Effects of aerosols from nontoxic Stachybotrys chartarum on murine airways

Acute effects on the upper and lower respiratory tract due to inhalation exposure to Stachybotrys chartarum (Sc) extract were investigated in mice. In addition, the capacity of the Sc exposure to activate immune system and cause inflammation in the respiratory tract was studied. The inhalation of Sc extract aerosols was observed to provoke sensory irritation in the airways of both naive and Sc-immunized mice. In contrast, exposure to aerosolized ovalbumin or phosphate buffered saline did not cause this effect. Exposure to Sc twice a week for 3 wk increased significantly the serum total immunoglobulin E (IgE) levels in BALB/c mice immunized with Sc as well as in nonimmunized mice. A slight presence of inflammatory cells was observed in the alveoli 3 days after the last exposure to Sc. In conclusion, Sc extract has the capacity to provoke sensory irritation in the murine airways and to activate the murine immune system.