Table 3.

Morphological features of yeast and mold phases of Emergomyces species (4).

Species	Saprobic phase (24°C)		Thermotolerant phase (37°C)		Comments
	Colony morphology	Microscopic morphology	Colony morphology	Microscopic morphology
Emergomyces pasteurianus	Obverse-Yellowish white, dense, felty to floccose, radially sulcate.!!break Reverse-Ochraceous-buff to warm buff peripherally.	Conidiophores with septa at the base and at conidial insertion, cylindrical, or moderately swollen at the tip. Conidia formed singly or in short chains (2–4), subspherical, 0.9–2.8 × 1.8–3.2 μm, smooth to finely roughened. Some chlamydospore-like cells arise terminally on short lateral branches, with thickened walls and often with a median septum	8 mm diameter, yeast-like, cerebriform, yellowish-white.	Hyphae scant, moniliform, some cells becoming giant cells, 5.4–12 μm wide. Yeast cells arise from giant cells or from fragments of swollen conidiophores or hyphae; small yeasts with narrow-based budding, 2.1–5.1 × 1.6–4.2 μm; larger yeasts 5.0–11.2 × 2.4–6.3 μm, with uni- or bipolar budding from narrow or broad bases.	Conversion to yeast is slower (2–3 weeks) and occurs at higher temperature (37°C) than in Es. africanus and Es. europaeus.
Emergomyces africanus	Obverse-Yellowish-white, glabrous to floccose centrally, radially sulcate.!!break Reverse-Warm-buff to light buff peripherally.	Conidiophores with a septum at the base and at conidial insertion; moderately swollen at the tip with 4–8 conidia borne on narrow pedicels. Conidia single or in short chains (2–4), subspherical, 1.2–3.2 × 1.7–3.8 μm, smooth to finely roughened.	7 mm diameter, yeast-like, cerebriform, yellowish-white.	Hyphae scant. Yeast cells abundant, ovoidal to subspherical, 1.7–5.3 × 0.9–2.2 μm with unipolar budding at a narrow base.	Development of secondary conidiophores leading to a complex cluster of 4–8 conidia and production of small-celled yeasts at 37°C within 1 week.
Emergomyces canadensis	Obverse- Yellowish white, cottony to glabrous, with tufts of hyphae centrally, radially sulcate.!!break Reverse-Ochraceous-buff to warm-buff peripherally.	Conidiophores with septum at the base, cylindrical, or slightly swollen in the middle and at the tip, bearing 1–2 conidia on narrow pedicels. Conidia subspherical, 2.1–3.8 × 1.8–3.4 μm, smooth to slightly roughened.	3 mm diameter, yeast-like, smooth, yellowish-white.	Yeast cells abundant, spherical, 2.2–4.8 μm with uni- or bipolar budding at narrow base. Few short, swollen hyphal elements, and giant cells present.	Closely related to Es. orientalis. Urease test is negative, red pigment produced on BHIA, and TSA at 37°C. In Es. canadensis, optimal sporulation temperature is 24–27°C, time for transformation to yeast at 37°C is fast (1 week).
Emergomyces orientalis	Obverse-Yellowish white, felty with hyphal tufts centrally, radially sulcate.!!break Reverse-Ochraceous-buff to warm-buff peripherally.	Conidiophores cylindrical or slightly swollen in the middle, with a septum at the base, thin secondary conidiophores present. Conidia subspherical, 1.1–2.8 × 1.7–4.8 μm smooth to slightly roughened.	5 mm diameter, yeast-like, cerebriform, yellowish white.	Hyphal elements scant. Yeast cells spherical, 2.0–4.5 μm diam, with uni- or bipolar budding at a narrow base. Few giant cells present.	Produces conidia at 21°C but not at 24°C. Urease test is negative, red pigment produced on BHIA and TSA at 37°C. Time for transformation to yeast at 37°C is slow (2 weeks).
Emergomyces europaeus	Obverse- Dense, white, felty to floccose, radially sulcate, glabrous at the margin.!!break Reverse-Warm-buff to light buff periphally.	Conidiophores unbranched, with septum at the base, cylindrical to slightly swollen at the tip, bearing one or two subspherical, slightly roughened conidia, measuring 2.9–5.7 × 3.0–5.7 μm	4 mm diameter, yeast-like, pasty, cerebriform, tan	Swollen hyphae and giant cells present; yeast cells ovoidal to subspherical, 2.6–5.9 × 17–3.8 μm with uni- or bipolar budding at a narrow base.	Es. europaeus has conidiophores without secondary branches and conidia are larger and more roughened than those of other species. Yeast transformation occurs at a lower temperature (33°C).

BHIA, Brain heart infusion agar; TSA, Trypticase soy agar.