Co-occurrence of toxic bacterial and fungal secondary metabolites in moisture-damaged indoor environments

Abstract

Toxic microbial secondary metabolites have been proposed to be related to adverse health effects observed in moisture-damaged buildings. Initial steps in assessing the actual risk include the characterization of the exposure. In our study, we applied a multi-analyte tandem mass spectrometry-based methodology on sample materials of severely moisture-damaged homes, aiming to qualitatively and quantitatively describe the variety of microbial metabolites occurring in building materials and different dust sample types. From 69 indoor samples, all were positive for at least one of the 186 analytes targeted and as many as 33 different microbial metabolites were found. For the first time, the presence of toxic bacterial metabolites and their co-occurrence with mycotoxins were shown for indoor samples. The bacterial compounds monactin, nonactin, staurosporin and valinomycin were exclusively detected in building materials from moist structures, while chloramphenicol was particularly prevalent in house dusts, including settled airborne dust. These bacterial metabolites are highly bioactive compounds produced by Streptomyces spp., a group of microbes that is considered a moisture damage indicator in indoor environments. We show that toxic bacterial metabolites need to be considered as being part of very complex and diverse microbial exposures in moldy buildings. M. Tubel1, M. Sulyok2, V. Vishwanath2, E. Bloom3, M.Turunen1,K.Jrvi1,E.Kauhanen1, R. Krska2, A. Hyvrinen1, L. Larsson4, A. Nevalainen1 1Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland, 2Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna, Austria, 3Swedish Environmental Research Institute Ltd, Stockholm, Sweden, 4Department for Laboratory Medicine, Lund University, Lund, Sweden

Key Biomarkers

Symptom Clusters