Phialemoniopsis limonesiae sp. nov. causing cutaneous phaeohyphomycosis in an immunosuppressed woman

Abstract

Rare or opportunistic fungal infections are mostly described in immunosuppressed patients. We present a case of a cutaneous phaeohyphomycosis that developed on the dorsal foot in an immunosuppressed woman suffering from AIDS, caused by a novel Phialemoniopsis species. It clinically presented as an indurated violaceous plaque, surmounted by nodules exuding a sero-purulent discharge. A filamentous fungus was isolated from pus and cutaneous biopsy. ITS and LSU sequences phylogenetically resolved the fungus as an unknown species of Phialemoniopsis, which is an unresolved family within Sordariomycetes. In this study we describe the new species as Phialemoniopsis limonesiae, which clusters on a single branch clearly separated from its closest phylogenetic neighbours. This new strain showed low MIC to itraconazole, voriconazole and posaconazole.

Phaeohyphomycosis: A Review

“…Another unique case caused by Peyronellae spp. involved a 64-year-old Brazilian man with type 2 diabetes mellitus, with nodules on the left ankle [25].…”

“…P. limonesiae grows an indurated painful violet plaque crowned by papules and nodules, as well as ulcers with seropurulent secretion and pimples [25].…”

“…In OA, it reaches 50 mm in diameter, is flat, dusty, with a hazel-colored center, white periphery, and colorless reverse. In MEA, it measures 52 mm in diameter, is flat, radially folded, floccose, dirty white, and saffron colored in the reverse [25].…”

“…Conidiogenic monophialidic, adelophialidic or polyphialidic cells, terminal, lateral, straight to slightly flexuous, cylindrical, 12-33 µm long, 1.5-2.5 µm wide at the base, with evident collarette and characteristic periclinal thickening at conidiogenic site, hyaline, thick and smooth-walled adelophialides of 4.2-20.2 × 1.1-2.2 µm, polyphialides with up to three commonly present conidiogenic loci. Conidia formed in small globose pins at the apex of the phialides, ellipsoidal to cylindrical with rounded, aseptate, hyaline edges [25].…”

“…Phialemoniopsis, especially P. limonesiae sp. nov., has the following antifungal susceptibility (MIC): flucytosine > 64; posaconazole 0.06; voriconazole 0.12; itraconazole 0.06; fluconazole 16; amphotericin B 2 [25].…”