Taxonomy and Clinical Spectra of Fusarium Species: Where Do We Stand in 2014?

Abstract

With the recent change of the botanical code for the names of algae, fungi, and plants, fungi are no longer allowed to have multiple names for their different reproductive stages. Here we discuss that under the new nomenclatural rules and for taxonomic stability, Fusarium is to be preferred above names for some of its known sexual stages like Haemonectria and Gibberella. The genus Fusarium contains emerging etiological agents of disease ranging from onychomycoses, skin and eyeinfections, to deep localized and disseminated infections. Deep infections occur nearly exclusively in immunocompromised patients, while remaining infections primarily affect healthy individuals. Within the large genus, at least seven species complexes comprising multiple species have been implicated in human and animal infections. In this review we give an overview of currently known opportunistic Fusarium species and the infections they cause.

Emergence of fusarioses in a university hospital in Turkey during a 20-year period

“…Fusarium species cause a broad spectrum of infections in humans, including superficial, locally invasive, and disseminated infections [13,14]. Clinical manifestations largely depend on the immune status of the host and the portal of entry, which include paranasal sinuses, lungs, and skin [13].…”

“…Deep and disseminated infections are confined to severely immunocompromised patients. Disseminated infections seem predominantly related to hematological disorders [12], sometimes with a link to a pre-existing nail or cutaneous infection [13,14]. The observed number of fusarioses has been reported to increase over the past several decades: this may be partly due to the growing number of immunocompromised patients and their prolonged average survival time, partly due to prophylactic therapeutic approaches against opportunistic fungal infections which have little impact on Fusarium, and partly to our improved ability to identify the infective agents [14,15].…”

International Evaluation of MIC Distributions and Epidemiological Cutoff Value (ECV) Definitions for Fusarium Species Identified by Molecular Methods for the CLSI Broth Microdilution Method

“…However, the perception is that new generic changes may be suggested, such as the establishment of the genus Bisifusarium to include the more commonly known members of the Fusarium dimerum SC and the name Neocosmospora solani to replace Fusarium solani (6). The most frequent causes of fungal infections are members of three complexes, the F. solani species complex (SC), the F. oxysporum SC, and the Fusarium (Gibberella) fujikuroi SC (which includes, among others, F. verticillioides and F. proliferatum), and the next most frequent causes belong to the F. dimerum SC and F. incarnatum-F. equiseti SC; their distribution could be region dependent (4,(7)(8)(9)(10). Common clinical presentations are onychomycosis, keratitis, allergic disease (sinusitis and bronchopulmonary disease) for nonimmunocompromised patients and disseminated disease, as well as other severe invasive infections, in immunocompromised hosts (e.g., patients with prolonged neutropenia and T-cell immunodeficiency) (1,4,(7)(8)(9)(10)(11)(12)(13).…”

“…The most frequent causes of fungal infections are members of three complexes, the F. solani species complex (SC), the F. oxysporum SC, and the Fusarium (Gibberella) fujikuroi SC (which includes, among others, F. verticillioides and F. proliferatum), and the next most frequent causes belong to the F. dimerum SC and F. incarnatum-F. equiseti SC; their distribution could be region dependent (4,(7)(8)(9)(10). Common clinical presentations are onychomycosis, keratitis, allergic disease (sinusitis and bronchopulmonary disease) for nonimmunocompromised patients and disseminated disease, as well as other severe invasive infections, in immunocompromised hosts (e.g., patients with prolonged neutropenia and T-cell immunodeficiency) (1,4,(7)(8)(9)(10)(11)(12)(13). Amphotericin B lipid formulations, voriconazole, posaconazole, and, to a lesser extent, itraconazole have been recommended or used for the treatment and prophylaxis of Fusarium infections, in addition to surgical debridement and reversal of immunosuppression (14)(15)(16)(17)(18)(19).…”

Challenges in Fusarium, a Trans-Kingdom Pathogen

“…when etiological agents are typed to species level [4]. Eye infections after trauma with soil or plant material commonly occur in warmer drier climates, while in temperate areas (lack of) lens hygiene appears a common source of keratomycosis [5]. Life-threatening, deep and disseminated infections occur in severely immunocompromised patients, where especially leukemic patients are at risk; a relatively innocent dermatological fusariosis may prove to be the portal of entry [6].…”