The ABC transporter gene in the sirodesmin biosynthetic gene cluster of Leptosphaeria maculans is not essential for sirodesmin production but facilitates self-protection

Epipolythiodioxopiperazine toxins are secreted by a range of fungi, including Leptosphaeria maculans, which produces sirodesmin, and Aspergillus fumigatus, which produces gliotoxin. The L. maculans biosynthetic gene cluster for sirodesmin includes an ABC transporter gene, sirA. Disruption of this gene led to increased secretion of sirodesmin into the medium and an altered ratio of sirodesmin to its immediate precursor. The transcription pattern of a peptide synthetase that catalyses an early step in sirodesmin biosynthesis was elevated in the sirA mutant by 47% over a 7-day period. This was consistent with the finding that the transporter mutant had elevated sirodesmin levels. Despite increased production of sirodesmin, the sit-A mutant was more sensitive to both sirodesmin and gliotoxin. The putative gliotoxin transporter gene, gliA, (a major facilitator superfamily transporter) from A.fumigatus complemented the tolerance of the L. maculans sirA mutant to gliotoxin, but not to sirodesmin. The results indicate that SirA contributes to self-protection against sirodesmin in L. maculans and suggest a transporter other than SirA is primarily responsible for efflux of endogenously produced sirodesmin. (C) 2004 Elsevier Inc. All rights reserved.

Oral candidosis and the therapeutic use of antifungal agents in dentistry

This paper reviews the current concepts of mycology and candidal infections as they relate to the oral cavity. Proposed classification for the presentation of oral candidosis is outlined as are examples of these topical infections, such as erythematous, pseudomembranous and hyperplastic candidosis, as well as angular chelitis and median rhomboid glossitis. The diagnosis and principles of management of oral candidosis are discussed, the therapeutic agents available for the management of these infections are presented and a treatment protocol for the management of patients with oral candidosis is given.

CandiVF - Candida albicans virulence factor database

Candida albicans is a pathogen commonly infecting patients who receive immunosuppressive drug therapy, long-term catheterization, or those who suffer from acquired immune deficiency syndrome (AIDS). The major factor accountable for pathogenicity of C. albicans is host immune status. Various virulence molecules, or factors, of are also responsible for the disease progression. Virulence proteins are published in public databases but they normally lack detailed functional annotations. We have developed CandiVF, a specialized database of C. albicans virulence factors (http://antigen.i2r.a-star.edu.sg/Templar/DB/CandiVF/) to facilitate efficient extraction and analysis of data aimed to assist research on immune responses, pathogenesis, prevention, and control of candidiasis. CandiVF contains a large number of annotated virulence proteins, including secretory, cell wall-associated, membrane, cytoplasmic, and nuclear proteins. This database has in-built bioinformatics tools including keyword and BLAST search, visualization of 3D-structures, HLA-DR epitope prediction, virulence descriptors, and virulence factors ontology.

Identification and characterization of non-pathogenic Fusarium oxysporum capable of increasing and decreasing Fusarium wilt severity

Fusarium wilt of banana is a potentially devastating disease throughout the world. Options for control of the causal organism, Fusarium oxysporum f.sp. cubense (Foc) are limited. Suppressive soil sites have previously been identified where, despite the presence of Foc, Fusarium wilt does not develop. In order to understand some aspects of this disease suppression, endophytic Fusarium oxysporum isolates were obtained from banana roots. These isolates were genetically characterized and compared with an isolate of Fusarium oxysporum previously identified as being capable of suppressing Fusarium wilt of banana in glasshouse trials. Three additional isolates were selected for glasshouse trials to assess suppression of Fusarium wilt in two different cultivars of banana, Cavendish and Lady Finger. One isolate (BRIP 29089) was identified as a potential biocontrol organism, reducing the disease severity of Fusarium wilt in Lady Finger and Cavendish cultivars. Interestingly, one isolate (BRIP 45952) increased Fusarium wilt disease severity on Cavendish. The implications of an isolate of Fusarium oxysporum, non-pathogenic on banana, increasing disease severity and the potential role of non-pathogenic isolates of Fusarium oxysporum in disease complexes are discussed. (c) 2006 Published by Elsevier Ltd on behalf of The British Mycological Society.

Notes on the type, synonyms, and other specimens of the balansioid fungus, Nigrocornus scleroticus

The type, and other specimens of the balansioid fungus, Nigrocornus scleroticus, its synonyms, and similar fungi studied during extensive research on the taxonomy and biology of the fungus, are described. Two hypocrealean fungi found parasitising the ascostromata of N. scleroticus are also discussed.

Homothallism in Sclerotinia minor

Sclerotinia species are sexually reproducing ascomycetes. In the past S. minor and S. sclerotiorum, have been assumed to be homothallic because of the self-fertility of colonies derived from single ascospores. S. trifoliorum has previously been shown to be bipolar heterothallic due to the presence of four self-fertile and four self-sterile ascospores within a single ascus [Uhm, J.Y., Fujii, H., 1983a. Ascospore dimorphism in Sclerotinia trifoliorum and cultural characters of strains from different-sized spores. Phytopathology 73: 565-569]. However, isolates of S. minor and S. sclerotiorum were proven to be homothallic ascomycetes, by self-fertility of all eight ascospores within an ascus. Apothecia were raised from all eight ascospores of a single tetrad from four isolates of S. minor and from an isolate of S. sclerotiorum, indicating that inbreeding may be the predominant breeding mechanism of S. minor. Ascospores from asci of S. minor and S. sclerotiorum were predominantly monomorphic, but rare examples of ascospore dimorphism similar to S. trifoliorum were found. (c) 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

The importance of subclasses of chitin synthase enzymes with myosin-like domains for the fitness of fungi

TG and CF are funded by FEDER funds through the Operational Programme Competitiveness Factors e COMPETE and national funds by FCT e Foundation for Science and Technology under the strategic project UID/NEU/04539/2013. C.F. is a recipient of a postdoctoral fellowship from FCT-Fundac¸ ~ao para a Ci^encia e Tecnologia (SFRH/BPD/63733/2009). NG is funded by The Wellcome Trust (080088, 086827, 075470, 099215 & 097377), the FungiBrain Marie Curie Network and the Medical Research Council (UK).

International expert opinion on the management of infection caused by azole-resistant Aspergillus fumigatus

Acknowledgements We thank Gilead Sciences Europe Ltd., UK for financially supporting logistical aspects of this study. The logistics of the meeting were handled by Congress Care, Den Bosch, The Netherlands. The sponsor was not involved in the selection of the participants or procedures, or in the discussion, data collection, analysis or writing of the manuscript. The medical writer was financially supported by the Dutch Society for Medical Mycology and the Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands.

Analysis of surfaces for characterization of fungal burden: does it matter?

Objectives: Mycological contamination of occupational environments can be a result of fungal spores’ dispersion in the air and on surfaces. Therefore, it is very important to assess it in both types of the samples. In the present study we assessed fungal contamination in the air and in the surface samples to show relevance of surfaces sampling in complementing the results obtained in the air samples. Material and Methods: In total, 42 settings were assessed by the analysis of air and surfaces samples. The settings were divided into settings with a high fungal load (7 poultry farms and 7 pig farms, 3 cork industries, 3 waste management plants, 2 wastewater treatment plants and 1 horse stable) and a low fungal load (10 hospital canteens, 8 college canteens and 1 maternity hospital). In addition to culture-based methods, molecular tools were also applied to detect fungal burden in the settings with a higher fungal load. Results: From the 218 sampling sites, 140 (64.2%) presented different species in the examined surfaces when compared with the species identified in the air. A positive association in the high fungal load settings was found between the presence of different species in the air and surfaces. Wastewater treatment plants constituted the setting with the highest number of different species between the air and surface. Conclusions: We observed that surfaces sampling and application of molecular tools showed the same efficacy of species detection in high fungal load settings, corroborating the fact that surface sampling is crucial for a correct and complete analysis of occupational scenarios.

Occupational exposure to Aspergillus spp. in poultry and swine feed production

Workers from feed production often develop allergic respiratory symptoms and fungi are likely to be a significant contributing factor to these symptoms. This study intended to characterize fungal contamination in two feed production units, one for poultry and other for swine consumption. We aimed at identifying which unit presented the highest risk of occupational exposure to Aspergillus spp.

Professional exposure to fungal pathogens: an update to exposure conditions and exposure measurement

In many occupational settings an exposure to fungi occurs. Fungal exposure may occur for instance in the form of dermatocytes, yeasts or mold. Associated to the fungi themselves an exposure to cell wall components like ß(1 ? 3)-D-glucans, to mycotoxins or to microbial volatile compounds can occur. Health hazards may differ across species because fungi may produce different allergens and mycotoxins, and some species can infect humans. Occupational settings are often characterized by special exposure conditions with respect to duration, frequency and especially to the level of exposure resulting at least sometimes to high or very high fungal exposure. Because of these special conditions occupational settings are suitable for epidemiologic studies. However, the knowledge about occupational exposure to fungi and associated compounds like mycotoxins is still fragmentary and not well disseminated. An indication for a high fungal exposure is for instance the handling of dry natural products like grain, hay or herbal plants with a high specific surface and the tendency to release dust during handling. The fungal components often form the determinative part of such dusts and might be a vehicle to respiratory airways. The authors will present results of exposure measurements of occupational settings and exposure conditions which are only rarely investigated.

Fungal contamination in one hotel room: does carpet coating in the floor enhance fungal contamination?

Interest in bioaerosol exposure has increased significantly because it is now recognized that exposure to fungal agents is associated with a wide range of adverse health effects with a major impact on public health. Fungi are able to grow on almost all natural and synthetic materials, especially if they are hygroscopic or wet. Aim of the study: Several materials used indoors can contribute to enhance fungal contamination indoors. This study intended to understand the carpet influence on fungal contamination when used in the floor of a hotel room.

Accessing occupational exposure to fungi in a cork industry

Different forms of fungal diseases affecting the nose and paranasal sinuses are recognized, including invasive and non-invasive fungal rhinosinusitis. Penicillium glabrum complex is associated with respiratory diseases such as suberosis, a typical disease of cork industry workers. In addition, Chrysonilia sitophila has been described as causing occupational asthma, associated to prolonged exposure to high counts of spores. In this study we aimed to access fungal exposure in workers from one cork industry through the mycological analysis of their nasal exudate and the environmental fungal contamination of their surroundings as well.

Scedo-Select III: a new semi-selective culture medium for detection of the Scedosporium apiospermum species complex

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A record of the fungi named by J. B. Ellis.

Mode of access: Internet.