Xylohypha emmonsii sp. nov., a new agent of phaeohyphomycosis

Abstract

Xylohypha emmonsii Padhye, McGinnis et Ajello is described as a new dematiaceous opportunistic pathogen of humans and lower animals. This hyphomycete differs from X. bantiana (Saccardo) McGinnis, Padhye, Borelli et Ajello by its inability to grow at 40°C and by the development of short chains of asymmetrically bent to ellipsoid blastoconidia. In brain tissue of mice, experimentally infected with X. emmonsii, the host response to the invading fungus was similar to that observed in mice infected with X. bantiana. In tissues X. bantiana occurred predominantly as long, septate hyphae, in contrast to X. emmonsii, which was more polymorphic.

Subcutaneous phaeohyphomycosis caused by Xylohypha emmonsii

“…5). Both isolates were identified as X. emmonsii (13). The isolates did not liquefy gelatin after 3 weeks of incubation at 25°C but hydrolyzed urea in 7 days.…”

“…The Xylohypha species now known to cause phaeohyphomycosis in humans and lower animals are X. bantiana (11) and X. emmonsii (13). X. bantiana is an important agent of cerebral phaeohyphomycosis.…”

“…Physiologic tests. The urease and proteolytic activities of both isolates were determined by the procedures described by Honbo et al (5) and Padhye et al (13).…”

“…To date, 71 species of dematiaceous fungi, classified in 39 genera, have been described in the literature as etiologic agents of phaeohyphomycosis (2). We describe the first human phaeohyphomycotic infection caused by a newly described species of Xylohypha, namely, Xylohypha emmonsii (13).…”