DESCRIPTIONS OF MEDICAL FUNGI

Descriptions of Medical Fungi 11
Arthrographis kalrae (Tewari & Macpherson) Sigler & Carmichael
Arthrographis is an arthroconidial mould comprising four species: A. kalrae, A. lignicola,
A. pinicola and A. alba. These fungi are commonly found in environmental samples
(soil, wood, air and water), but are isolated rarely from clinical specimens (Sandoval-
Denis et al. 2014a).
RG-1 organism.
Morphological Description: Colonies with slow to moderate growth, creamy white
to tan-coloured. Initially, yeast-like then developing hyphal growth and conidiophores
subhyaline, narrow, branched, often in bundles, occasionally forming whitish, large 0.5
cm, linear synnemata. Arthroconidia are one-celled, hyaline, smooth-walled, oblong to
cylindrical, with truncate ends, 2.5-9x 1-2 µm. Spherical blastoconidia 2-4 x 2-3 µm,
may also be formed laterally and sessile on undifferentiated hyphae. Chlamydospores
may also be present. Very rarely immature ascomata submerged in the agar are
produced. Growth at 42 O C, and on media containing cycloheximide.
Molecular Identification: ITS and D1/D2 sequencing may be used for accurate
species identification (Sugiura and Hironaga 2010, Halliday et al. 2015).
Key Features: Keratinolytic, in vitro hair perforation positive, growth at 37 O C and
tolerance to cycloheximide.
References: Sugiura and Hironaga (2010), Giraldo et al. (2014), Sandoval-Denis et
al. (2014a), de Hoog et al. (2015).
10 μm
10 μm
a b b
Arthrographis kalrae (a) culture and (b) arthroconidia.
Antifungal Susceptibility: A. kalrae (Australian National data); MIC µg/mL.
No 8
AmB 7 1 5 1
VORI 7 1 3 2 1
POSA 7 1 2 2 2
ITRA 7 1 4 2