(Martius) Saccardo (1881)

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 woolly to cottony with cream to white aerial mycelium and a cream reverse. Sporodochia (clusters of conidiogenous cells/conidia viewed as raised areas with the naked eye) may form and are usually moist and cream-colored. Sporodochia may occasionally be blue-green or blue, but never orange [2202], [1630].

Microscopic morphology

Hyphae are septate and hyaline. Conidiophores are simple (non-branched) or branched monophialides (phialides with a single opening). Macroconidia are moderately curved, stout, thick-walled, usually 3-5 septate, measure 4-6 x up to 65 µm long, and are borne on short conidiophores that soon form sporodochia. Microconidia are borne from long monophialides, are one to three-celled, 2-5 x 8-16 µm long, and occur in false heads only (in clusters of conidia at the tip of the phialide). Chlamydoconidia are present (sometimes profuse) and occur both singly and in pairs [2202], [1630].

Special notes

Fusarium solani is the most common Fusarium species recovered in humans and animals. It is an etiologic agent in keratitis, endophthalmitis, cutaneous infections, burn patients, mycetoma, onychomycosis, sinusitis, pulmonary disease, endocarditis, catheter infections, and septic arthritis. See Fusarium spp. for literature citations. Neutropenic patients with hematologic malignancies and those undergoing bone marrow transplantation are at high risk for disseminated disease. It has also been reported in hospital water distribution systems [64] . Molecular characterization suggests that clinically significant isolates vary considerably and are best referred to as members of the “Fusarium solani species complex” [1665], [2196]. Cylindrocarpon lichenicola and Acremonium falciforme have recently been added to the F. solani species complex based upon molecular studies and a spectrum of opportunistic disease similar to that seen for F. solani [2196]. This species is quite easily recognized based upon its cream color, long monophialides, and microconidia in false heads only. Lavender isolates may be seen in cases of mycetoma [2196].

FTL* in vitro susceptibility data

1.0 µg/ml=2 >8.0 µg/ml=17 2.0 µg/ml=2
2.0 µg/ml=15 4.0 µg/ml=2
4.0 µg/ml=10 8.0 µg/ml=15
8.0 µg/ml=1 >8.0 µg/ml=8
16.0 µg/ml=1
Drug/N AMB/29 ITRA/17 VORI/27
MIC Range 1.0-16 >8.0 2.0->8.0
MIC50 2.0 >8.0 8.0
MIC90 4.0 >8.0 >8.0

* Fungus Testing Laboratory unpublished data (NCCLS M38-A)