741 resultados para Aspergillus
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Birds are hosts for a rich fungal microbiota which can act as potent pathogens for humans and other species of animals, causing thereby serious public health problems. The objective of this study was to evaluate the participation of birds kept in containers in the epidemiology of infectious diseases such as cryptococcosis and aspergillosis, thus verifying the maintenance and spread of pathogens in the environment. 36 samples of excretas of passeriformes were collected and were cultivated in Sabouraud Dextrose Agar 4% at room temperature and 37°C. The isolated fungal colonies were classified according to their morphological and staining characteristics. Subsequently, those in yeast form were peaked in Niger Agar, incubated at 30°C. In one sample showed growth of more than one type of colony and there was verified the presence of 25.0% of Penicillium spp., 19.4% of Trichosporon spp., 13.9% of C. gattii, 11.1% of C. neoformans, 11.1% of Candida spp., 8.3% of Rhizomucor spp., 8.3% of Aspergillus spp., 2.8% of Nigrospora spp. and 2,8% of Geotrichum spp. It can be conluded by the expost that birds shed continuously pathogenic microorganisms in their feces acting in definitive form in the infectious diseases ecoepidemiology.
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Paracoccidioidomycosis and aspergillosis are, respectively, mycosis caused by Paracoccidioides brasiliensis and Aspergillus fumigatus fungi, which, most frequently, attack the lungs and later spread to other body regions. The association between both mycosis is rare in patients that do not present immunosuppression. A 49-year-old man presented with oral lesion, besides lesions on palatum, retromolar and oropharyngeal regions. Histopathological and microbiological exams confirmed the diagnosis of paracoccidioidomycosis associated to aspergillosis. Historically, fungi have been considered as the cause of relatively important infections, but, in the last years, a significant increase of diseases caused by fungi is evidenced. The recognition of the etiological agent in culture is important for the suitable treatment, once these fungi can cause irreversible damages or even death. The purpose of this study was to demonstrate, through the case of a patient who presented both mycosis associated, the need of complementary exams for the diagnosis of oral diseases, when routine laboratorial exams indicate the presence of another disease associated.
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The objective of this work was to evaluate the preservative effectiveness of liquid crystalline systems containing retynil palmitate (RP) by the challenge test (CT) and D-value. A system was developed containing water, silicon glycol copolymer, and polyether functional siloxane with 1% RP added. The analyses were carried out by methods in the U.S. Pharmacopeia (USP 31, 2008) using the microorganisms Escherichia coli, Staphylococcus aureus,Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. The CT showed that after 7 days, all microorganisms were eliminated except A. niger, which maintained viability for at least 28 days after inoculation. Moreover, the microorganisms E. coli, P. aeruginosa, S. aureus, C. albicans and A. niger presented different growth behaviors, evidenced by differences among the D-values calculated. It was concluded that the CT and D-value were efficient methods for evaluation of the preservative property of these formulations.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The purpose of treating seeds chemically is to eradicate their pathogens and/or protect them against soil pathogens, mainly by germination time. However, there is little research on vegetables investigating the effect of this treatment on seed quality. Therefore, this study evaluates the effects of Carboxin + Thiram doses on germination and vigor of three lots of broccoli seeds, as well as on the incidence of fungi in treated seed. The 15 treatments were evaluated in a factorial system (3x5), with the first factor consisting of three lots of 'Avenger' broccoli seeds (lots 82744, 82745 and 82749), and the second factor consisting of five doses (0, 0.04, 0.06, 0.10 and 0.12% of a.i.) of Carboxin + Thiram fungicide (commercial name Vitavax-Thiran). The germination and seed vigor were evaluated, in addition to the presence of pathogens in seeds after treatment (blotter test). All lots showed high levels of germination and vigor. The lot 82749, however, showed higher value in plug test in substrate emergence (99%) than lot 82745 (95%). Regarding the treatment with Carboxin + Thiram, no changes in germination average (98%) and vigor were noticed (average for the first germination count, length, and dry weight of seedling, plug test at 10 days after sowing of 97%, 4.9 cm, 4.0 mg and 96%, respectively), showing that this fungicide, in the evaluated doses, does not affect the quality of broccoli seeds. As to seeds health, the pathogens Alternaria spp. and Fusarium spp. were detected, in addition to saprophytic species such as Penicillium, Aspergillus, Trichoderma, and Rhizopus. The higher incidence of Fusarium spp. was noticed in lot 82744, and the lowest in lot 82749. As to Penicillium spp., lot 82479 was the most contaminated. Regarding other fungi, the general incidence was very low and there was no difference between lots and doses used.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC
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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC
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The filamentous fungus Paecylomices variotii was able to produce high levels of cell extract and extracellular invertases when grown under submerged fermentation (SbmF) and solid-state fermentation, using agroindustrial products or residues as substrates, mainly soy bran and wheat bran, at 40A degrees C for 72 h and 96 h, respectively. Addition of glucose or fructose (a parts per thousand yen1%; w/v) in SbmF inhibited enzyme production, while the addition of 1% (w/v) peptone as organic nitrogen source enhanced the production by 3.7-fold. However, 1% (w/v) (NH4)(2)HPO4 inhibited enzyme production around 80%. The extracellular form was purified until electrophoretic homogeneity (10.5-fold with 33% recovery) by DEAE-Fractogel and Sephacryl S-200 chromatography. The enzyme is a monomer with molecular mass of 102 kDa estimated by SDS-PAGE with carbohydrate content of 53.6%. Optima of temperature and pH for both, extracellular and cell extract invertases, were 60A degrees C and 4.0-4.5, respectively. Both invertases were stable for 1 h at 60A degrees C with half-lives of 10 min at 70A degrees C. Mg2+, Ba2+ and Mn2+ activated both extracellular and cell extract invertases from P. variotii. The kinetic parameters K-m and V-max for the purified extracellular enzyme corresponded to 2.5 mM and 481 U/mg prot(-1), respectively.
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The scanning electron microscopy (SEM) analysis showed that whole living hyphal of marine fungi Aspergillus sclerotiorum CBMAI 849 and Penicillium citrinum CBMAI 1186 were immobilized on support matrices of silica gel, silica xerogel and/or chitosan. P. citrinum immobilized on chitosan catalyzed the quantitative reduction of 1-(4-methoxyphenyl)-ethanone (1) to the enantiomer (S)-1-(4-methoxyphenyl)-ethanol (3b), with excellent enantioselectivity (ee > 99%, yield = 95%). Interestingly, ketone 1 was reduced with moderate selectivity and conversion to alcohol 3b (ee = 69%, c 40%) by the free mycelium of P. citrinum. This free mycelium of P. citrinum catalyzed the production of the (R)-alcohol 3a, the antipode of the alcohol produced by the immobilized cells. P. citrinum immobilized on chitosan also catalyzed the bioreduction of 2-chloro-1-phenylethanone (2) to 2-chloro-1-phenylethanol (4a,b), but in this case without optical selectivity. These results showed that biocatalytic reduction of ketones by immobilization hyphal of marine fungi depends on the xenobiotic substrate and the support matrix used. (c) 2012 Elsevier B.V. All rights reserved.
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The synthesis of chiral-centered selenium compounds is presented. Enantioselective oxidations of these organoselenium compounds were performed using a wide range of biocatalysts, including Baeyer-Villiger monooxygenases, oxidoreductases-containing Aspergillus terreus and lipase (Cal-B) in the presence of oxidants. Finally, efficient synthesis of enantiopure organoselenium compounds using a kinetic resolution approach mediated by Cal-B was achieved. (C) 2012 Elsevier Ltd. All rights reserved.
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We describe the genetic transformation of the mycelial tissue of Diaporthe phaseolorum, an endophytic fungus isolated from the mangrove species Laguncularia racemosa, using Agrobacterium tumefaciens-mediated transformation (ATMT). ATMT uses both the hygromycin B resistant (hph) gene and green fluorescent protein as the selection agents. The T-DNA integration into the fungal genome was assessed by both PCR and Southern blotting. All transformants examined were mitotically stable. An analysis of the T-DNA flanking sequences by thermal asymmetric interlaced PCR (TAIL-PCR) demonstrated that the disrupted genes in the transformants had similarities with conserved domains in proteins involved in antibiotic biosynthesis pathways. A library of 520 transformants was generated, and 31 of these transformants had no antibiotic activity against Staphylococcus aureus, an important human pathogen. The protocol described here, using ATMT in D. phaseolorum, will be useful for the identification and analysis of fungal genes controlling pathogenicity and antibiotic pathways. Moreover, this protocol may be used as a reference for other species in the Diaporthe genus. This is the first report to describe Agrobacterium-mediated transformation of D. phaseolorum as a tool for insertional mutagenesis.
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Fungal and mycotoxin contamination was investigated in field samples of nuts, shells and pods of the Brazil nut collected during different periods in Itacoatiara, State of Amazonas, Brazil: day 0, samples still on the tree: days 5, 10 and 15, samples in contact with soil for 5, 10 and 15 days, respectively. The most prevalent fungi were Aspergillus flavus in fruit pods and nuts and Fusarium spp. in shells. Penicillium spp. and A. flavus were isolated from soil, and Fusarium spp. and Penicillium spp. from air. Aflatoxins and cyclopiazonic acid were not detected in any of the samples analyzed. The high frequency of isolation of aflatoxigenic A. flavus strains from soil and Brazil nuts increases the chance of aflatoxin production in these substrates. These findings suggest a possible contamination before drying and indicate soil as the main source of fungal contamination of Brazil nuts. (c) 2012 Elsevier Ltd. All rights reserved.