Species Diversity, Distribution, and Phylogeny of Exophiala with the Addition of Four New Species from Thailand

Abstract

The genus Exophiala is an anamorphic ascomycete fungus in the family Herpotrichiellaceae of the order Chaetothyriales. Exophiala species have been classified as polymorphic black yeast-like fungi. Prior to this study, 63 species had been validated, published, and accepted into this genus. Exophiala species are known to be distributed worldwide and have been isolated in various habitats around the world. Several Exophiala species have been identified as potential agents of human and animal mycoses. However, in some studies, Exophiala species have been used in agriculture and biotechnological applications. Here, we provide a brief review of the diversity, distribution, and taxonomy of Exophiala through an overview of the recently published literature. Moreover, four new Exophiala species were isolated from rocks that were collected from natural forests located in northern Thailand. Herein, we introduce these species as E. lamphunensis, E. lapidea, E. saxicola, and E. siamensis. The identification of these species was based on a combination of morphological characteristics and molecular analyses. Multi-gene phylogenetic analyses of a combination of the internal transcribed spacer (ITS) and small subunit (nrSSU) of ribosomal DNA, along with the translation elongation factor (tef), partial β-tubulin (tub), and actin (act) genes support that these four new species are distinct from previously known species of Exophiala. A full description, illustrations, and a phylogenetic tree showing the position of four new species are provided.

Exophiala yunnanensis and Exophiala yuxiensis (Chaetothyriales, Herpotrichiellaceae), two new species of soil-inhabiting Exophiala from Yunnan Province, China

“…The present work increased the number of Exophiala species to 70 in the world (Crous et al 2022;Thitla et al 2022). In China, Yunnan Province has diverse climate and vegetation, which provides natural advantages for the study of environmental microbial diversity.…”

“…The genus is characterised by annellidic conidiogenous cells producing slimy heads of conidia, conidiophores upright or bent, not or irregularly branched, smooth, light olive to brown. However, there are several synanamorphs recorded in this genus ( Thitla et al 2022 ). Nearly all species are recognisable within the order by the way they produce cells by budding ( De Hoog et al 2011 ).…”

“…In the past, taxonomic and diagnostic schemes for Exophiala were morphological characteristics, but the anamorphic states of some species are highly pleomorphic ( De Hoog et al 1995 ; Haase et al 1995 ; Thitla et al 2022 ), which make them difficult to be recognised and circumscribed ( Naveau 1999 ; Zeng and De Hoog 2008 ), so only a small number of Exophiala species are, in fact, recognisable using morphology. With the development of molecular systematics, more and more species were redefined, re-designated or described mainly depending on genetic, morphological, physiological and ecological features ( Haase et al 1999 ; De Hoog et al 2003; Vitale et al 2003 ; De Hoog et al 2006 ).…”

“…& Miyaji, respectively. Currently, 68 species have been accepted into this genus after a brief review of Thitla et al (2022) and Crous et al (2022) , who described new species from Thailand and Australia.…”

Destructive Facial Plaque and Palatal Perforation in a Middle-Aged Woman

“…Treatment with azole antifungal agents (itraconazole, posaconazole, or voriconazole) is the mainstay of treatment. Other treatment options include amphotericin B, terbinafine, flucytosine, and griseofulvin along with physical modalities, such as excision, heat therapy, and cryotherapy …”