Characterizing Microbial Exposure With Ergosterol, 3-Hydroxy Fatty Acids, and Viable Microbes in House Dust: Determinants and Association With Childhood Asthma

Abstract

The authors assessed determinants of ergosterol, 3-OH fatty acids (FAs), and viable microbes in vacuum cleaner dust, and investigated the association between these microbial markers and childhood asthma. The authors studied the homes of 36 children who were new cases of childhood asthma and the homes of 36 controls. Home characteristics explained 34% to 44% of the variation in levels of different microbial groups. Determinants of 3-OH FAs were a lower level of cleanliness, having a fireplace, having livestock, and moisture damage; determinants of viable bacteria were the level of home repair needed and the material used in the building frame of the home. Ergosterol was associated with the presence of livestock and the practice of cleaning rugs outside; viable fungi was associated with the material used in the building frame, visible mold, and the practice of cleaning rugs outside. Exposure to mesophilic actinomycetes was nonsignificantly associated with risk of asthma. The authors concluded that the variation of microbial levels in dust could be explained relatively well by home characteristics, and suggested that exposure to mesophilic actinomycetes may increase the risk of new asthma.

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

“…The herein described sample material includes building materials and different dust sample types from the first nine homes that were recruited to the HoTeS study, collected before renovations. Floor dust was typically sampled in the living room, using a regular vacuum cleaner device and nylon dust sampling socks, as described by Hyva¨rinen et al (2006). Settled airborne dust samples were collected in the same way, but from surfaces above floor level, such as bookshelves and similar.…”

Dampness and Mold in the Indoor Environment: Implications for Asthma

“…A case-control study in Finland investigated home characteristics and levels of various microbial agents, including endotoxin, 3-hydroxy fatty acids (a biomarker of lipopolysaccharide), ergosterol, fungi, and actinomycetes (a large group of gram-positive bacteria), in house dusts of 36 children who had newly diagnosed asthma or who were referred to a hospital because of a history of two or more attacks of wheezing and 36 control children (age range 1 to 7 years old) [27]. Researchers found an increased risk for developing asthma with exposure to higher concentrations of mesophilic actinomycetes, mesophilic and xerophilic fungi, and ergosterol (adjusted OR range 1.08-1.18).…”

Association between domestic mould and mould components, and asthma and allergy in children: a systematic review

“…One small study from Taiwan reported positive associations between exposure to airborne Cladosporium and asthma in school-aged children [35]. However, three publications from Europe could not find an association between higher levels of dust-borne fungal species and asthma [58][59][60].…”