BACTERIA, MOLDS, AND TOXINS IN WATER-DAMAGED BUILDING-MATERIALS

Microbial toxins and eukaryotic cell toxicity from indoor building mat erials heavily colonized by fungi and bacteria were analyzed. The domi nant colonizers at water-damaged sites of the building were Stachybotr ys chartarum (10(3) to 10(5) visible conidia cm(-2)), Penicillium and Aspergillus species (10(4) CFU mg(-1)), gram-negative bacteria (10(4) CFU mg(-1)), and mycobacteria (10(3) CFU mg(-1)). The mycobacterial is olates were most similar to M. komossense, with 98% similarity of the complete 16S rDNA sequence. Limulus assay of water extracts prepared f rom a water-damaged gypsum liner revealed high contents of gram-negati ve endotoxin (17 ng mg(-1) of E. coli lipopolysaccharide equivalents) and beta-D-glucan (210 ng mg(-1) of curdlan equivalents). High-perform ance liquid chromatography analysis of the methanol extracts showed th at the water-damaged gypsum liner also contained satratoxin (17 ng mg( -1)). This methanol-extracted substance was 200 times more toxic to ra bbit skin and fetus feline lung cells than extract of gypsum liner sam pled from a non-water-damaged site, The same extract contained toxin(s ) that paralyzed the motility of boar spermatozoa at extremely low con centrations; the 50% effective concentration was 0.3 mu g of dry solid s per ml. This toxicity was not explainable by the amount of bacterial endotoxin, beta-D-glucan, or satratoxin present in the same extract. The novel in vitro toxicity test that utilized boar spermatozoa as des cribed in this article is convenient to perform and reproducible and w as a useful tool for detecting toxins of microbial origin toward eukar yotic cells not detectable in building materials by the other methods.