Chaetomium sp.



PATHOGENICITY:  Commonly considered a contaminant, occasionally implicated in systemic and cutaneous phacohyphomycosis.

RATE OF GROWTH:  Rapidly matures within 5 days.

COLONY MORPHOLOGY:  Hyphae are septate with large (100-150 x 110-225 um) round, oval or flask-shaped perithecia (best seen on potato dextrose agar) that are olive to brown and fragile and have wavy and/or straight filamentous appendages. Asci are stalked and club shaped containing 4 to 8 spores and usually dissolve soon after release from the ostiole (opening) of the perithecium. Ascospores readily observed are oval or lemon shaped, single celled and usually olive brown but may occur in a variety of sizes, shapes and colors.