Molecular screening of 246 Portuguese Aspergillus isolates among different clinical and environmental sources

This article was awarded the Young Investigator Prize, 6th Trends in Medical Mycology, Copenhagen, 2013.Clinical and environmental samples from Portugal were screened for the presence of Aspergillus and the distribution of the different species-complexes determined to understand differences in their distribution from different sources. Fifty-seven Aspergillus isolates from clinical samples were collected from 10 health institutions. Six species-complexes were detected by ITS sequencing: Fumigati, Flavi, and Nigri were the most frequent (50.9%, 21.0% and 15.8%, respectively). β-tubulin and calmodulin sequencing resulted in seven cryptic species (A. awamorii, A. brasiliensis, A. fructus, A. lentulus, A. sydowii, A. tubigensis, and Emmericella echinulata) being identified among the 57 isolates. Thirty-nine isolates of Aspergillus were recovered from beach sand and poultries, 31 from swineries, and 80 from hospital environments, for a total 189 isolates. Eleven species-complexes were found in these 189 isolates, and those belonging to the Versicolores species-complex were found the most frequently (23.8%). There was a significant association between the different environmental sources and the distribution of the several species-complexes; the hospital environment had greater variability of species-complexes than other environmental locations. A high prevalence of cryptic species within Circumdati complex was detected in several environments and from the isolates analyzed, at least four cryptic species were identified, most of them growing at 37ºC. Because Aspergillus species-complexes have different susceptibilities to antifungals, knowing the species-complex epidemiology for each setting, as well as the identification of cryptic species among the collected clinical isolates is important. This may allow preventive or corrective measures to be taken, which may result in decreased exposure to those organisms and a better prognosis.R. S. was financially supported by a fellowship from Fundação para a Ciência e Tecnologia Portugal (contract SFRH/BPD/72775/2010)