Biodiversity and human-pathogenicity ofPhialophora verrucosaand relatives inChaetothyriales

Abstract

Phialophora as defined by its type species P. verrucosa is a genus of Chaetothyriales, and a member of the group known as ‘black yeasts and relatives’. Phialophora verrucosa has been reported from mutilating human infections such as chromoblastomycosis, disseminated phaeohyphomycosis and mycetoma, while morphologically similar fungi are rather commonly isolated from the environment. Phenotypes are insufficient for correct species identification, and molecular data have revealed significant genetic variation within the complex of species currently identified as P. verrucosa or P. americana. Multilocus analysis of 118 strains revealed the existence of five reproductively isolated species apparently having different infectious potentials. Strains of the sexual morph Capronia semiimmersa cluster within P. americana. The newly defined taxa differ markedly in their predilection for the human host.

The genus Anthopsis and its phylogenetic position in Chaetothyriales

“…Strains described under the genus name Anthopsis had a unique morphology with conidium production through collarettes which were located at the base of the phialides. Occasionally, some phialides showed conidiogenesis at the apex or around the middle of the phialide resembling the classical morphology of Phialophora . Some conidiogenous cells were integrated in ascending hyphae, producing sessile collarettes alongside hyphae.…”

“…Gams noted that Phialophora is phylogenetically very diverse. The type species P. verrucosa belongs to Chaetothyriales in the carrionii‐clade of the family Herpotrichiellaceae . CBS 263.77, type strain of the generic type Anthopsis deltoidea was later erected to family level as Cyphellophoraceae by Réblová et al .…”

“…Occasionally, some phialides showed conidiogenesis at the apex or around the middle of the phialide resembling the classical morphology of Phialophora. 5 Some conidiogenous cells were integrated in ascending hyphae, producing sessile collarettes alongside hyphae. The nearly invariable presence of distinct collarettes and the morphogenetic pattern of the conidia, whose wall seems to be formed de novo and cluster in groups near the base of the conidiogenous cells 1 led us to confirm that the conidiogenesis represents a typically phialidic process.…”

“…Phialophora in the classical sense is, however, phylogenetically heterogeneous . Its type species, P. verrucosa belongs to the family Herpotrichiellaceae , order Chaetothyriales …”

“…4 Its type species, P. verrucosa belongs to the family Herpotrichiellaceae, order Chaetothyriales. 5 Two additional species have been described in the genus Anthopsis, viz. A. catenata 6 (CBS 492.81) and A. microspora.…”