Mistaken Identity: Neosartorya pseudofischeri and Its Anamorph Masquerading as Aspergillus fumigatus

• Published in: Journal of Clinical Microbiology 2005-12, Vol.43 (12), p.5996-5999
• Main Authors: Balajee, S. Arunmozhi, Gribskov, Jennifer, Brandt, Mary, Ito, James, Fothergill, Annette, Marr, Kieren A
• Format: Article
• Language: English
• Subjects: Antifungal Agents - pharmacology; Aspergillosis - microbiology; Aspergillus fumigatus; Aspergillus fumigatus - classification; Aspergillus fumigatus - drug effects; Aspergillus fumigatus - genetics; Biological and medical sciences; Diagnostic Errors; DNA, Fungal - analysis; Endocarditis - diagnosis; Endocarditis - microbiology; Eurotiales - classification; Eurotiales - drug effects; Eurotiales - genetics; Eurotiales - isolation & purification; Fundamental and applied biological sciences. Psychology; Humans; Infectious diseases; Lung Diseases, Fungal - diagnosis; Lung Diseases, Fungal - microbiology; Medical sciences; Microbial Sensitivity Tests; Microbiology; Miscellaneous; Mycological Typing Techniques; Mycology; Mycoses - diagnosis; Mycoses - microbiology; Neosartorya; Peritonitis - diagnosis; Peritonitis - microbiology; Phenotype
• ISSN: 0095-1137; 1098-660X; 1098-5530
• DOI: 10.1128/JCM.43.12.5996-5999.2005

Invasive fungal infections caused by Neosartorya pseudofischeri S. W. Peterson [anamorph Aspergillus thermomutatus (Paden) S. W. Peterson] are extremely rare. Phenotypically, the anamorphic state of N. pseudofischeri resembles Aspergillus fumigatus, the predominant agent of invasive aspergillosis in immunocompromised hosts. We report the recovery of three clinical isolates of N. pseudofischeri, all initially misidentified by morphological characteristics as A. fumigatus. All three isolates were correctly identified by sequencing portions of the {szligbeta}-tubulin and the rodlet A genes. Only one of the three isolates produced the confirmatory fruiting bodies and was thus classified as N. pseudofischeri; the other isolates did not produce asci and were therefore identified as A. thermomutatus. All three isolates had higher MICs to voriconazole in vitro compared to A. fumigatus Af293. This report emphasizes that phenotypic identification of filamentous fungi may not identify morphologically similar, but genetically distinct, members of the genus Aspergillus section FUMIGATI: Accurate identification of these organisms may be clinically meaningful, given their potential differences in antifungal susceptibilities.