(described by Kunze in 1817)
Description and Natural Habitats
Arthrinium is a cosmopolitan filamentous fungus isolated from plant debris and soil.
Pathogenicity and Clinical Significance
There are no infections so far reported due to Arthrinium in humans or animals. Since Arthrinium is cosmopolitan in nature, it is an occasional laboratory contaminant.
It grows rapidly, reaching a colony size of 3 to 9 cm in diameter following incubation at 25°C for 7 days on potato glucose agar. The colonies are woolly to cottony and white with brown spots on the surface. The reverse side is pale .
The hyphae are septate and hyaline and bear pale, short or elongated conidiogenous cells which appear inflated at their base where they originate from the hyphae. From these conidiogenous cells, brown, lens- or lentil-shaped conidia are formed in clusters. The conidia typically have germ slits passing through the two poles. .
Some Arthrinium strains may sporulate slowly and require differentiation from dermatophytes and dimorphic fungi.
Key Features for Differentiation 
The conidia of Arthrinium are in clusters, whereas those of Stephanosporium are in chains.
Arthrinium is sensitive to cycloheximide. This property helps in differentiation from dermatophytes and dimorphic fungi.
No special precautions other than general laboratory precautions are required.
No susceptibility data are available.