doi":"10.5772/intechopen.99003","DOIUrl":"https://doi.org/10.5772/intechopen.99003","url":null,"abstract":"Aspergillus section Flavi produce the aflatoxins, secondary metabolites toxic to humans and animals. Why do these fungi produce aflatoxins? They do not have a clear role in pathogenicity or in niche competition. Aspergillus employs a considerable amount of energy to synthesize them: more than 20 enzymatic catalyzes are needed. Within the A. flavus species, all opportunistic pathogens of maize, more than half of the natural population are atoxigenic, indicating that aflatoxins are not so obviously linked to an enhancement of population fitness. The perspective changes in A. parasiticus, pathogen to peanuts, where more than 90% of the natural population produce the four aflatoxins. In this chapter, we aim to discuss our recent hypothesis that aflatoxins act as antioxidants providing more time to Aspergillus to “escape” an exploited substrate, that in the meanwhile is “fully charged” with reactive oxygen species and oxylipins.","PeriodicalId":382756,"journal":{"name":"The Genus Aspergillus - Pathogenicity, Mycotoxin Production and Industrial Applications [Working Title]","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124601114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-20DOI: 10.5772/intechopen.98897
Cameron K. Tebbi, I. Kotta-Loizou, Robert H.A. Coutts
Carcinogenic effects of Aspergillus spp. have been well established and generally attributed to a variety of mycotoxin productions, particularly aflatoxins. It is known that most carcinogenic mycotoxins, with the exception of fumonisins, are genotoxic and mutagenic, causing chromosomal aberrations, micronuclei, DNA single-strand breaks, sister chromatid exchange, unscheduled DNA synthesis etc. Some Aspergillus spp. are infected with mycoviruses which can result in loss of aflatoxin production. The effects of mycovirus containing Aspergillus on human health have not been fully evaluated. Recent studies in patients with acute lymphoblastic leukemia, in full remission, have revealed the existence of antibody to the products of a certain Aspergillus flavus isolate which harbored an unknown mycovirus. Exposure of blood mononuclear cells from these patients, but not controls, to the products of this organism had reproduced cell surface phenotypes and genetic markers, characteristic of acute lymphoblastic leukemia. Carcinogenic effects of Aspergillus spp. may not always be mycotoxin related and this requires further investigation.
{"title":"Mycovirus Containing Aspergillus flavus and Acute Lymphoblastic Leukemia: Carcinogenesis beyond Mycotoxin Production","authors":"Cameron K. Tebbi, I. Kotta-Loizou, Robert H.A. Coutts","doi":"10.5772/intechopen.98897","DOIUrl":"https://doi.org/10.5772/intechopen.98897","url":null,"abstract":"Carcinogenic effects of Aspergillus spp. have been well established and generally attributed to a variety of mycotoxin productions, particularly aflatoxins. It is known that most carcinogenic mycotoxins, with the exception of fumonisins, are genotoxic and mutagenic, causing chromosomal aberrations, micronuclei, DNA single-strand breaks, sister chromatid exchange, unscheduled DNA synthesis etc. Some Aspergillus spp. are infected with mycoviruses which can result in loss of aflatoxin production. The effects of mycovirus containing Aspergillus on human health have not been fully evaluated. Recent studies in patients with acute lymphoblastic leukemia, in full remission, have revealed the existence of antibody to the products of a certain Aspergillus flavus isolate which harbored an unknown mycovirus. Exposure of blood mononuclear cells from these patients, but not controls, to the products of this organism had reproduced cell surface phenotypes and genetic markers, characteristic of acute lymphoblastic leukemia. Carcinogenic effects of Aspergillus spp. may not always be mycotoxin related and this requires further investigation.","PeriodicalId":382756,"journal":{"name":"The Genus Aspergillus - Pathogenicity, Mycotoxin Production and Industrial Applications [Working Title]","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130791659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-17DOI: 10.5772/intechopen.98509
A. Thammahong
Aspergillus species are ubiquitous fungi found in the environment worldwide. The most common Aspergillus species causing diseases in humans are A. fumigatus, A. flavus, A. niger, and A. terreus. However, species causing human infections are also depending on human immune status. Host immune status and previous underlying diseases are important factors leading to different clinical manifestations and different disease spectra of Aspergillus infections. The most severe form of Aspergillus infections is invasive aspergillosis in human tissue, especially invasive pulmonary aspergillosis (IPA), which has high morbidity and mortality in immunocompromised patients. ICU patients with influenza infections and COVID-19 infections are recently risk factors of invasive pulmonary aspergillosis. New diagnostic criteria include galactomannan antigen assays, nucleic acid amplification assays, and lateral flow assays for early and accurate diagnosis. Voriconazole and the newest azole, isavuconazole, are antifungals of choice in IPA. Nevertheless, azole-resistant Aspergillus strains are increasing throughout the world. The etiology and spreading of azole-resistant Aspergillus strains may originate from the widespread use of fungicides in agriculture, leading to the selective pressure of azole-resistant strains. Therefore, there is a necessity to screen Aspergillus antifungal susceptibility patterns for choosing an appropriate antifungal agent to treat these invasive infections. In addition, mutations in an ergosterol-producing enzyme, i.e., lanosterol 14-α demethylase, could lead to azole-resistant strains. As a result, the detection of these mutations would predict the resistance to azole agents. Although many novel azole agents have been developed for invasive Aspergillus infections, the rate of novel antifungal discovery is still limited. Therefore, better diagnostic criteria and extensive antifungal resistant Aspergillus screening would guide us to better manage invasive Aspergillus infections with our existing limited resources.
{"title":"Aspergillus-Human Interactions: From the Environment to Clinical Significance","authors":"A. Thammahong","doi":"10.5772/intechopen.98509","DOIUrl":"https://doi.org/10.5772/intechopen.98509","url":null,"abstract":"Aspergillus species are ubiquitous fungi found in the environment worldwide. The most common Aspergillus species causing diseases in humans are A. fumigatus, A. flavus, A. niger, and A. terreus. However, species causing human infections are also depending on human immune status. Host immune status and previous underlying diseases are important factors leading to different clinical manifestations and different disease spectra of Aspergillus infections. The most severe form of Aspergillus infections is invasive aspergillosis in human tissue, especially invasive pulmonary aspergillosis (IPA), which has high morbidity and mortality in immunocompromised patients. ICU patients with influenza infections and COVID-19 infections are recently risk factors of invasive pulmonary aspergillosis. New diagnostic criteria include galactomannan antigen assays, nucleic acid amplification assays, and lateral flow assays for early and accurate diagnosis. Voriconazole and the newest azole, isavuconazole, are antifungals of choice in IPA. Nevertheless, azole-resistant Aspergillus strains are increasing throughout the world. The etiology and spreading of azole-resistant Aspergillus strains may originate from the widespread use of fungicides in agriculture, leading to the selective pressure of azole-resistant strains. Therefore, there is a necessity to screen Aspergillus antifungal susceptibility patterns for choosing an appropriate antifungal agent to treat these invasive infections. In addition, mutations in an ergosterol-producing enzyme, i.e., lanosterol 14-α demethylase, could lead to azole-resistant strains. As a result, the detection of these mutations would predict the resistance to azole agents. Although many novel azole agents have been developed for invasive Aspergillus infections, the rate of novel antifungal discovery is still limited. Therefore, better diagnostic criteria and extensive antifungal resistant Aspergillus screening would guide us to better manage invasive Aspergillus infections with our existing limited resources.","PeriodicalId":382756,"journal":{"name":"The Genus Aspergillus - Pathogenicity, Mycotoxin Production and Industrial Applications [Working Title]","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129151302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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