practical identification of subcutaneous species

PRACTICAL IDENTIFICATION OF

SUBCUTANEOUS SPECIES

KIMAIGA H.O

MBChB (University of Nairobi)

SUBCUTANEOUS SPECIES

• Acremonium

• Cladosporium

• Fusarium

• Sporotrichox

Acremonium spp• Macroscopic

morphology• SDA colony texture

•Often compact and moist at first,

•Becoming - powdery, suede-like

•Colony color•May be - white, grey,

pink, rose or orange

• Macroscopic morphology

• Lactophenol cotton blue (LCB) stain

•Hyphae

• Fine and hyaline

•Conidia•One celled

•Hyaline or pigmented

•Globose or cylindrical

•Mostly aggregated in shiny heads at the apex of each phialide

Cladosporium

Fusarium spp

• Macroscopic morphology• SDA colony texture

• Fast growing, woolly to cottony, flat, spreading

• Colony color• Front: white, cream, tan, salmon, cinnamon, yellow, red, violet,

pink or purple

• Microscopic morphology• Lactophenol cotton blue (LCB) stain• Phiolides

• Cylindrical with a small collarette• Solitary or produced as a component of a complex branching

system• Monophialides and polyphialides (in heads or chains) may be

observed

• Macroconidia• Produced from

phialides on unbranched or branched conidophores

• Thick walled• Smooth and cylindrical

or sickle shaped• Distinct basal foot cell

and painted distal ends• Tend to accumulate in

balls or rafts

• Microconidia• Formed on long or

short simple conidophores

• One celled, occasionally 2 or 3 celled

• Smooth, hyaline, ovoid to cylindrical

• Arranged in balls (occasionally in chains)

• Chlamydospores: when present• Sparse,• In pairs, clumps or

chains• Thick walled• Hyaline• Intercalary or terminal

Fusarium spp

S.schenckii

• Macroscopic morphology• SDA colony texture

• Moist and glabrous• Wrinkled and folded

surface• Some spp may produce

short arial hyphae

• Colony color• Pigmentation may vary

from white to cream to black

• Macroscopic morphology• Lactophenol cotton blue

(LCB) stain

• Conidopheres:• Arise at right angles from

the septate hyphae• Visually: solitary, erect

and tapered towards the apex

• Conidia:• Formed in clusters on tiny

denticles• Arrangement often

suggestive of a flower• Ovoid or elongated• Hyaline• One celled and smooth

walled