Open AccessCryptic aspergillosis: a rare entity and a diagnostic challenge
Author(s) -
R. Lavanya,
Marilyn M. Ninan,
Regi Kurien,
Fouzia N. A,
Rani Diana Sahni,
Joy S. Michael
Publication year - 2022
Publication title -
access microbiology
Language(s) - English
Resource type - Journals
ISSN - 2516-8290
DOI - 10.1099/acmi.0.000344
Subject(s) - aspergillus , internal transcribed spacer , aspergillosis , species complex , biology , microbiology and biotechnology , aspergillus fumigatus , identification (biology) , ribosomal rna , genetics , gene , immunology , ecology , phylogenetic tree
Introduction. Cryptic aspergillosis, caused by cryptic species of Aspergillus , is increasingly reported in humans and causes significant morbidity and mortality in immunocompromised individuals. The main aim of this study was to describe the occurrence of this entity at a large tertiary care centre and analyse the challenges in identifying them in a routine diagnostic laboratory. Methods. This was a retrospective case review of all patients diagnosed with cryptic Aspergillus species from April 2019 to February 2020. The isolates were identified using conventional microbiological techniques, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI- TOF MS), 28S rRNA and internal transcribed spacer (ITS) sequencing. Results. The species identified were Aspergillus tamarii, Aspergillus lentulus and Aspergillus sydowii . Identification by MALDI- TOF MS and sequencing was concordant for all except A. sydowii , with MALDI- TOF MS misidentifying it as Aspergillus thermomutans . All isolates showed low minimum inhibitory concentrations (MICs) for the panel of antifungal drugs. Conclusion. Aspergillosis caused by cryptic Aspergillus species presents a diagnostic challenge. This study confirms the importance of molecular methods for accurate identification.