195 resultados para dimorphic pathogenic fungi


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Brazilian soils predominantly consist of iron and aluminum oxides and have a low phosphorus content. The present study was carried out in order to assess the status of phosphate fractions in pasture, forest and agricultural soils and the ability of soil fungi to solubilize iron and aluminum phosphates. The abundance of P fractions in the soils studied occurred in the following order: Fe-P > reductant-soluble Fe-P > occluded Fe-P > occluded Al-P > Al-P > Ca-P. of the 481 fungi isolated, 33 showed the ability to solubilize the inorganic phosphates in culture. of these, 14 were considered to be high or very high solubilizers based on a solubilization capacity > 1000 mu g PO43- ml(-1). Isolate F-111 was the only one that dissolved all the insoluble phosphates used. Nine isolates solubilized both Al-P and Ca-P, and four other isolates only solubilized Ca-P. The highest number of isolates with high solubilization capacity were detected in pasture soil, followed by tropical rain forest and forest patch soils. Pasture soil presented both the largest contents of insoluble phosphates and the largest number of fungal isolates with phosphate-solubilizing ability. The range and size of P fractions influenced the number of fungi and their ability to solubilize hardly soluble phosphates. (c) 2004 Elsevier B.V. All rights reserved.

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The effect of inoculation of Aspergillus flavus, Fusarium verticillioides, and Penicillium sp. in Dystrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL) soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucose in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides. The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides. The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times (p <0.05) in soils with glucose and inoculated with the fungi (except F. verticillioides), in relation to soil without glucose. Amylase activity increased 1.3 to 1.5 times due to the addition of glucose in the soil. Increased amylase activity was observed in the DRL soil with glucose and inoculated with A. flavus and Penicillium sp. when compared to control.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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As formigas cortadeiras atacam diversas culturas agrícolas, pastagens e os reflorestamentos, atuando sobre muitas espécies vegetais. O presente trabalho teve por objetivo avaliar a patogenicidade dos fungos Beauveria bassiana (isolados AM 9 e JAB 06), Metarhizium anisopliae (isolados E 9 e AL) e Paecilomyces farinosus (isolados CG 189 e CG 195) a soldados de Atta sexdens sexdens, em condições de laboratório. Após a coleta em formigueiro isento de produtos fitossanitários, exemplares de soldados foram cuidadosamente separados em grupos de oito indivíduos e, a seguir, banhados em suspensões contendo 1,0 x 10(6), 1,0 x 10(7), 1,0 x 10(8) e 1,0 x 10(9) conídios/mL de cada isolado. em seguida, cada grupo de formigas foi transferido para unidades de câmara úmida e mantido, sem alimentação, a 27 ± 1 ºC. A mortalidade foi verificada diariamente. Os três fungos se mostraram eficientes patógenos, pois provocaram alta mortalidade, matando mais que 80% dos soldados nos quatro primeiros dias após a inoculação. Os melhores isolados foram JAB 06 e AL, na concentração de 1,0 x 10(9) con./mL. Os isolados JAB 06, AL, CG 195 apresentaram maior capacidade de esporular nos cadáveres das formigas e os tempos letais decresceram com o aumento da concentração de conídios usada.

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Cornitermes cumulans is a termite species often found in pastures of Brazil, mainly in the most degraded ones. Chemical control has been the most recommended method against this insect pest, but control measures are usually avoided by farmers. Biocontrol of termites with entomopathogenic fungi and possibly with entomopathogenic nematodes have been considered promising techniques, being recommended for use in several countries. This study aimed to evaluate the pathogenicity of Steinernema carpocapsae (an unidentified isolate) against C cumulans castes (workers and soldiers). Three experiments were done, one using Petri dishes, with daily evaluations, and two others in artificial colonies (with workers and soldiers). For one of the experiments in artificial colonies, nematode suspensions (167 and 333 infective juveniles (IJ) per insect) were applied over the food supplied to the termites. For the other experiment, nematode suspensions (133, 267 and 533 IJ per insect) were applied directly over the artificial termite colonies. In these two experiments evaluations were done 1, 5 and 9 days after nematode application. Each dead insect was dissected for nematode verification. S. carpocapsae was highly pathogenic to both castes of C cumulans in all experiments.

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A preservação de fungos fitopatogênicos por longos períodos de tempo é importante para que pesquisas possam ser realizadas a qualquer momento. Os fungos habitantes do solo são organismos que podem produzir estruturas de resistência em face de situações adversas, tais como ausência de hospedeiros e ou condições climáticas desfavoráveis para a sua sobrevivência. O objetivo deste trabalho foi desenvolver metodologias de preservação de estruturas de resistência para os fungos Fusarium oxysporum f.sp. lycopersici raça 2, Macrophomina phaseolina, Rhizoctonia solani AG4 HGI, Sclerotium rolfsii, Sclerotinia sclerotiorum e Verticillium dahliae. O delineamento foi inteiramente casualizado, com um método de produção de estruturas para cada fungo, submetido a três tratamentos [temperatura ambiente de laboratório (28±2ºC), de geladeira (5ºC) e de freezer (-20ºC)] e com dois frascos por temperatura. Mensalmente, e por um período de um ano, a sobrevivência e o vigor das colônias de cada patógeno foram avaliadas em meios de cultura específicos. Testes de patogenicidade foram realizados após um ano de preservação, com as estruturas que sobreviveram aos melhores tratamentos (temperatura) para todos os fungos. As melhores temperaturas (tratamentos) para preservar os fungos foram: a) F. oxysporum f.sp. lycopersici em temperatura de refrigeração e de freezer (5,2 e 2,9 x 10³ufc.g-1 de talco, respectivamente); b) M. phaseolina em temperatura de refrigeração [100% de sobrevivência (S) e índice 3 de vigor (V)] e S. rolfsii em temperatura ambiente (74,4% S e 1 V) e c) S. sclerotiorum e V. dahliae, ambos em temperatura de freezer (100% S e 3 V). Após um ano de preservação, somente V. dahliae perdeu a patogenicidade na metodologia desenvolvida.

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Objectives To evaluate the presence of fungi on contact electrodes and ultrasound transducers from physiotherapy clinics.Design Quantitative study conducted at the Laboratory of Microbiology and Immunology, Faculty of Health Sciences and Technology of Piaui - NOVAFAPI, Teresina, Brazil.Setting Sample collection was performed in 10 clinics ( 20 ultrasound transducers and 20 contact electrodes).Main outcome measures Swabs were soaked with saline solution, inoculated in culture and incubated for filamentous fungi and yeast growth.Results Fourteen taxons were identified: Acremomium hyalinulum (Sacc.), Aspergillus terreus, Candida albicans, Cladosporium cladosporioides, Cladosporium elatum, Cladosporium oxysporum, Cladosporium sphaerospermum, Cladosphialophora bantiana, Curvularia clavata, Curvularia senegalensis, Fusarium oxysporum, Penicillium decumbens, Scopulariopsis candida and Sporothrix schenckii. Aspergillus terreus, Cladosporium oxysporum, Sporothrix shenckii and Candida albicans were found most often on contact electrodes, and Penicillium decumbens and Cladosporium cladosporioides were found most often on ultrasound transducers.Conclusion Fungi were found on all of the contact electrodes and ultrasound transducers. Physiotherapy professionals need to improve the disinfection procedures for this equipment. (C) 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

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Aims: The aim of this study was to identify and determine the diversity, occurrence and distribution of fungi in water used at a haemodialysis centre.Methods and Results: Samples in the hydraulic circuit for the distribution of the water, dialysate samples and samples of sterilization solution from dialysers were collected over a 3-month period, and 500 ml of each sample was filtered through membranes. All together 116 isolates of fungi were recovered from 89% of all water samples collected inside the haemodialysis unit, with prevalence of moulds in tap water samples and of yeasts in dialysate samples. Fusarium spp. was the most abundant genus found, whereas Candida parapsilosis was the predominant yeast species.Conclusions: This study demonstrated that various fungi were present in the water system. These data suggest the inclusion of the detection and quantification of fungi in the water of haemodialysis.Significance and Impact of the Study: The recovery of fungi from aqueous haemodialysis environments implies a potential risk for haemodialysis patients and indicates the need for continuous maintenance and monitoring. Further studies on fungi in haemodialysis water systems are required to investigate the organism ability to persist, their role in biofilm formation and their clinical significance.

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Although the main reservoir of Candida spp. is believed to be the buccal mucosa, these microorganisms can coaggregate with bacteria in subgingival biofilm and adhere to epithelial cells. The treatment of periodontal disease includes scaling and root planning (SR?) associated with proper oral hygiene. However, some patients may have negative responses to different therapeutic procedures, with a continuous loss of insertion, so the use of antimicrobials is needed as an adjuvant to SRP treatment. The use of a broad-spectrum antibiotic, such as tetracycline and metronidazole, as an aid in periodontal treatment has also been a factor for the development of superinfections by resistant bacteria and Candida species, even in patients with HIV. In the dental practice, the most commonly used antifungals are nystatin and fluconazole. However, the introduction of new drugs like the next generation of azoles is essential before the onset of emergent species in periodontal disease. Plants are good options for obtaining a wide variety of drugs. This alternative could benefit a large population that uses plants as a first treatment option. Plants have been used in medicine for a long time and are extensively used in folk medicine, because they represent an economic alternative, are easily accessible and are applicable to various diseases. Herein, we briefly review the literature pertaining the presence of Candida sp. in periodontal pockets, the conventional antifungal resistance and new therapies that include natural antifungal agents are reviewed. (C) 2011 Elsevier Ltd. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)