Scedosporium spp. from Clinical Setting in Argentina, with the Proposal of the New Pathogenic Species Scedosporium americanum

Abstract

Species of the genus Scedosporium (family Microascaceae, phylum Ascomycota) are responsible for a wide range of opportunistic human infections, and have a low susceptibility to most antifungal drugs. It is well known that the pattern of Scedosporium species distribution varies according to geographic region. To assess the diversity of Scedosporium species in Argentina involved in human infections, we carried out a retrospective study reviewing 49 strains from clinical samples sent for diagnosis to the National Clinical Mycology Reference Laboratory between 1985 and 2019. Then, a phenotypic characterization, a phylogenetic study and and in vitro susceptibility test to antifungals were carried out. An analysis of combined nucleotide sequences dataset of the internal transcribed spacer of the ribosomal DNA (ITS) and of a fragment of the β-tubulin gene (BT2) demonstrated that 92 % of the strains belonged to the species S. boydii, S. apiospermum and S. angustum, all them pertaining to S. apiospermum species complex. However, two strains (4%) were identified as S. aurantiacum, a species never reported in clinical settings in the Americas’. Surprisingly, one of them displayed a polycytella-like conidiogenesis, up to date only reported for S. apiospermum. In addition, the strain DMic 165285 was phylogenetically located far away from the rest of the species, so is proposed as the novel species Scedosporium americanum. On the other hand, from all seven antifungals tested, voriconazole and posaconazole were the most active drugs against Scedosporium spp.

A New Genus of the Microascaceae (Ascomycota) Family from a Hypersaline Lagoon in Spain and the Delimitation of the Genus Wardomyces

“…While members of Microascaceae have a global distribution, only a few have been initially discovered in Spain, such as Wardomycopsis litoralis and Pseudoscopulariopsis schumacheri [20,83]. Although most of the members of Microascaceae are not usually isolated from extreme environments [29,[84][85][86], some species of the genera Microascus and Scopulariopsis have been isolated from halophyte plants and salt marshes, respectively [87,88]. Moreover, only two species of this family were first isolated from salty habitats: Wardomyces pulvinatus and Wardomycopsis litoralis [83,89].…”

Eye Infections Caused by Filamentous Fungi: Spectrum and Antifungal Susceptibility of the Prevailing Agents in Germany

“…Chaetomium anastomosans (sibling species of C. globosum) [30] and Purpureocillium sodanum (sibling species of P. lilacinum) [31] are recently described species, cases of which might have previously been assigned to their sibling species. Other species such as Aspergillus cibarius [32], A. udagawae [33], Fusarium bostrycoides (as FSSC 25), F. tonkinense (as FSSC 9) [9], Penicillium rubens [34], and Scedosporium dehoogii [35] have been reported only once before in connection with eye infections. Among all filamentous fungi associated with eye infections, Fusarium is the dominating genus, at nearly 47.3%.…”

A Lateral-Flow Device for the Rapid Detection of Scedosporium Species

“…The Scedosporium species most commonly associated with life-threatening infections are S. apiospermum, S. aurantiacum, and S. boydii [8,[57][58][59][60][61]. Detection of these pathogens relies on a combination of techniques including histological examination and in situ hybridisation of tissue samples [62], isolation of the fungi from biopsy samples using semi-selective or selective media and microscopical examination of cultures for characteristic morphological features [58,63], with species identification requiring matrix-assisted laser desorption/ ionisation-time-of-flight mass spectrometry (MALDI-TOF MS) [64] or molecular methods such as polymerase chain reaction [58,63].…”