Letters to the Editor

Abstract

This correspondence is in response to a paper recently published in the Journal of Applied Toxicology titled 'Mycotoxin identification in moldy dwellings' (Charpin-Kadouch et al., 2006). The authors claim their work is 'the first time direct evidence for the presence of macrocyclic trichothecenes (MCT) in moldy dwellings'. This simply is not the case. Our previous findings demonstrated the presence of MCT in the air of Stachybotrys chartarum-contaminated buildings (Brasel et al., 2005). In addition, our work has shown that these mycotoxins can be detected in the sera from persons exposed to S. chartarum within the indoor environment (Brasel et al., 2004). These results were published prior to the submission of the aforementioned manuscript (Charpin-Kadouch et al., 2006).The authors state that flooded houses were selected in their study based on the presence of S. chartarum or Chaetomium species. Both of these fungi require substrates with a water activity of >0.9 for optimal growth (Nielsen, 2003) and therefore, it would not be surprising for these organisms to be isolated together on water-saturated building materials. Chaetomium species are known to produce mycotoxins including chaetoglobosins, chaetomins, sterigmatocystins and chaetoviridins (Nielsen, 2003;Park et al., 2005); however, these species are not known producers of trichothecenes. Thus, the inclusion of houses with Chaetomium species is illogical if the objective is to detect MCT. This fact may also provide another explanation for 'the marked heterogeneity of MCT measurements' as well as the lack of correlation between moldy surface and MCT levels.The authors also state that the ELISA kit (QuantiTox Kit, EnviroLogix, Portland, Maine) used for detecting MCT contains monoclonal antibodies. This assay incorporates the use of rabbit polyclonal antibodies for MCT quantitation (Chung et al., 2003). Similar to the authors' results, we also detected MCT in control houses (Brasel et al., 2005). We hypothesized that these findings represent non-specific binding.