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MALDI-TOF ICMS as a modern approach to identify potential aflatoxigenic fungi

Rodrigues, Paula; Santos, Cledir; Venâncio, Armando; Lima, Nelson
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
36.28%
The Aspergillus section Flavi is among the best studied fungi, having different commercial applications, but also causing biodeterioration of commodities and food spoilage. Fungi from this Section are also responsible for the production of highly toxic secondary metabolites – the aflatoxins. They are morphologically and genetically very similar, and can be difficult to differentiate by both cultural and molecular biology methods. Besides that, new species are continuously being described in this Section. A reliable identification typically implies the analyses of a variety of morphological, biochemical and molecular traits. Recently, Matrix-Assisted Laser Desorption/Ionisation Time-Of-Flight Intact Cell Mass Spectrometry (MALDI-TOF ICMS) has been used to generate spectra of protein masses in a range of 2,000 to 20,000 Da that are a taxa specific fingerprinting. This technique has already shown high potentialities to discriminate very closely related taxa and, it has been used as a new tool in the polyphasic approach to identify potential aflatoxigenic fungi. Aim: This work aims to validate the MALDI-TOF ICMS technique on Aspergillus Section Flavi identification. As a matter of consequence, obtained results by spectral analysis were compared to those obtained by morphological...

Characterization and identification of aspergillus section flavi isolates from portuguese almonds using a polyphasic approach including MALDI-TOF ICMS

Rodrigues, Paula; Santos, Cledir; Venâncio, Armando; Lima, Nelson
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
46.15%
Aspergillus is a large genus, with a complex and ever evolving taxonomy. Section Flavi is one of the most significant sections in the genus, and is one of the best studied among fungi, for the numerous industrial applications as well as for food safety issues. Section Flavi is composed of a large number of very closely related species. While these species are difficult to differentiate morphologically and even genetically, they differ in a characteristic that is of paramount importance for food safety, as some are responsible for the production of the highly toxigenic aflatoxins. Taxonomy and species identification are therefore subject of great interest for scientists aiming to clarify the species concept and limits within the section. In this sense, the establishment of schemes for species and for aflatoxigenic strains identification that are simultaneously accurate, sensitive, robust and expedite is mandatory. At present, reliable identification schemes typically imply the analysis of a wide variety of morphological, biochemical and molecular traits. Recently, Matrix-Assisted Laser Desorption/Ionisation Time-Of-Flight Intact Cell Mass Spectrometry (MALDI-TOF ICMS) has been used to generate spectra of protein masses in a range of 2...

MALDI-TOF MS: improved methods for the identification/characterisation and authentication of fungal strains

Santos, Cledir; Rodrigues, Paula; Venâncio, Armando; Lima, Nelson
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
46.26%
The identification of species is an important goal in taxonomic mycology. Information about each fungus (e.g. morphological description, physiological and biochemical properties, ecological roles, and societal risks or benefits) is key element in this process. Identifications can be a long and seemingly never-ending process with frequent revisions of the taxonomic schemes. These changes make identifications even more complicated for the non-specialised researchers as each taxonomic group has specialised literature, terminology and characters. This occurs to the extent that identifications can only be undertaken by a narrow group of scientists especially skilled in the “art”, which can make the procedures appear to be subjective. Aspergillus is a large fungal genus, with a complex and ever evolving taxonomy. Section Flavi is one of the most significant sections in this genus. Taxonomy and species identification is subject of great interest for scientists aiming to clarify the species concept and limits within the section. Furthermore, this section comprises both toxigenic and non-toxigenic species/strains, with great interest to biotechnology and food industry. In the present study, from 352 isolates of Aspergillus section Flavi obtained from Portuguese almonds and identified based on morphological...

Characterization of fungal soil communities by F-RISA and arbuscular mycorrhizal fungi from Araucaria angustifolia forest soils after replanting and wildfire disturbances

PATREZE, C. M.; PAULO, E. N. De; MARTINELLI, A. P.; CARDOSO, E. J. B.; TSAI, S. M.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.07%
The Fungal Ribosomal Intergenic Spacer Analysis (F-RISA) was used to characterize soil fungal communities from three ecosystems of Araucaria angustifolia from Brazil: a native forest and two replanted forest ecosystems, one of them with a past history of wildfire. The arbuscular mycorrhizal fungi (AMF) infection was evaluated in Araucaria roots of 18-month-old axenic plants previously inoculated with soils collected from those areas in a greenhouse experiment. The principal component analysis of F-RISA profiles showed different soil fungal community between the three studied areas. Sixty three percent of F-RISA fragments amplified in the soil and the substrate samples presented lengths between 500 and 700 bp. The number of Operational Taxonomic Units (OTUs) was 34 for soil and 38 for substrate, however, more fragments were detected in soil (214) than in substrate (163). An in silico F-RISA analysis to compare our data with ITS1-5.8S-ITS2 sequences from NCBI database showed the presence of Ascomycota, Basidiomycota and Glomeromycota among the soil and substrate fungal communities. AMF infection was higher in plants inoculated with soil from the native forest and the replanted forest with wildfire, both presenting similar chemical characteristics but with different disturbance levels. These results indicate that soil chemical composition may influence the soil fungal community structures rather than the anthropogenic or fire disturbances.

Validação de uma metodologia molecular para identificação de fungos e investigação in vitro da transição dimórfica em Candida albicans; Validation of a molecular method for identification of fungi and in vitro investigation of the dimorphic transition in Candida albicans

Mota, Adolfo José da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/04/2012 PT
Relevância na Pesquisa
45.88%
A classificação de fungos microscópicos é limitada pela escassez de detalhes morfológicos e incertezas na caracterização bioquímica. Nesse trabalho desenvolvemos um método simples, baseado na amplificação de um segmento de cerca de 2.800 bares de bases seguida de digestão com DdeI e análise do padrão após eletroforese em agarose. Demonstramos que o método discrimina tão bem quanto a sequência de DNA do segmento após analisar mais de 400 amostras que foram classificadas em 33 espécies. Essa tecnologia facilita a busca por novos representantes da imensa diversidade existente, espécies que podem ser exploradas quanto ao seu valor potencial para a medicina e a indústria. Outras metodologias moleculares foram desenvolvidas para discriminar entre espécies próximas e na identificação de novas espécies. Em seguida, o trabalho esteve voltado para o desenvolvimento de um ensaio laboratorial que nos permitisse estudar a transição dimórfica em Candida albicans. Desenvolvemos dois novos ensaios, um biológico e outro sobre membrana artificial, para estudar a indução ou inibição da produção de hifas. A expressão de genes associados ao processo foi acompanhada de maneira quantitativa. Fracionando cromatograficamente o soro fetal bovino...

Analysis of inteins in the Candida parapsilosis complex for simple and accurate species identification

Prandini, Tâmara Heloísa Rocha; Theodoro, Raquel Cordeiro; Bruder-Nascimento, Ariane C. M. O.; Scheel, Christina M.; Bagagli, Eduardo
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 2830-2836
ENG
Relevância na Pesquisa
36.08%
Inteins are coding sequences that are transcribed and translated with flanking sequences and then are excised by an autocatalytic process. There are two types of inteins in fungi, mini-inteins and full-length inteins, both of which present a splicing domain containing well-conserved amino acid sequences. Full-length inteins also present a homing endonuclease domain that makes the intein a mobile genetic element. These parasitic genetic elements are located in highly conserved genes and may allow for the differentiation of closely related species of the Candida parapsilosis (psilosis) complex. The correct identification of the three psilosis complex species C. parapsilosis, Candida metapsilosis, and Candida orthopsilosis is very important in the clinical setting for improving antifungal therapy and patient care. In this work, we analyzed inteins that are present in the vacuolar ATPase gene VMA and in the threonyl-tRNA synthetase gene ThrRS in 85 strains of the Candida psilosis complex (46 C. parapsilosis, 17 C. metapsilosis, and 22 C. orthopsilosis). Here, we describe an accessible and accurate technique based on a single PCR that is able to differentiate the psilosis complex based on the VMA intein. Although the ThrRS intein does not distinguish the three species of the psilosis complex by PCR product size...

Filamentous fungal characterizations by matrix-assisted laser desorption⁄ionization time-of-flight mass spectrometry

Santos, C.; Paterson, R. R. M.; Venâncio, Armando; Lima, Nelson
Fonte: The Society for Applied Microbiology Publicador: The Society for Applied Microbiology
Tipo: Artigo de Revista Científica
Publicado em /02/2010 ENG
Relevância na Pesquisa
46.12%
Matrix-assisted laser desorption ⁄ ionization time-of-flight intact cell mass spectrometry (MALDI-TOF ICMS) is coming of age for the identification and characterization of fungi. The procedure has been used extensively with bacteria. UV-absorbing matrices function as energy mediators that transfer the absorbed photoenergy from an irradiation source to the surrounding sample molecules, resulting in minimum fragmentation. A surprisingly high number of fungal groups have been studied: (i) the terverticillate penicillia, (ii) aflatoxigenic, black and other aspergilli, (iii) Fusarium, (iv) Trichoderma, (iv) wood rotting fungi (e.g. Serpula lacrymans) and (v) dermatophytes. The technique has been suggested for optimizing quality control of fungal Chinese medicines (e.g. Cordyceps). MALDI-TOF ICMS offers advantages over PCR. The method is now used in taxonomic assessments (e.g. Trichoderma) as distinct from only strain characterization. Low and high molecular mass natural products (e.g. peptaibols) can be analysed. The procedure is rapid and requires minimal pretreatment. However, issues of reproducibility need to be addressed further in terms of strains of species tested and between run variability. More studies into the capabilities of MALDI-TOF ICMS to identify fungi are required.; Fundação para a Ciência e a Tecnologia (FCT); IOI Professorial Chair...

Fourier transform infrared as a powerful technique for the identification and characterization of filamentous fungi and yeasts

Santos, C.; Fraga, Marcelo E.; Kozakiewicz, Z.; Lima, Nelson
Fonte: Elsevier Masson SAS. Publicador: Elsevier Masson SAS.
Tipo: Artigo de Revista Científica
Publicado em /03/2010 ENG
Relevância na Pesquisa
45.92%
Fourier transform infrared is considered a powerful technique for characterizing chemical compositions of complex probes such as microorganisms. It has successfully been applied to fungal identification. In this paper, the current state of identification and characterization of filamentous fungi and yeasts by Fourier transform infrared is reviewed.; European Community - Seventh Framework Program (FP7,2007-2013); Research Infrastructures Action -grant agreement No. FP7-228310 (EMbaRC project)

Barcoding of entomopathogenic fungi from olive tree pests : prospects and limitations

Oliveira, Ivo Vaz; Pereira, J. A.; Bento, Albino; Baptista, Paula; Neto, T. Lino
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2011 ENG
Relevância na Pesquisa
46.29%
From all the barcoding initiatives in progress, fungal barcode is probably the one where more difficulties have been encountered. While for plants and animais the barcode regions were easy to define, for fungi the choice was not so straightforward. The internal transcribed spacer (ITS) region was one of the proposed DNA regions for barcoding fungi. This is an extensively used region, for molecular systematic and identification of species, being probably the most widely sequenced DNA region of fungi. This is due to the simplicity of the amplification, related to the multicopy nature of the rDNA; the possibility of using universal primers; and the high levei of sequence variation that occurs even between closely related species. Furthermore, a significant number of identified sequences for comparison are available in the GenBank database. Although the ITS region of rDNA was chosen for some groups of fungi, the use of this region presents very limited application for others, especially for Ascomycetes. As some of the most important entomopathogenic fungi are Ascomycetes, belonging to genera Beauveria, Cordyceps, Isaria, Lecanicillium and Paecilomyces, the use of the ITS region for barcoding purpose are being complemented with other regions. This work...

MALDI-TOF MS : improved methods for the identification/characterisation and authentication of fungal strains

Santos, C; Rodrigues, P.; Venâncio, Armando; Lima, Nelson
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em 04/01/2012 ENG
Relevância na Pesquisa
46.26%
The identification of species is an important goal in taxonomic mycology. Information about each fungus (e.g. morphological description, physiological and biochemical properties, ecological roles, and societal risks or benefits) is key element in this process. Identifications can be a long and seemingly never-ending process with frequent revisions of the taxonomic schemes. These changes make identifications even more complicated for the non-specialised researchers as each taxonomic group has specialised literature, terminology and characters. This occurs to the extent that identifications can only be undertaken by a narrow group of scientists especially skilled in the “art”, which can make the procedures appear to be subjective. Aspergillus is a large fungal genus, with a complex and ever evolving taxonomy. Section Flavi is one of the most significant sections in this genus. Taxonomy and species identification is subject of great interest for scientists aiming to clarify the species concept and limits within the section. Furthermore, this section comprises both toxigenic and non-toxigenic species/strains, with great interest to biotechnology and food industry. In the present study, from 352 isolates of Aspergillus section Flavi obtained from Portuguese almonds and identified based on morphological...

Identification of Brazilian wild-type isolates of Aspergillus fumigatus based on polyphasic approach including MALDI-TOF MS technique

Lima, M. Sanitá; Santos, Cledir; Lima, Nelson; Polizeli, M.L.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2012 ENG
Relevância na Pesquisa
36.28%
Currently is accpeted that the majority of the unknown species in the world are in the tropics and Brazil possibly holds more than 25% of this biodiversity. In the filamentous fungi case the number of new species described for science in Brazil is very small when compared with the potentiality of the region. In addition, there is expected to find a large biological variability inside of described and new fungal species. Species belonging to the Aspergillus genus are responsible for invasive aspergillosis. This is gaining prominent position because of their capability to affect immunocompromised and immunosuppressed patients and aspergillosis is most commun mould infection more recognised worldwide. A better understanding about the regional fungal traits can help to a fast and effective treatment of patients with aspergillosis. In order to set up a collection containing regional fungal strains with clinical relevance to attend the great variability (morphology, biochemical, genomics and proteomics patterns) of the Brazilian fungal population 13 wild-type Aspergillus isolates from section Fumigati were studied. They were isolated from the five official Brazilian regions (North, Northeast, Centre-east, Southeast and South) and identified based on a polyphasic approach which is. based on morphological...

The importance of a quick identification of Aspergillus niger for a proper mycotoxin related diagnosis

Soares, Célia Maria Gonçalves; Santos, Cledir; Maciel, Marília; Souza-Motta, Cristina; Lima, Nelson; Venâncio, Armando
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2012 ENG
Relevância na Pesquisa
36.1%
Food safety has become an important food quality attribute within the last decade. Moreover, consumers have a better perception about the food contamination with mycotoxins. These secondary metabolites produced by filamentous fungi can cause acute toxic, mutagenic, teratogenic and carcinogenic effects on animals and humans. Mycotoxins can appear in the food chain and are greatly resistant to decomposition or being broken down in digestion. They remain intact in the food chain in livestock and dairy products and even after temperature treatments, such as cooking and freezing. Aspergillus niger aggregate species are commonly found on soil and are pathogenic to several crops. This group of filamentous fungi is formed by a series of morphologically indistinguishable species. Aspergillus niger is one of the species in the aggregate and, apart from its economic value (it is used for industrial purposes), it is also an important mycotoxin producer, such as ochratoxin A (OTA) and, more recently, was described as fumonisin B2 (FB2) producer. Both mycotoxins were evaluated by the International Agency for Research on Cancer (IARC) as “Group 2B carcinogens”, i.e., probably carcinogenic to humans. The continued exposure to these mycotoxins can cause chronic toxicity which is characterised by low-dose exposure over a long time period...

Polyphasic identification of Aspergillus isolates belonging to section Nigri with clinical relevance

Maciel, Marília; Santos, Cledir; Lima, Nelson; Souza-Motta, Cristina
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2012 ENG
Relevância na Pesquisa
36.21%
Aspergillosis is the name of a group of diseases in humans and animals caused by opportunist moulds of the genus Aspergillus. The vast majority of infections are caused by A. fumigatus, followed by other species such as A. flavus, A. terreus and A. niger. Among the pulmonary infection, aspergillosis is gaining prominent position not only in immunocompromised patients, but also in immunosuppressed. The absence of a reliable fungal identification system affects the control of systemic fungal infections. Matrix-Assisted Laser Desorption⁄Ionisation Time-Of- Flight Mass Spectrometry (MALDI-TOF MS) is a spectral technique that analysis the chemical molecular mass of the microbial cellular composition providing rapid and discriminatory fingerprints for identification. This technique starts to have application in clinical laboratories.This work aimed to get a reliable identification of Aspergillus isolates from section Nigri deposited at University of Recife Mycology (URM) culture collection. These materials were used as clinical reference strains to attend the great variability (morphology, biochemical, genomics and proteomics patterns) of the Brazilian fungal population. A polyphasic approach based on morphological, biochemical and spectral analysis by MALDI-TOF MS was applied for the characterisation and identification of 74 Aspergillus isolates from section Nigri deposited at URM. In addition...

Detection and Identification of Fungal Pathogens by PCR and by ITS2 and 5.8S Ribosomal DNA Typing in Ocular Infections

Ferrer, Consuelo; Colom, Francisca; Frasés, Susana; Mulet, Emilia; Abad, José L.; Alió, Jorge L.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2001 EN
Relevância na Pesquisa
36.2%
The goal of this study was to determine whether sequence analysis of internal transcribed spacer/5.8S ribosomal DNA (rDNA) can be used to detect fungal pathogens in patients with ocular infections (endophthalmitis and keratitis). Internal transcribed spacer 1 (ITS1) and ITS2 and 5.8S rDNA were amplified by PCR and seminested PCR to detect fungal DNA. Fifty strains of 12 fungal species (yeasts and molds) were used to test the selected primers and conditions of the PCR. PCR and seminested PCR of this region were carried out to evaluate the sensitivity and specificity of the method. It proved possible to amplify the ITS2/5.8S region of all the fungal strains by this PCR method. All negative controls (human and bacterial DNA) were PCR negative. The sensitivity of the seminested PCR amplification reaction by DNA dilutions was 1 organism per PCR, and the sensitivity by cell dilutions was fewer than 10 organisms per PCR. Intraocular sampling or corneal scraping was undertaken for all patients with suspected infectious endophthalmitis or keratitis (nonherpetic), respectively, between November 1999 and February 2001. PCRs were subsequently performed with 11 ocular samples. The amplified DNA was sequenced, and aligned against sequences in GenBank at the National Institutes of Health. The results were PCR positive for fungal primers for three corneal scrapings...

Diagnosis of Fusarium Infections: Approaches to Identification by the Clinical Mycology Laboratory

van Diepeningen, Anne D.; Brankovics, Balázs; Iltes, Jearidienne; van der Lee, Theo A. J.; Waalwijk, Cees
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.16%
Infections caused by the genus Fusarium have emerged over the past decades and range from onychomycosis and keratitis in healthy individuals to deep and disseminated infections with high mortality rates in immune-compromised patients. As antifungal susceptibility can differ between the different Fusarium species, identification at species level is recommended. Several clinical observations as hyaline hyphae in tissue, necrotic lesions in the skin and positive blood tests with fungal growth or presence of fungal cell wall components may be the first hints for fusariosis. Many laboratories rely on morphological identification, but especially multi-locus sequencing proves better to discriminate among members of the species complexes involved in human infection. DNA-based diagnostic tools have best discriminatory power when based on translation elongation factor 1-α or the RNA polymerase II second largest subunit. However, assays based on the detection of other fusarial cell compounds such as peptides and cell wall components may also be used for identification. The purpose of this review is to provide an overview and a comparison of the different tools currently available for the diagnosis of fusariosis.

Identification of Penicillia species isolated from southern Atlantic Ocean marine sponge using a polyphasic approach including MALDI-TOF ICMS

Passarini, Michel. R. Z.; Santos, C.; Lima, Nelson; Sette, Lara D.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2011 ENG
Relevância na Pesquisa
36.08%
In the last years the research concerning marine microorganisms has increased in number. However, the knowledge about the phylogenetic and diversity of this fungal community is still scarce. The reliable identification of filamentous fungi typically implies the analyses of a variety of morphological, biochemical and molecular traits. Recently, Matrix-Assisted Laser Desorption/Ionisation Time-Of-Flight Intact Cell Mass Spectrometry (MALDl-TOF ICMS) has been used to generate spectra of protein masses in a range from 2000 to 20000 Da that are a taxa specific fingerprinting. This technique has already shown high potentialities to discriminate very dosely related taxa and, it has been used as a new tool in the polyphasic approach to identify this kind of microorganisms. The aim of the present study was investigate the diversity of 19 penicillia isolated from the southern Atlantic Ocean marine sponge Dragmacidon reticulate using a polyphasic approach. The first approach was the sequence of ITS-rDNA gene region and to compare with sequence data available at NCBl-GenBank using BLAST N· The putative penicillia species were further investigated using the phenotypic techniques: macro- and micromorphologies and MALDl-TOF ICMS. From 19 isolates 9 ribotypes were obtained from the sequencing analysis. One ribotype after phenotypic analysis is a clearly new species and the remain ribotypes have their identification confirmed by micro- and macro-morphological and MALDl-TOF ICMS analyses. In conclusions...

Identification of mycotoxigenic fungi from grains in a Nigerian region using the modern polyphasic methodology

Okeke, O. F. I.; Fapohunda, S. O.; Soares, Célia Maria Gonçalves; Lima, Nelson; Ayanbimpe, G. M.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2015 ENG
Relevância na Pesquisa
36.19%
Mycotoxins are poisonous substances produced by fungi which contaminate agricultural commodities. Many foods and feeds can become contaminated with mycotoxins since they can form in commodities before harvest, during the time between harvesting and drying, and in storage. The food crops most often affected include maize, peanuts, sorghum, wheat, cocoa and tree nuts. Mycotoxins may also be carried over to animal products due to consumption of contaminated feed. Maize (Zea mays) and guinea corn (Sorghum bicolor) form a major staple of the study area and are high risk commodities for mycotoxigenic fungi and mycotoxin contamination. Multistage sampling technique was used to select the markets and store/warehouses used for this study; sample collection employed a simple random sampling method from different sampling points within designated areas. Identification of all fungal isolates was carried out using the modern polyphasic methodology for filamentous fungi identification. At the level of phenotypic approach, the mycotoxigenic fungi Aspergillus, Fusarium, and Penicillium were identified. These fungal isolates also produced the mycotoxins Aflatoxins B1 and B2, Fumonisin B1, Cyclopiazonic acid, Ochratoxin A and Ochratoxin alfa. Spectral analysis by MALDI-TOF MS identified the Aspergillus species as A. flavus...

Evaluierung von PCR-Methoden zur Identifizierung und Differenzierung von Erregern der Zygomykose und Aspergillose; Evaluation of PCR methods for discrimination and identification of agents of mucormycosis and aspergillosis

Konrad, Franziska
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
DE_DE
Relevância na Pesquisa
36.22%
Aspergillen und Mucormykosen sind ubiquitär verbreitete Fadenpilze, die bei immunsupprimierten Patienten schwere, oft tödliche, Infektionen hervorrufen können. Der frühzeitigen Diagnostik und Therapie kommt zur Senkung der Letalität eine große praktische Bedeutung zu, wobei die optimale antimykotische Therapie isolat- und speziesabhängig ist. Diese Pilzinfektionen sind mit den bislang zur Verfügung stehenden diagnostischen Mitteln nur unzureichend zu identifizieren und zu differenzieren. Ziel der vorliegenden Promotionsarbeit war die Evaluation zweier semi-nested PCR-Methoden zur Identifizierung und Differenzierung von Erregern der Mucormykosen und Aspergillosen in Paraffin eingebetteten Gewebeproben und nativen Biopsien. Methode Mucormykosen. Als Zielsequenz wurde die 18S rDNA gewählt. Das äußere Primerpaar ZM1: 5'-ATT ACC ATG AGC AAA TCA GA-3' und ZM 2: 5'-TCC GTC AAT TCC TTT AAG TTT C-3' amplifiziert ein 407 bis 408 bp langes Fragment. Bei der semi-nested PCR wird durch ZM 1 und ZM 3: 5'-CAA TCC AAG AAT TTC ACC TCT AG-3' ein 176 bis 177 bp langes Fragment des ersten Produktes begrenzt. Aspergillen. Diese PCR wurde in Anlehnung an die Arbeit von Bretagne et al. (1995) aufgebaut. Sie dient dem Nachweis mitochondrialer Aspergillus-DNA. Mit den Primern P 1: 5'-GAA AGG TCA GGT GTT CGA GTC AC-3' und P 2: 5'-CTT TGG TTG CGG GTT TAG GGA TT-3' wird ein 135 bp langes Fragment der mitochondrialen DNA von Aspergillus spp. amplifiziert. Zur Erhöhung der Sensitivität und Spezifität wurden P 1 und P 2 als semi-nested PCR-Primer verwendet und die Methode um einen äußeren Primer...

Exposição a fungos dos trabalhadores dos ginásios com piscina

Viegas, Carla Sofia Costa
Fonte: Escola Nacional de Saúde Pública. Universidade Nova de Lisboa Publicador: Escola Nacional de Saúde Pública. Universidade Nova de Lisboa
Tipo: Tese de Doutorado
Publicado em //2010 POR
Relevância na Pesquisa
36.31%
RESUMO - Os trabalhadores dos ginásios com piscinas apresentam maior prevalência de lesões fúngicas, como a Tinea pedis e a onicomicose, devido às características intrínsecas da sua actividade profissional, pois apresentam mais horas por dia de exposição à contaminação fúngica das superfícies. Esta situação verifica-se não só por serem os que mais frequentam os locais possíveis de estarem contaminados, como é o caso de balneários, vestiários e zona envolvente às piscinas, mas também porque algumas das actividades desenvolvidas são realizadas com os pés descalços. Além disso, a utilização de roupa sintética e de calçado ocluso, que retêm a sudação excessiva, favorece o desenvolvimento fúngico. Constituiu objectivo deste trabalho conhecer o risco de infecção e/ou lesão (Tinea pedis e onicomicose) nos trabalhadores dos ginásios com piscina e a sua eventual relação com a exposição à contaminação fúngica (ar e superfícies) dos locais de trabalho. Foram descritas as variáveis ambientais e biológicas que influenciam a infecção e/ou lesão fúngica em ambiente profissional e exploradas eventuais associações entre essas mesmas variáveis. Foram também conhecidas as diferenças da contaminação fúngica das superfícies entre as duas principais estações do ano (Verão e Inverno) e entre antes e depois da lavagem e desinfecção. O estudo realizado possui uma componente transversal...

Use of a polyphasic approach including MALDI-TOF MS for identification of Aspergillus section Flavi strains isolated from food commodities in Brazil

Silva, Fernanda Chaves da; Chalfoun, Sara Maria; Batista, Luis Roberto; Santos, C.; Lima, Nelson
Fonte: Universita degli Studi di Milano; Springer Publicador: Universita degli Studi di Milano; Springer
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
Relevância na Pesquisa
46.08%
Brazil is one the largest producers and exporters of food commodities in the world. The evaluation of fungi capable of spoilage and the production mycotoxins in these commodities is an important issue that can be of help in bioeconomic development. The present work aimed to identify fungi of the genus Aspergillus section Flavi isolated from different food commodities in Brazil. Thirty-five fungal isolates belonging to the section Flavi were identified and characterised. Different classic phenotypic and genotypic methodologies were used, as well as a novel approach based on proteomic profiles produced by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Type or reference strains for each taxonomic group were included in this study. Three isolates that presented discordant identification patterns were further analysed using the internal transcribed spacer (ITS) region and calmodulin gene sequences. The data obtained from the phenotypic and spectral analyses divide the isolates into three groups, corresponding to taxa closely related to Aspergillus flavus, Aspergillus parasiticus, and Aspergillus tamarii. Final polyphasic fungal identification was achieved by joining data from molecular analyses...