Poster Presenter

Secondary Metabolites of Indoor Fungi Affecting Respiratory System
Elena Piecková, Marta Hurbánková, Zuzana Kováciková, Silvia Cerná, Erica Bloom*, Monika Mészárosová, Maja Šegvic-Klaric and Elisabeth Tátrai
Slovakia

Water damaged building materials are often contaminated with fungi that produce detectable levels of mycotoxins, and/or fungal volatiles that both increase the indoor air pollution. Respiratory toxicity of the most frequent indoor moulds - under Slovak dwellings´ conditions (Aspergillus versicolor, A. ustus, Penicillium expansum, P. chrysogenum) and top risky Stachybotrys chartarum – from public health point of view - with extrolites´ profiles (after cultivation on the liquid medium with 20 % sucrose and 2 % yeast extract, 14 d, 25 °C) characterized by TLC and LC/MS/MS and a bioassay employing Bacillus subtilis, was studied in vitro by analyses of histological and biochemical alterations of rat organs (lungs) or cell cultures (lung cells type II, Clara cells), and in vivo after the intratracheal instillation in wistar male rats (ca. 200 g) in 3-days experiments. Pure solvent (2 % dimethylsulphoxide – negative control) and standards of mycotoxins potentially produced by the fungi tested (sterigmatocystin, patulin, ochratoxin and diacetoxyscirpenol; 20 or 4 mg/ml ) were used. Cytotoxic (phagocytic activity and viability of alveolar macrophages - AM, the lactate dehydrogenase and acid phosphatase acitivities) and inflammatory response biomarkers (broncholaveolar lavage fluid – BALF cell counts, number of AM, granulocyte and AM differentials in BALF cell counts) were measured in the BALF. All fungal metabolites tested showed certain toxic effects that were concentration and cell origin of the toxicant (exo- or endometabolite) dependent. Generally, exometabolites (produced by fungi into their growth medium) were able to damage upper and lower airways and cause hematological disorders in rats in vitro, or in vivo respectively, much stronger. Lasting/repeated exposure to the indoor moulds and their metabolites may contribute to severe, even irreversible, health mutations in occupants of affected buildings.