Mold Library
Paecilomyces
Distribution
Paecilomyces is a cosmopolitan fungus that is commonly isolated from soil, dust, decaying plants, food products, insects, and, less frequently, from air.
Growth Characteristics
Paecilomyces grows rapidly. The colonies are flat, and powdery or velvety in texture. The color is initially white, and may become buff, suede or brightly colored with age. Older cultures may produce a sweet aromatic odor. Some species are thermophilic and can grow well at temperatures as high as 122oF (50oC).
Microscopic Characteristics
Species of Paecilomyces produce simple or branched conidiophores bearing two to several phialides that are swollen at the base and gradually narrow into a long beak. Spores are produced in long chains from the tips of the phialides, are either colorless or slightly pigmented, and may have a variety of shapes from spherical to fusiform. Paecilomyces is often confused with Penicillium; however, Paecilomyces may be distinguished by its long slender divergent phialides and colonies that are never green.
Health Effects
Paecilomyces acts as an allergen. Some species of Paecilomyces can be pathogenic in humans where they can produce a variety of infections throughout the body, usually following traumatic implantation. Paecilomyces may also cause opportunistic mycoses in immunocompromised hosts.