Acrophialophora, a poorly known fungus with clinical significance

Area of Science:

• Medical Mycology
• Fungal Taxonomy
• Infectious Diseases

Background:

• Acrophialophora fusispora is an emerging opportunistic fungus implicated in human infections.
• The taxonomic classification of the Acrophialophora genus is currently unresolved.
• Accurate identification of clinical isolates is crucial for effective patient management.

Purpose of the Study:

• To resolve the taxonomy of the Acrophialophora genus using morphological and molecular data.
• To identify and differentiate clinical and environmental Acrophialophora species.
• To evaluate the in vitro antifungal susceptibility profiles of Acrophialophora isolates.

Main Methods:

• Morphological analysis of clinical and environmental Acrophialophora isolates.
• Molecular phylogenetic analyses using nuclear ribosomal DNA (large subunit and internal transcribed spacer regions) and beta-tubulin gene fragments.
• In vitro antifungal susceptibility testing against eight antifungal drugs.

Main Results:

• Phylogenetic analyses placed Acrophialophora within the Chaetomiaceae family.
• Three distinct species were identified: Acrophialophora fusispora, Acrophialophora levis, and Acrophialophora seudatica (formerly Ampullifera).
• Acrophialophora levis (72.7%) and A. fusispora (27.3%) were the predominant species in clinical isolates, primarily from respiratory, subcutaneous, and corneal tissues.
• Voriconazole demonstrated the highest in vitro activity against the tested Acrophialophora isolates, while other agents showed limited efficacy.

Conclusions:

• The study establishes a clear taxonomic framework for the genus Acrophialophora, comprising three species.
• Acrophialophora levis and A. fusispora are significant agents of human infections, particularly affecting the respiratory and superficial tissues.
• Voriconazole is a promising therapeutic option for Acrophialophora infections, warranting further clinical investigation.