Saksenaea vasiformis
| Saksenaea vasiformis | |
|---|---|
| Scientific classification | |
| Kingdom: | Fungi |
| Division: | Zygomycota |
| Class: | Mucoromycotina |
| Order: | Mucorales |
| Family: | Saksenaeaceae |
| Genus: | Saksenaea |
| Species: |
S. vasiformis S.B.Saksena (1953) |
| Binomial name | |
|
Saksenaea vasiformis S.B.Saksena (1953) |
|
Saksenaea vasiformis is an infectious fungus associated with cutaneous or subcutaneous lesions following trauma. It causes opportunistic infections as the entry of the fungus is through open spaces of cutaneous barrier ranging in severity from mild to severe or fatal. It is found in soils worldwide, but is considered as a rare human pathogen since only 38 cases were reported as of 2012.Saksenaea vasiformis usually fails to sporulate on the routine culture media, creating a challenge for early diagnosis, which is essential for a good prognosis. Infections are usually treated using a combination of amphotericin B and surgery.Saksenaea vasiformis is one of the few fungi known to cause necrotizing fasciitis or "flesh-eating disease".
Saksenaea vasiformis was initially described as a new mucoraceous fungus in a new genus Saksenaea in 1953 by Dr. S. B. Saksena. It was isolated it from Patharia forest soil in India and distinguishably different from other species in morphology of sporangia (flask-shaped) and the method of spore discharge. The name "vasiformis" came from the flask-shape of sporangiophore. Since 1953, it has been isolated from various countries including Panama, Israel, Honduras, and the southern United States. This species is the only species belong to genus Saksenaea, although two new species, which are Saksenaea oblongispora and Saksenaea erythrospora, were proposed in 2010. Detailed microscopic observation displayed similar flask shape of sporangiophores and the phylogenic analysis indicated that these isolates (S. vasiformis, S. oblongispora and S. erythrospora) belong to the same genus Saksenaea.
This species is associated with Apophysomyces elegans, a member of family Mucoraceae. Despite the significant differences of morphological characteristics of sporangia and the manner of sporangium formation, these two species are associated, usually in medical literature, due to similar disease manifestation in human: cutaneous or subcutaneous infections. Infections involving these two species (S. vasiformis and A. elegans) cause rapid necrotizing vasculitis that leads to thrombosis and tissue necrosis in organisms’ vascular lumen.
Saksenaea vasiformis very rapidly grows in growth media, producing sterile hyphae. Induction of sporulation is difficult with routine fungal media used in the most of clinical laboratories, but it can be stimulated to sporulate rapidly (5 to 7 days) by incubating the yeast-malt-dextrose agar at 32 °C. The identification of this species is not problematic after sporulation event because of its characteristic flask-shaped sporangium with spherical venter and a distinct dome-shped columella and dichotomously branched rhizoid complex. On top of the venter, there is a neck with closed apex with a mucilaginous plug. Inside of the neck are the sporangiophores, which are liberated by the dissolution of the mucilaginous plug.
...
Wikipedia