DESCRIPTIONS OF MEDICAL FUNGI

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Descriptions of Medical Fungi
PREFACE
Key Morphological Characters
Culture Characteristics:
• Surface texture [glabrous, suede-like, powdery, granular, fluffy, downy, cottony]
• Surface topography [flat, raised, heaped, folded, domed, radial grooved]
• Surface pigmentation [white, cream, yellow, brown, pink, grey, black etc]
• Reverse pigmentation [none, yellow, brown, red, black, etc]
• Growth rate [colony diameter 5 cm in 15 days]
• Growth at 37 O C, 40 O C, 45 O C.
Zygomycota. Sporangia characteristics:
• Arrangement of sporangiospores [multispored, sporangiola, merosporangium]
• Arrangement of sporangiophores [unbranched often in groups or frequently branched]
• Sporangium shape [pyriform, spherical, flask-shaped etc]
• Sporangium size [100 μm diam.]
• Columella [Present or Absent]
• Apophyses [Present or Absent]
• Sporangiophore height [1 mm]
• Rhizoids [Present or Absent] (look in the agar)
• Sporangiospore size [6 μm]
Hyphomycetes - Conidial Moulds
1. Conidial characteristics:
• Septation [one-celled, two-celled, multicelled with transverse septa only, or multicelled with
both transverse and longitudinal septa]
• Shape [spherical, sub-spherical, pyriform, clavate, ellipsoidal, etc]
• Size [need a graduated eyepiece, length 10 μm]
• Colour [hyaline or darkly pigmented]
• Wall texture [smooth, rough, verrucose, echinulate]
• How many conidial types present? [i.e. micro and macro]
2. Arrangement of conidia as they are borne on the conidiogenous cells:
• Solitary [single or in balls]
• Catenulate (in chains) [acropetal (youngest conidium at the tip) or basipetal (youngest
conidium at the base]
3. Growth of the conidiogenous cell:
• Determinant (no growth of the conidiophore after the formation of conidia)
• Sympodial (a mode of conidiogenous cell growth which results in the development of
conidia on a geniculate or zig-zag rachis)
4. Type of conidiogenous cell present:
• Non-specialised
• Phialide (specialised conidiogenous cells that produces conidia in basipetal succession
without increasing in length)
• Annellide (specialised conidiogenous cell producing conidia in basipetal succession by a
series of short percurrent proliferations (annellations). The tip of an annellide increases in
length and becomes narrower as each subsequent conidium is formed)
5. Any additional features present:
• Hyphal structures [clamps, spirals, nodular organs, etc]
• Synnemata, Sporodochia, Chlamydoconidia, Pycnidia
• Confirmatory tests for dermatophytes