Aspergillosis is a clinically important mycosis, and encompasses a wide variety of hronchopulmonary infections. The most causative agents are Aspergillus fumigatus and relatives. Recently molecular phylogenetic analyses based on DNA sequences have promoted a great change in the taxonomy of the species of Aspergillus section Fumigati. Some cryptic species have been proposed as new phylogenetic species, A. lentulus, A. fumigatiaffinis and A. novofumigatus, based on a polyphasic approach that combines morphological, physiologic, and molecular data, A. lentulus was isolated from clinical specimens in the USA, and there are many strains have since been isolated from clinical specimens and soil in various locations. The isolates of A. lentulus and A. udagawae, have ever been identified as A. fumigatus based on morphology, have low in vitro susceptibilities to multiple antifungal drugs, including amphotericin B, voriconazole and Caspofungin. We re-evaluated the identification of the strains identified as A. fumigatus based on morphology preserved at the MMRC, Chiba University, as causative agents of mycosis in human and animals, Most of the examined strains from clinical specimens in Japan were clustered together in the clade including A. fumigatus. The other strains were identified as A. lentulus, A. viridinutans and A. udagawae, We have found no strain included the clade, including A. fumigatiaffinis and A. novofitmigatus. The maximal growth temperatures of are A. fumigatus, A. lentulus and A. udagawae above 50C, 45C and 42C, respectively. These data are useful for classification of those species. Clinical isolates of A. fumigatus are not necessarily morphologically uniform, and mistaken identifications of them by morphological characteristics have often happened. In order to develop rapid identification of A. fumigatus, A. lentulus and A. udagawae, respectively, using PCR and LAMP methods, we newly designed the primer sets.
Full conference title:
17th International Society for Human and Animal Mycology
- ISHAM 17th (2009)