Fusarium semitectum
Berkeley & Ravenel (1875)
syn.: Fusarium incarnatum
(Roberge) Saccardo(1886)
Macroscopic morphology
Macroscopic morphology may vary significantly on different media, and descriptions here are based upon growth on potato flakes agar at 25°C with on/off fluorescent light cycles of approximately 12 hours each. Rapid growth. Colonies are floccose with dense aerial mycelium that is salmon to tan to brown with a brown reverse. Sporodochia may be present and are light orange. [2202], [1630].
Microscopic morphology
Hyphae are septate and hyaline. Conidiophores simple or branched monophialides and polyphialides. Microconidia are sparse or absent. Macroconidia are of two types. Those borne in the aerial mycelium are mostly straight, 3-5 septate, and measure 7.5-35 x 2.5-4 µm. Macroconidia borne in sporodochia are curved, possess a foot cell, are 3-7 septate, and measure 20-46 x 3-5.5. Chlamydoconidia are present but may be sparse, are brown, and occur singly or in short chains. [2202], [1630].
Special notes
Fusarium semitectum is readily distinguished from other clinically important fusaria by the color of the colony, the paucity of microconidia, and the shape of the aerial and sporodochial macroconidia. Fungus Testing Laboratory isolates are from burn patients, a case of endocarditis following aortic valve replacements, and several unpublished cases of keratomycosis in the Rio Grande Valley. It has also been documented as the etiologic agent in necrotizing scute disease in the Texas tortoise [1965].
FTL* in vitro susceptibility data
| AMB | ITRA | VORI |
|---|---|---|
| 4.0 µg/ml=1 | >8.0 µg/ml=1 | 4.0 µg/ml=1 |
| Drug/N | AMB/1 | ITRA/1 | VORI/1 |
|---|---|---|---|
| MIC Range | 4 | >8.0 | 4.0 |
* Fungus Testing Laboratory unpublished data (NCCLS M38-A)