Aspergillus section Fumigati: antifungal susceptibility patterns and sequence-based identification

This study analyzed 28 Aspergillus strains belonging to the section Fumigati that were isolated from clinical samples in Spain. All isolates sporulated slowly and were unable to grow at 48 degrees C. Phylogenetic analysis based on sequencing of partial sequences of the beta-tubulin and rodlet A genes was used to classify the 28 strains into six different clades (Neosartorya hiratsukae, Neosartorya pseudofischeri, Aspergillus viridinutans, Aspergillus lentulus, Aspergillus fumigatiaffinis, and Aspergillus fumisynnematus). Antifungal susceptibility testing showed heterogeneous patterns and grouped the strains together by species. Most A. lentulus and A. fumigatiaffinis isolates showed high MICs of amphotericin B (geometric mean [GM] MICs, >or=4.5 microg/ml), itraconazole (GM MICs, >or=6 microg/ml), voriconazole (GM MICs, >or=3 microg/ml), and ravuconazole (GM MICs, >or=3 microg/ml); N pseudofischeri and A. viridinutans showed high MICs of itraconazole (GM MICs, >or=8 microg/ml), voriconazole (GM MICs, >or=3.33 microg/ml), and ravuconazole (GM MICs, >or=2 microg/ml); and N. hiratsukae and A. fumisynnematus were susceptible to all the antifungals tested. In conclusion, a number of different species whose morphological features resemble those of Aspergillus fumigatus could succeed in producing invasive infections in the susceptible host. In addition, some of them showed high MICs for most of the antifungals available for the treatment of patients infected with these organisms. The epidemiology and clinical relevance of these species should therefore be addressed.This work was funded in part by grants MPY1175/06 from the Instituto de Salud Carlos III and SAF2005-06541 from the Ministerio de Educacion y Ciencia L. Alcazar-Fuoli held a postdoctoral contract from an EU-STREP project (LSHM-CT-2005-518199). A. Alastruey-Izquierdo held a predoctoral fellowship (grant FI05/00856) from the Fondo de Investigación Sanitaria (FIS, ISCIII).S