Toxins from strains of Penicillium chrysogenum isolated from buildings and other sources.

In 2004, Scott et al. (Mycologia 2004; 96: 1095-1105) determined that there are four molecular species within P. chrysogenum, one of which (clade 4) was dominant in isolates in house dust in approximately 100 homes in southern Ontario, Canada. We collected additional strains from buildings across Canada and obtained some from DAOM. The large majority of our strains were in clade 4, with a modest number of strains in Clade 1. Because these strains came from across Canada, the dominance of clade 4 in buildings is apparently widespread. Most strains tested produced penicillin G, roquefortine C and unexpectedly, meleagrin in high yield. Additionally, there appeared to be strains differentiated by their ability to accumulate xanthocillin X. These studies allowed focused toxicity studies in vivo and with primary lung cell cultures to be undertaken on the basis of reliable information of the toxins that should be studied.