Fusarium and Neocosmospora: fungal priority pathogens in laboratory diagnosis

Figures & data

Figure 1. Most common species of Fusarium and Neocosmospora isolated in human diseases. *Mycetoma has poor reports in this group. Data obtained from (Al-Hatmi, Hagen, et al. 2016; Guevara-Suarez et al. 2016; Muraosa et al. 2017; Walther et al. 2017; Rosa et al. 2019; Herkert et al. 2019; Najafzadeh et al. 2020; Oliveira dos Santos et al. 2020; Huang et al. 2022).

Figure 2. Growth on “C” pattern of Neocosmospora solani on potato dextrose agar after 48 h incubation at 25 °C.

Figure 3. Neocosmospora and Fusarium clinical species. (A–C) N. solani: conidiophores, macro- and microconidia, and chlamydospores, respectively. (D–F) N. keratinoplastica: macro, microconidia, and chlamydospores, respectively. (G,H) N. falciformis: macroconidia and chlamydospores, respectively. (I) F. oxysporum: monophialides producing microconidia. (J) F. fujikuroi: Mono-, polyphialides, and microconidia. (K,L) F. verticillioides: monophialides producing conidia in chains. Scale bars: (A–L) = 10 µm.

Table 1. Phenotypical characteristics of some clinically relevant species of Fusarium and Neocosmospora.

Species	The macroscopy description on PDA	Microscopy description on CLA (carnation leaf agar)
		Macroconidia	Microconidia	Chlamydospore	Phialides
Neocosmospora solani (Leslie and Summerell 2006; Schroers et al. 2016)	Colony pigmentation: pale yellow to pale salmon; colony reverse in a gradient from Maize Yellow in the middle to yellowish white at the margin. Aerial mycelium: cottony and forms distinct concentric rings.	Shape: falcate slightly curved and often more strongly curved at the tip, base broadly pedicellate. Apical cell: blunt and rounded. Basal cell: straight to almost cylindrical, usually with a notched or rounded end. Number of septa: 3–5.	Shape: ellipsoidal to falcate. Number of septa: 0–2 septa. Comment: abundant.	Arrangement: one- or two-celled. Shape: globose. Wall: smooth to rough. Comment: abundant.	Monophialides
Neocosmospora keratoplastica (Nalim et al. 2011)	Colony color: white, salmon, peach, vinaceous gray, pale olivaceous gray; reverse pale olivaceous gray, flesh, salmon, olivaceous buff, ocherous, and pale luteous. Aerial mycelium: ranging from sparse to dense floccose.	Shape: usually cylindrical and gently curved, sometimes falcate, with dorsal and ventral lines nearly parallel or gradually wider basally. Apical cell: acute. Basal cell: distinct foot shape. Number of septa: 3–5.	Shape: oval, fusiform, pyriform, napiform, or cylindrical. Number of septa: 0–3. Comment: abundant.	Arrangement: single, frequently in pairs. Shape: subglobose. Wall: smooth. Comment: formed after several weeks.	Monophialides
Neocosmospora falciformis	Colony color: white to yellow. Aerial mycelium: no clear information.	Shape: falcate and dorsiventral. Apical cell: pointed. Basal cell: barely notched. Number of septa: 3–4.	Shape: elongated oval and obovoid with a truncated base. Number of septa: 0–1.	Arrangement: single, in a cluster, or in chains. Shape: globose, subglobose. Wall: rough.	Monophialides
Fusarium oxysporum	Colony color: surface pale vinaceous, reverse vinaceous to rosy vinaceous. Aerial mycelium: floccose and abundant.	Shape: falcate, curved dorsoventrally with almost parallel sides tapering slightly toward both ends. Apical cell: blunt to papillate, curved. Basal cell: blunt to foot-like. Number of septa: 3–5.	Shape: ellipsoidal to falcate. Number of septa: 0–1. Comment: abundant.	Arrangement: single. Shape: globose to subglobose. Wall: smooth.	Monophialides
Fusarium proliferatum (Yilmaz et al. 2021)	Colony color: white to pale pink, reverse with pale grayish ruby center fading into a grayish rose, becoming dark violet to blue at center with age. Aerial mycelium: floccose.	Shape: straight to falcate, tapering toward the basal part, moderately to strongly curved, and slender. Apical cell: papillate. Basal cell: foot-shaped to barely notched. Number of septa: 3–4.	Shape: ovoid to pear-shaped Number of septa: 0 to rarely 1. Comment: abundant, and in chains.	Absent	Mono- and polyphialides
Fusarium fujikuroi (Leslie and Summerell 2006)	Colony color: initially, white mycelia that become gray, violet, or magenta with age. Aerial mycelium: no clear information.	Shape: relatively slender, medium length with no significant curvature. Apical cell: tapered. Basal cell: poorly developed. Number of septa: 3–5.	Shape: oval to club-shaped with a flattened base. Pyriform could be present. Number of septa: 0–1. Comment: abundant, and in chains.	Absent	Mono- and polyphialides
Fusarium verticillioides (Leslie and Summerell 2006)	Colony color: initially white mycelia but may develop violet pigments with age. Aerial mycelium: no clear information.	Shape: long and slender, slightly falcate, or straight. Apical cell: curved and often tapered to a point. Basal cell: notched or foot-shaped. Number of septa: 3–5. Comment: difficult to find.	Shape: oval to club-shaped with a flattened based. Number of septa: 0. Comment: abundant, and in chains.	Absent	Monophialides

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