Cryptic and Rare AspergillusSpecies in Brazil: Prevalence in Clinical Samples and In VitroSusceptibility to Triazoles

ABSTRACTAspergillusspp. are among the most common causes of opportunistic invasive fungal infections in tertiary care hospitals. Little is known about the prevalence and in vitrosusceptibility of Aspergillusspecies in Latin America, because there are few medical centers able to perform accurate identification at the species level. The purpose of this study was to analyze the distribution of cryptic and rare Aspergillusspecies among clinical samples from 133 patients with suspected aspergillosis admitted in 12 medical centers in Brazil and to analyze the in vitroactivity of different antifungal drugs. The identification of Aspergillusspecies was performed based on a polyphasic approach, as well as sequencing analysis of the internal transcribed spacer (ITS) region, calmodulin, and ß-tubulin genes and phylogenetic analysis when necessary. The in vitrosusceptibility tests with voriconazole, posaconazole, and itraconazole were performed according to the CLSI M38-A2 document (2008). We demonstrated a high prevalence of cryptic species causing human infection. Only three isolates, representing the species Aspergillus thermomutatus, A. ochraceus, and A. calidoustus, showed less in vitrosusceptibility to at least one of the triazoles tested. Accurate identifications of Aspergillusat the species level and with in vitrosusceptibility tests are important because some species may present unique resistance patterns against specific antifungal drugs.