A just-published article by Desroches et al, “Extrolites of Wallemia sebi, a very common fungus in the built environment,”in the journal Indoor Air describes a previously unidentified metabolite of Wallemia sebi , a very common fungus in houses worldwide, although relatively more common in north temperate climates. The authors (including David Miller) write that it is well-known as a contaminant of salty and sweet foods. Domestic and workplace exposure are known to result in IgE sensitization, and some metabolites have been reported.
The article reports new work from Miller’s lab that “…provides the sequence of the primary human antigen and describes the metabolites from damp building strains including a new compound, 1-benzylhexahydroimidazo [1,5-É‘] pyridine-3,5-dione which [they] call wallimidione.” Of the atopic patient sera examined by the authors, “the percentage with antibodies to the antigen was similar to that of the most common species of Penicillium in damp buildings.”
The authors suggest that studies of damp building fungi need to use methods capable of detecting this organism more reliably than in the past.
The abstract is viewable here, although a subscription to the journal is necessary to view the whole article for those without library access. Members of ISIAQ gain access by logging in on the ISIAQ web page and then clicking on the journal icon.
“Most toxic” is a good headline; the new metabolite is more toxic than the compounds known from this fungus. Tests are being completed for the effects on lung biology of wallimidione as well as compounds from building strains of C. globosum (Mycotoxin Research 2013 29:47; Tetrahedron Letters 2013 54:568) and P. corylophilum (J Natural Products 10.1021/np4005486; Mycologia in press).
My attention to this fungus was drawn because we knew it was very common in some homes from the Canadian housing and health studies and brought into greater focus by some Sloan funded work (Proc Natl Acad Sci USA 107:13748).