Abstract
Recent studies have changed the taxonomy of Aspergillus section Usti, and a novel species, Aspergillus calidoustus, has been erected. It was also demonstrated that clinical isolates previously identified as A. ustus actually belong to the emerging pathogen A. calidoustus. Aspergillus ustus were frequently isolated from Norwegian water systems, and due to the taxonomical progress, these waterborne strains could be identified more precisely. A MLST study including ITS, calmodulin, β-tubulin and actin sequences was conducted on 32 strains previously identified as A. ustus. All strains were identified as A. calidoustus, which was verified by physiological, biochemical and phylogenetic analyses. This is the first report of that A. calidoustus is able to colonize water distribution systems. In respect to the potential role of water systems as a source of nosocomial infections in patients with immunodeficiency, attention should be given to water systems in hospitals and other healthcare units, especially the heated-water installations.
Acknowledgments
This work was funded by grant NFR/173294 from the Norwegian Research Council.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
This paper was first published online on Early Online on 11 January 2011.