ScopulariopsisBy Diane Green, EMLab P&K Analyst In 1907, Bainier made the initial identification of Scopulariopsis with the species S. brevicaulis. Since then several other species have been identified, including S. acremonium, S. asperula, S. brumptii, S. flava, S. fusca, and S. koningii. Scopulariopsis is a fungus that produces one-celled, colorless to brown, pear-shaped spores in chains. The characteristic that usually makes these spores easy to identify on a spore trap (versus other chain producing fungi such as Penicillium, Aspergillus, and Paecilomyces, which are hard to distinguish from one another) is the distinctly truncated base. These spores can be smooth or roughened, depending on the species and also on the age of the spores. As the spores of different species spores mature, they may become finely to coarsely roughened.
Figure 1: Close up view of distinctive Scopulariopsis spores. The spore-bearing structure of Scopulariopsis is called an annellophore, a word that describes the way the spores are formed. The spores are produced in chains, and as the second spore is produced, the first is pushed away from the annellophore leaving a cylinder of cell wall material attached to the annellophore opening. When the third spore is produced, the second spore is pushed away leaving a second ring, and so forth. These rings accumulate and are characteristic of annellophores. Scopulariopsis may produce a single annellophore or a broom-like structure called a scopula. The scopula is similar in appearance to the penicillus in Penicillium. However, the spores of Penicillium are produced on phialides, which do not have the characteristic apical rings of annellophores. The colonies of Scopulariopsis grow at a moderate to rapid rate. They have a velvety to powdery texture, and the surface color is white, cinnamon, grayish or black, never blue or green as in Penicillium. Many species of Scopulariopsis are known to have a sexual stage in the ascomycetous genus Microascus.
Figure 2: Scopulariopsis spores growing from a scopula (arrow). Several Scopulariopsis species are associated with infections causing skin lesions, affecting the nails (especially toenails) and causing opportunistic infections in immunocompromised people. Certain species are also known to attack bee larvae and silkworms. Scopulariopsis is occasionally recovered from house dust where it probably uses skin scales for food. It is also occasionally recovered from both indoor and outdoor air. References: 2. de Hoog, G.S., Guarro, J., Figueras, Gene and M.J (2000): Atlas of Clinical Fungi, Second Edition. Centraalbureau voor Schimmelcultures, The Netherlands. Pp 902-916. 3. Ellis, M.B. (1971): Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew. Pp 326-329. |
