Wangiella Mold Species
Wangiella
dermatitidis
is a causative agent of (Information from www.doctorfungus.org @ 2005)
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Taxonomic Classifications
Kingdom: FungiOrder: ChaetothyrialesGenus: Wangiella Wangiella Mold Pictures
(Image Courtesy of www.doctorfungus.org @ 2005) Microscopic morphology of Wangiella dermatitidis showing flask - shaped to cylindrical phialides without distinctive collarettes. Cultures grow at 42°C.
(Image Courtesy of www.doctorfungus.org @ 2005)
Colony composed of both budding yeast and hyphae on Sabouraud glucose agar.
(Image Courtesy of www.doctorfungus.org @ 2005)
Clinical slide of subcutaneous phaeohyphomycosis following a non - penetrating injury. The lesion, on the dorsum of the right thumb, was fluctuant, tender, blue - gray and had no connection to the surface.
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Ecology Wangiella is a dematiaceous, cosmopolitan saprobic fungus that inhabits the soil and plant material. Wangiella species is an occasional agent of various infections in humans.
Species The only species classified under the genus Wangiella is Wangiella dermatitidis. However, the taxonomic position of this species is not totally consistent as some authorities would classify it in the genus Wangiella as Wangiella dermatitidis, others would prefer to classify it in the genus Exophiala as Exophiala dermatitidis.
Pathogenicity and Health Effects Wangiella dermatitidis is considered as an occasional agent of subcutaneous phaeohyphomycosis and of disseminated infection in the immunocompromised patient at times. The infection is usually subsequent to the traumatic implantation of the fungus into the dermis, and the fungus normally remains localized. Wangiella dermatitidis is a neurotropic fungus. Infections in the central nervous system and as well as cases of keratitis, otitis, pneumonia, and endocarditis have been reported. In animals, Wangiella dermatitidis may cause bovine abortion and still birth.
Macroscopic Appearance Ø Growth rate is slow and colonies are initially moist, shiny, yeast – like becoming velvety around the periphery after incubation at 25°C; Ø The surface colony color is black to olive black and as well as on the reverse; Ø Aerial hyphae develop after three to four weeks of incubation; and Ø Wangiella dermatitidis has the ability to grow at high temperatures, as high as 42°C and does not assimilate potassium nitrate.
Microscopic Appearance Ø Septate brown hyphae, conidiophores, phialides, and yeast cells are present; Ø Brown, budding, yeast – like cells are dominant in young culture when examined microscopically but as the culture gets older, hyphae and phialides are formed from these yeast – like cells; Ø Phialides are brown, branched, flask – shaped to cylindrical, and without collarettes; Ø Conidiophores are commonly difficult to differentiate from vegetative hyphae; and Ø Conidia are unicellular, brown, round - to oval – shaped, with size ranging from 2 – 4 x 2.5 – 6 µm, and are found in clusters at the tips of the phialides and down the sides of the conidiophores; Ø The difference between Exophiala species and Wangiella dermatitidis is that the former produces annellides while the latter produces phialides. However, it must also be noted that annellide production has been observed in some isolates of Wangiella dermatitidis.
Laboratory Precautions General laboratory precautions are required, no special safety measures needed.
Susceptibility
Surgical excision
appears as the preferred treatment in cases with subcutaneous infection.
Amphotericin B alone or in combination with ketoconazole and rifampin has
also been used. However, best medical treatment of Wangiella
infections is not well – known. |
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The mycological information gathered and
A
Clinical Laboratory Handbook:
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