Microscopic filamentous fungi in the indoor environment represent serious health risk (allergies, acute and chronic respiratory tract illnesses etc.) for people living in affected buildings. The ascomycetous potentially toxic genus Chaetomium is the third most frequently isolated indoor contaminat. The aim of our work was an in vitro study of ciliostatic activity of endo- and exometabolites of 14 Chaetomium sp., including 4 Ch. globosum strains isolated from walls’ scrapes, and 3 Ch. globosum strains from the CCM collection. The endometabolites of 10 isolates of Chaetomium sp. were active ciliostatically: 7 isolates (41.2 % of total strains’ number) stopped tracheal cilia movement of 1-d-old chickens after 24 h, 9 isolates (52.9 %) after 48 h and 10 strains (58.8 %) after 72 h. In the case of exometabolites, the extracts of 6 species of chaetomia showed some ciliostatic activity: 2 isolates (11.8 % of strains tested) after 24 h, 5 isolates (29.4 %) after 48 h and 6 isolates (35.3 %) after 72 h. Chaetomium sp. as indoor fungi can contribute to ill health of occupants of mouldy damp flats.

        Key words: indoor evnironment - Chaetomium - ciliostatic activity