Verticillium Species

The classification of various Verticillium species, such as Verticillium depauperatum, Verticillium rubrum and Verticillium serrae in the genus Verticillium remains doubtful and uncertain. Some authorities feel that they should be included in other genera [531].

Verticillium is a widely distributed filamentous fungus that inhabits decaying vegetation and soil. Some Verticillium species may be pathogenic to arthropods, plants, and other fungi. It is commonly considered as a contaminant. Verticillium may very rarely cause human disease.

The genus Verticillium has four known species; Verticillium affinae, Verticillium albo-atrum, Verticillium fusisporum, and Verticillium luteoalbum. See the list of active names and synonyms for Verticillium spp.

Verticillium has been reported as a possible cause of keratitis in humans [1295, 2202].

Colonies of Verticillium grow moderately rapidly or rapidly. At 25°C and on potato dextrose agar, the colonies are velvety to wooly. From the front, the color is white initially and becomes yellowish, red, pinkish-brown, or green. From the reverse, it is white or brown (rust color) [1295, 2144, 2202].

Septate hyaline hyphae, conidiophores, phialides, and conidia are observed. Conidiophores are hyaline, simple or branched. The branching of the conidiophores occurs in whorls (=verticillate; resembling spokes in a wheel from a central axis) at several levels. Conidiophores bear the phialides. Phialides are very long and are also arranged in verticils (whorls) around the conidiophore. Verticils may be disrupted in slide culture. The apices of the phialides are pointed. Conidia (2-13µm in length) are hyaline or brightly colored, one-celled, and oval to pyriform in shape. They are solitary or form clusters in sticky heads at the tips of the phialides [1295, 2144, 2202].

Acremonium

Verticillium differs from Acremonium by having not solitary but whorls of phialides and branches.

No special precautions other than general laboratory precautions are required.

Very few data are available. Per these data on very limited number of isolates, amphotericin B, ketoconazole, itraconazole, and voriconazole appear active in vitro against Verticillium spp. [2432].

For MICs of various antifungal drugs for Verticillium spp., see our susceptibility database.

PubMed

GenBank

Verticillium spp. The phialides arise in whorls, upon which balls of conidia accumulate at their apices.

References

531. de Hoog, G. S., J. Guarro, J. Gene, and M. J. Figueras. 2000. Atlas of Clinical Fungi, 2nd ed, vol. 1. Centraalbureau voor Schimmelcultures, Utrecht, The Netherlands.

1295. Larone, D. H. 1995. Medically Important Fungi - A Guide to Identification, 3rd ed. ASM Press, Washington, D.C.

2144. St-Germain, G., and R. Summerbell. 1996. Identifying Filamentous Fungi - A Clinical Laboratory Handbook, 1st ed. Star Publishing Company, Belmont, California.

2202. Sutton, D. A., A. W. Fothergill, and M. G. Rinaldi (ed.). 1998. Guide to Clinically Significant Fungi, 1st ed. Williams & Wilkins, Baltimore.

2432. Wildfeuer, A., H. P. Seidl, I. Paule, and A. Haberreiter. 1998. In vitro evaluation of voriconazole against clinical isolates of yeasts, moulds and dermatophytes in comparison with itraconazole, ketoconazole, amphotericin B and griseofulvin. Mycoses. 41:309-319.