Protein translation inhibition by Stachybotrys chartarum conidia with and without the mycotoxin containing polysaccharide matrix.

Recent studies have correlated the presence of Stachybotrys chartarum in structures with SBS. S. chartarum produces mycotoxins that are thought to produce some of the symptoms reported in sick-building syndrome (SBS). The conidia (spores) produced by Stachybotrys species are not commonly found in the air of buildings that have been found to contain significant interior growth of this organism. This could be due in part to the large size of the Stachybotrys spores, or the organism growing in hidden areas such as wall cavities. However, individuals in buildings with significant Stachybotrys growth frequently display symptoms that may be attributed to exposure to the organism's mycotoxins. In addition, Stachybotrys colonies produce a "slime" or polysaccharide (carbohydrate) matrix that coats the hyphae and the spores. The intent of this project was to determine whether the carbohydrate matrix and the mycotoxins embedded in it could be removed from the spores by repeated washings with either aqueous or organic solvents. The results demonstrated that the process of spore washing removed compounds that were toxic in a protein translation assay as compared to spores that were washed with an organic solution, however a correlation between carbohydrate removal during the washing process and the removal of mycotoxins from the spore surface was not observed. These data demonstrated that mycotoxins are not likely to be found exclusively in the carbohydrate matrix of the spores. Therefore, mycotoxin removal from the spore surface can occur without significant loss of polysaccharide. We also showed that toxic substances may be removed from the spore surface with an aqueous solution. These results suggest that satratoxins are soluble in aqueous solutions without being bound to water-soluble moieties, such as the carbohydrate slime matrix.

Characterization of exposure to low levels of viable Penicillium chrysogenum conidia and allergic sensitization induced by a protease allergen extract from viable P. Chrysogenum conidia in mice.

BACKGROUND: Previous evidence by our laboratory has shown that mice inoculated with viable Penicillium Chrysogenum conidia or spores at levels comparable to those found in contaminated buildings induced spore antigen-specific allergic responses. We proposed that mice exposed to low levels of viable P. Chrysogenum conidia would not develop allergic symptoms. We also hypothesized that the symptoms induced by high numbers of conidia were the result of sensitization to allergens released by the conidia. METHODS: C57BL/6 and BALB/c mice were exposed to 1 x 10(2) viable P. Chrysogenum conidia by intranasal instillation weekly for a period of 11 weeks. C57BL/6 mice were also sensitized to a viable P. Chrysogenum conidia protease extract by intraperitoneal injections for a period of 6 weeks followed by intranasal challenge with protease extract, viable, or nonviable P. Chrysogenum conidia for 2 weeks. RESULTS: C57BL/6 mice inoculated with low numbers of conidia developed no significant lung inflammation or increased serum immunoglobulins. Mice sensitized to the protease extract and challenged with both protease extract and viable conidia produced significant increases in serum IgE and IgG1. Mice sensitized to and challenged with the protease extract developed significant eosinophilia and mucus hyperproduction as determined by bronchoalveolar lavage and histopathological examination of lung tissue. CONCLUSIONS: Mice did not develop allergic symptoms in response to challenge with low levels of P. Chrysogenum conidia. Protease allergens from viable conidia induced specific allergic responses in mice, indicating the importance of P. Chrysogenum conidia in allergic sensitization to the organism.

Studies on the role of fungi in Sick Building Syndrome.

Sick Building Syndrome is a term used to describe symptoms in humans which result from problems with indoor air quality. Common complaints include dyspnea, flu-like symptoms, watering eyes, and allergic rhinitis. Although there is likely no single cause for Sick Building Syndrome, fungal contamination in buildings has increasingly been associated with this spectrum of symptoms. The authors describe 2 case studies, and other experimentation, that have investigated the role of fungi in the occurrence of Sick Building Syndrome.