Reports of cryptic species causing aspergillosis in humans are increasing in the literature. Cryptic species are defined as those which are morphologically indistinguishable, although their identifications can be confirmed using molecular or other techniques which continue to become more widely available in the clinical setting. Antifungal resistance has often been noted in these cases, and indeed there does appear to be a higher prevalence of reduced susceptibility in cryptic species. Many of these observations are published as individual case reports or as a small component of larger data sets, making it challenging to review and compare the data fully. This review article seeks to describe the susceptibility trends and key learning outcomes of specific cases of infections caused by cryptic species, including Aspergillus alliaceus, Aspergillus calidoustus, Aspergillusfelis, Aspergilluslentulus, Aspergillus tubingensis, Aspergillus viridinutans and Neosartorya pseudofischeri. These reports highlight the clinical need for full accurate identification and susceptibility testing to guide patient care.
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Conflict of interest
Susan Howard has received research grants from Astellas, support grants from Gilead, Pfizer and the Fungal Research Trust, travel grants from Astellas and Schering-Plough, equipment grants from the Fungal Research Trust, and has been paid for talks on behalf of Pfizer and Astellas.
Alastruey-Izquierdo A, et al. Population-based survey of filamentous fungi and antifungal resistance in Spain (FILPOP Study). Antimicrob Agents Chemother. 2013;57(7):3380–7.PubMedCentralPubMedCrossRefGoogle Scholar
Balajee SA, et al. Molecular identification of Aspergillus species collected for the Transplant-Associated Infection Surveillance Network. J Clin Microbiol. 2009;47(10):3138–41.PubMedCentralPubMedCrossRefGoogle Scholar
Alcazar-Fuoli L, et al. Aspergillus section Fumigati: antifungal susceptibility patterns and sequence-based identification. Antimicrob Agents Chemother. 2008;52(4):1244–51.PubMedCentralPubMedCrossRefGoogle Scholar
Zbinden A, et al. Fatal outcome after heart transplantation caused by Aspergilluslentulus. Transpl Infect Dis. 2012;14(5):E60–3.PubMedCrossRefGoogle Scholar
Alcazar-Fuoli L, et al. Species identification and antifungal susceptibility patterns of species belonging to Aspergillus section Nigri. Antimicrob Agents Chemother. 2009;53(10):4514–7.PubMedCentralPubMedCrossRefGoogle Scholar
Frisvad JC, et al. Secondary metabolite profiling, growth profiles and other tools for species recognition and important Aspergillus mycotoxins. Stud Mycol. 2007;59:31–7.PubMedCentralPubMedCrossRefGoogle Scholar
Oliveri C, Torta L, Catara V. A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily. Int J Food Microbiol. 2008;127(1–2):147–54.PubMedCrossRefGoogle Scholar
Alastruey-Izquierdo A, et al. In vitro activity of nine antifungal agents against clinical isolates of Aspergilluscalidoustus. Med Mycol. 2010;48(1):97–102.PubMedCrossRefGoogle Scholar
Egli A, et al. Emergence of Aspergilluscalidoustus infection in the era of posttransplantation azole prophylaxis. Transplantation. 2012;94(4):403–10.PubMedCrossRefGoogle Scholar
Pavie J, et al. Breakthrough disseminated Aspergillusustus infection in allogeneic hematopoietic stem cell transplant recipients receiving voriconazole or caspofungin prophylaxis. J Clin Microbiol. 2005;43(9):4902–4.PubMedCentralPubMedCrossRefGoogle Scholar
Balajee SA, et al. Nonsporulating clinical isolate identified as Petromycesalliaceus (anamorph Aspergillusalliaceus) by morphological and sequence-based methods. J Clin Microbiol. 2007;45(8):2701–3.PubMedCentralPubMedCrossRefGoogle Scholar
Ozhak-Baysan B, et al. Aspergillusalliaceus and Aspergillusflavus co-infection in an acute myeloid leukemia patient. Med Mycol. 2010;48(7):995–9.PubMedCrossRefGoogle Scholar
Coelho D, et al. Aspergillusviridinutans: an agent of adult chronic invasive aspergillosis. Med Mycol. 2011;49(7):755–9.PubMedGoogle Scholar
Shigeyasu C, et al. Keratomycosis caused by Aspergillusviridinutans: an Aspergillusfumigatus-resembling mold presenting distinct clinical and antifungal susceptibility patterns. Med Mycol. 2012;50(5):525–8.PubMedCrossRefGoogle Scholar
Pelaez T, et al. Invasive aspergillosis caused by cryptic Aspergillus species: a report of two consecutive episodes in a patient with leukaemia. J Med Microbiol. 2013;62(Pt 3):474–8.PubMedCrossRefGoogle Scholar
Alvarez-Perez S, et al. Polyphasic characterization of fungal isolates from a published case of invasive aspergillosis reveals misidentification of Aspergillusfelis as Aspergillusviridinutans. J Med Microbiol. 2014;63(Pt 4):617–9.PubMedCrossRefGoogle Scholar