Species name/ common name

Fusarium solani (Teleomorph: Nectria haematococca)

Natural habitat

It is frequent isolated from soil and plant debris.

Geography

Worldwide distribution.

Frequency

The real frequency of this pathogen is unknown. Apart from keratitis, it is an infrequent cause of fungal infections but it remains the most frequent species of Fusarium causing human infections.

Diseases

F. solani causes the following diseases:

•     Keratitis is the most frequent entity. Outbreaks have been described associated with the use of contact lenses;
•     Endophtalmitis;
•     Onychomycosis;
•     Cutaneous and subcutaneous infections;
•     Arthritis and mycetoma;
•     Sinusitis;
•     Disseminated infections; in immunosupressed patients mainly haematological and associated with a mortality close to 100%.

Culture peculiarities

Colonies of rapid growth. The mycelium is white to cream. Sometimes some areas of green or blueish-brown are developed. Conidiophores are long in comparison with other human pathogenic species. Microconidia abundant and characteristic (bean shape). Strains isolated from humans do not usually produce macroconidia. Chlamydospores frequent.

Antifungal resistance (intrinsic and acquired)

Fusarium solani is a highly resistant fungus. The most active antifungal is amphotericin B. Voriconazole can show activity against some isolates but it is not the rule. The rest of azole antifungals are inactive as well as the echinocandins.

Biosafety level

This fungal species must be managed in a laboratory with safety containment level 2.

Industrial use

Produces ciclosporin A, an immunosuppressive agent, which transformed the outcome of organ transplantation. The related species Fusarium graminearum is used to produce the food mycoprotein Quorn.

Key reading: Tupaki-Sreepurna A, Kindo AJ. Fusarium: The versatile pathogen. Indian J Med Microbiol. 2018 Jan-Mar;36(1):8-17. Review.