Cryptic Aspergillus from clinical samples in the USA and description of a new species in section Flavipedes.

BACKGROUND

In the last few decades there has been an emergence of cryptic Aspergillus as agents of human infections due to the increase in immunocompromised population and to the improvement of identification tools.

METHODS

Continuing our study on Aspergillus isolates from clinical origin deposited in a mycological reference centre in the United States, we selected 37 isolates belonging to less common sections of the genus, to study their species diversity and detect cryptic species by using a polyphasic approach.

RESULTS

From this set of isolates, a total of 16 species were identified; the most frequent being A. calidoustus (48.6%, section Usti), A. terreus (13.5%, section Terrei), and A. nidulans (5.7%, section Nidulantes). The remaining isolates corresponded to 13 species of rare or cryptic Aspergillus, i.e. A. europaeus (section Cremei); A. iizukae, A. micronesiensis, A. spelaeus (section Flavipedes); A. pachycristatus, A. quadrilineatus, A. spinulosporus, A. unguis (section Nidulantes); A. alabamensis, A. carneus, A. hortai (section Terrei), A. granulosus (section Usti); and the new species A. suttoniae (section Flavipedes), which is described here.

CONCLUSIONS

Correct identification of cryptic species is crucial to reveal new potential pathogens, to gather accurate epidemiological data and to choose an appropriate treatment.