The in vitro isolation of Blastomyces dermatitidis from a woodpile in north central Wisconsin, USA

Environmental isolations of the dimorphic fungus, Blastomyces dermatitidis, the aetiologic agent of blastomycosis are rare, and have usually involved animal innoculation techniques. We report the in vitro isolation of B. derm atitidis from a woodpile in November 1997, from a private property in a hig hly endemic area of north central Wisconsin, USA. The woodpile was 73 m fro m the Wisconsin River and 5 m from a kennel which had housed nine dogs over the past 14 years, four of which had been diagnozed with blastomycosis. On e of 19 samples from the property yielded B. dermatitidis after 37 degrees C incubation in a neutral aqueous solution of allantoin, Tween-80, potassiu m phosphate, magnesium sulphate, penicillin and streptomycin followed by pl ating on yeast-extract phosphate agar at 20 degrees C. Refinements of this technique may help further elucidate the ecological niche of B. dermatitidi s.