The status of soil phosphate fractions and the ability of fungi to dissolve hardly soluble phosphates

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.

Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil

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.

Filamentous fungi found on foundress queens of leaf-cutting ants (Hymenoptera: Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Selection of fungi for accelerated decay in stumps of Eucalyptus spp.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Application technology for the entomopathogenic nematodes Heterorhabditis indica and Steinernema sp. (Rhabditida: Heterorhabditidae and Steinernematidae) to control Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in corn

O efeito de diversas tecnologias de aplicação foi avaliado sobre a concentração, viabilidade e eficácia dos juvenis infectantes dos nematóides Heterorhabditis indica Poinar, Karunakar & David (IBCB-n5) e Steinernema sp. (IBCB-n6) no controle da lagarta-do-cartucho Spodoptera frugiperda Smith na cultura do milho. Para o controle da lagarta-do-cartucho no terceiro estádio em placas de Petri foram necessários 280 juvenis infectantes de Steinernema sp., enquanto que 400 juvenis infectantes de H. indica controlaram apenas 75% das lagartas. Podem-se pulverizar os entomopatógenos, sem que haja perda significativa na sua concentração e viabilidade, com equipamentos que forneçam carga elétrica à calda, ponta centrífuga e pontas hidráulicas. Entretanto, o emprego de pulverizadores com pontas que requerem elementos filtrantes com malha igual a 100 resultou em decréscimo na concentração de juvenis infectantes de H. indica e Steinernema sp., de 28% e 53%, respectivamente. Os tensoativos organosiliconado e etoxilados não afetaram a viabilidade dos juvenis infectantes de Steinernema sp. Nos experimentos de pulverização em plantas de milho (V6) com Steinernema sp., doses equivalentes a até 288 milhões de juvenis infectantes por hectare, diluídos em volume de calda de até 800 L ha-1 com 0,01 % do tensoativo etoxilado, ou nesse volume seguido de exposição a chuva artificial (lâmina de água de 6 mm), não foram suficientes para o controle de S. frugiperda em casa-de-vegetação.

The presence of fungi on contact electrical stimulation electrodes and ultrasound transducers in physiotherapy clinics

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.

Occurrence of fungi in water used at a haemodialysis centre

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.

New antimicrobial therapies used against fungi present in subgingival sites-A brief review

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.

PTEN Directly Activates the Actin Depolymerization Factor Cofilin-1 During PGE(2)-Mediated Inhibition of Phagocytosis of Fungi

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

Pathogenesis II: Fungal responses to host responses: interaction of host cells with fungi

Most of our knowledge concerning the virulence determinants of pathogenic fungi comes from the infected host, mainly from animal models and more recently from in vitro studies with cell cultures. The fungi usually present intra- and/or extracellular host-parasite interfaces, with the parasitism phenomenon dependent on complementary surface molecules. Among living organisms, this has been characterized as a cohabitation event, where the fungus is able to recognize specific host tissues acting as an attractant, creating stable conditions for its survival. Several fungi pathogenic for humans and animals have evolved special strategies to deliver elements to their cellular targets that may be relevant to their pathogenicity. Most of these pathogens express surface factors that mediate binding to host cells either directly or indirectly, in the latter case binding to host adhesion components such as extracellular matrix (ECM) proteins, which act as 'interlinking' molecules. The entry of the pathogen into the host cell is initiated by fungal adherence to the cell surface, which generates an uptake signal that may induce its cytoplasmic internalization. Once this is accomplished, some fungi are able to alter the host cytoskeletal architecture, as manifested by a rearrangement of microtubule and microfilament proteins, and this can also induce epithelial host cells to become apoptotic. It is possible that fungal pathogens induce modulation of different host cell pathways in order to evade host defences and to foster their own proliferation. For a number of pathogens, the ability to bind ECM glycoproteins, the capability of internalization and the induction of apoptosis are considered important factors in virulence. Furthermore, specific recognition between fungal parasites and their host cell targets may be mediated by the interaction of carbohydrate-binding proteins, e.g., lectins on the surface of one type of cell, probably a parasite, that combine with complementary sugars on the surface of host-cell. These interactions supply precise models to study putative adhesins and receptor-containing molecules in the context of the fungus-host interface. The recognition of the host molecules by fungi such as Aspergillus fumigatus, Paracoccidioides brasiliensis and Histoplasma capsulatum, and their molecular mechanisms of adhesion and invasion, are reviewed in this paper.

Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Clues to the presence of pathogenic fungi in certain environments

The presence of various pathogenic fungi in rather unsuspected hosts and environments has always attracted the attention of the scientific community. Reports on the putative role of animals in fungal infections of humans bear important consequences on public health as well as on the understanding of fungal ecology. Fungi are ubiquitous in nature and their great capacity for adaptation allows them to survive and indeed, to thrive, in plants, trees and other natural substrata. Nonetheless, we are just beginning to learn the significance that these diverse fungal habitats have on the increasing number of immunosuppressed individuals. The accidental or permanent presence of fungi in animals, plants, soils and watercourses should not be taken too lightly because they constitute the source where potential pathogens will be contracted. If those fungal habitats that carry the largest risks of exposure could be defined, if seasonal variations in the production of infectious propagules could be determined, and if their mode of transmission were to be assessed, it would be possible to develop protective measures in order to avoid human infection. Additionally, unsuspected avenues for the exploration of fungal survival strategies would be opened, thus enhancing our capacity to react properly to their advancing limits. This paper explores several ecological connections between human pathogenic fungi and certain animals, trees, waterways and degraded organic materials. The occurrence of such connections in highly endemic areas will hopefully furnish more precise clues to fungal habitats and allow the design of control programs aimed at avoiding human infection.

Inteins in pathogenic fungi: a phylogenetic tool and perspectives for therapeutic applications

Inteins or internal proteins are coding sequences that are transcribed and translated with flanking sequences (exteins). After translation, the inteins are excised by an autocatalytic process and the host protein assumes its normal conformation and develops its expected function. These parasitic genetic elements have been found in important, conserved proteins in all three domains of life. Most of the eukaryotic inteins are present in the fungi kingdom and the PRP8 intein is one of the most widespread inteins, occurring in important pathogens such as Cryptococcus neoformans (varieties grubii and neoformans), Cryptococcus gattii, Histoplasma capsulatum and Paracoccidioides brasiliensis. The knowledge of conserved and non-conserved domains in inteins have opened up new opportunities for the study of population variability in pathogenic fungi, including their phylogenetic relationships and recognition or diagnoses of species. Furthermore, inteins in pathogenic fungi should also be considered a promising therapeutic drug target, since once the autocatalytic splicing is inhibited, the host protein, which is typically vital, will not be able to perform its normal function and the fungal cell will not survive or reproduce.

First evidence of an intimate symbiotic association between fungi and larvae in basal attine ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Yeasts and filamentous fungi carried by the gynes of leaf-cutting ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)