S. Gravesen

Production of mycotoxins on artificially and naturally infested building materials

In this study, the ability to produce mycotoxins during growth on artificially infested building materials was investigated for Penicillium chrysogenum, Pen. polonicum, Pen. brevicompactum, Chaetomium spp., Aspergillus ustus, Asp. niger, Ulocladium spp., Alternaria spp., and Paecilomyces spp., all isolated from water-damaged building materials. Spores from the different isolates of the above mentioned species were inoculated on gypsum board with and without wallpaper and on chipboard with and without wallpaper. Fungal material was scraped off the materials, extracted, and analyzed using high performance liquid chromatography-diode array detection and thin layer chromatography. All six isolates of C. globosum produced the toxic chaetoglobosins A and C, at levels of up to 50 and 7 μg/cm2 respectively. The quantities of secondary metabolites produced by Penicillia were generally low, and no toxin production was detected from any of the five isolates of Pen. chrysogenum. Both isolates of Pen. polonicum produced 3-methoxy-viridicatin, verrucosidin, and verrucofortine. Two of five isolates of Pen. brevicompactum produced mycophenolic acid. From five out of six isolates of Alternaria spp., alternariol and alternariol monomethyl ether were detected. From Ulocladium spp., Paecilomyces spp., and Asp. ustus no known mycotoxins were detected, although the latter two are known mycotoxin producers. Asp. niger produced several naphtho-γ-pyrones and tetra-cyclic compounds. All investigated species, especially Asp. ustus and Asp. niger produced many unknown secondary metabolites on the building materials. Analyses of wallpaper and glass-fibre wallpaper naturally infested with Asp. versicolor revealed sterigmatocystin and 5-methoxysterigmatocystin. Analyses of naturally infested wallpaper showed that C. globosum produced the chaetoglobosins A and C, and Pen. chrysogenum produced the antibiotic meleagrin.

Production of mycotoxins on artificially inoculated building materials

Isolates of Stachybotrys chartarum, Aspergillus versicolor and Trichoderma spp. from water damaged Danish buildings were grown on old and new gypsum boards, wood pieces, chipboard, gypsum board with wallpaper and acoustic ceiling tiles. Production of sterigmatocystin and 5-methoxysterigmatocystin by each of 5 isolates of A. versicolor growing on pine wood, wallpaper, gypsum board and chipboard, were detected using HPLC with diode array detection and TLC with AlCl3 staining. After derivatization to the heptafluorobutyrlated ester and using gas chromatography ion trap mass spectrometry, negative ion chemical ionisation, for detection, trichothecenes of the verrucarol type were found in 4 of 5 isolates of S. chartarum growing on old and new gypsum boards. None of 8 Trichoderma isolates produced the trichothecenes T-2 toxin, HT-2 toxin, diacetoxyscirpenol, fusarenon-X, deoxynivalenol, nivalenol or trichothecenes of the verrucarol or trichodermol type on any of the above mentioned materials.

Volatile organic compounds from the indoor mould Trichoderma viride cause histamine release from human bronchoalveolar cells.

F. O. Larsen , P. Clementsen, M. Hansen, N. Maltbæk, T. Ostenfeldt-Larsen, K. F. Nielsen, S. Gravesen, P. Stahl Skov and S. Norn Department of Pharmacology, University of Copenhagen, The Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark, Fax +45 35 32 76 10 Department of Pulmonary Medicine, Gentofte Hospital, University of Copenhagen, Niels Andersens Vej 65, DK-2900 Hellerup, Denmark Department of Biotechnology, Technical University of Denmark, DK-2800 Lyngby, Denmark The Danish Building Research Institute, Dr. Neergaardsvej 15, DK-2970 Hørsholm, Denmark Reference Laboratory, Henrik Harpestrengs Vej 4, DK-2100 Copenhagen Ø, Denmark

The indoor microfungus Trichoderma viride potentiates histamine release from human bronchoalveolar cells

Trichoderma viride (Tv) is often found in damp and mouldy buildings where people complain of adverse health effects including mucosal/respiratory symptoms. Inhaled spores can reach the alveoli and may interact with the airway epithelium. An interaction with the mucosal mast cells was studied in cells obtained by bronchoalveolar lavage (BAL) from 18 individuals. The fungal spores were found to trigger histamine release from the BAL cells, but relatively high concentrations (0.1–2 mg/ml) were needed. A similar dose response was obtained in basophil histamine release. The Tv‐induced mediator release was caused by non‐immunological (non‐IgE‐dependent) mechanisms since the histamine release was not changed by removal of IgE from the basophils before exposure of the cells to the spores. However, in very low concentrations (0.1 ng/ml) the fungal spores were found to potentiate IgE‐mediated histamine release triggered by anti‐IgE antibody in suspensions of BAL cells. Potentiation was also obtained in basophil histamine release, but relatively high concentrations of Tv (10−2 mg/ml) were needed. Our in vitro experiments show that mucosal mast cells from the airways are highly sensitive to the potentiating effect of Tv. Although inhalation studies are needed to determine the in vivo effect of the spores, the results suggest reinforcement of mediator release to be a mechanism in the adverse health implications observed in mouldy buildings.

Microfungi in indoor air are able to trigger histamine release by non-IgE-mediated mechanisms

Staehybotrys atra (SA) (syn: S. chartarum) and other mierofungi are found in humid and poor quality indoor climates, and in humid hay and straw in farms. They are thought to be important eausative agents in organie, dustrelated diseases and the siek building syndrome [1, 2]. Allergie reaetions (Type land IU) and other meehanisms may be involved in these eonditions and histamine release is enhaneed by exposure to the mierofungi [3-6]. Sinee mediator release may be of key importanee in the development of obstruetive and infiammatory respiratory symptoms, we investigated whether histamine release ean be triggered direetly by mierofungi, i.e. by non-immunologieal meehanisms.

SICK BUILDING SYNDROME : ASSOCIATION OF SYMPTOMS WITH SERUM IGE SPECIFIC TO FUNGI

IntroductionSince the mid-eighties, reports of adverse health effects suchas sick building syndrome (SBS) in buildings with moistureand mould have been published [1–3]. However, until nowno studies have demonstrated a solid cause-relationshipbetween mould growth and sick building related symptoms.Using the histamine-release test (HRT) we previouslyexamined the staff of two municipal schools and of anindoor swimmingbath. We found IgE-specific to fungi fromthe buildings, both in serum and bound to basophils. Thestaff members reported SBS symptoms, but no history oftype I allergic disease [4]. In this study we have examinedwhether the presence in serum of IgE specific to fungi,verified by HRT, was associated with sick building relatedsymptoms.Materials and methods

Fungal spores enhance basophil histamine release

The effects of whole spores from moulds were examined concerning histamine release using leukocyte suspensions from normal (non-atopic) individuals and grass pollen-allergic patients. Spores fromChaetomium globosum, Mucor racemosus andAspergillus terreus caused no histamine release in concentrations up to 0.1 or 1 mg/ml, but they enhanced mediator release triggered by both IgE-dependent stimuli (grass-pollen allergen and anti-IgE antibody) and non-immunological stimuli (Staphylococcus aureus and calcium ionophore). Organic dust contains microfungi as well as bacteria and endotoxins. Earlier we have shown that bacteria release mediators from human lung cells and that bacteria and their endotoxins potentiate mediator release. It is now demonstrated that fungal spores also have potentiating ability. The content of all these microorganisms in dust may therefore be responsible for the symptoms observed after occupational exposure to organic dusts.

Microorganisms and mediator release: a mechanism in respiratory disorders caused by infectious and environmental exposure.

Bacter ia and microfungi are bel ieved to be o f pa thophys io logica l impor t ance in obs t ruct ive a i rway diseases and d isorders caused by env i ronmenta l exposure to mic roorgan i sms in dus t dur ing work in agr icul ture [1, 2]. W e therefore examined the effect o f these microorganisms on h is tamine release f rom h u m a n basophi l leukocytes and mas t cells ob ta ined by b ronchoa lveo l a r lavage (BAL).