Neosartorya udagawae, a heterothallic fungus, has an anamorph that is morphologically indistinguishable from Aspergillus fumigatus. Because of the similarity in their conidial morphology, clinical isolates of N. udagawae are frequently identified as A. fumigatus on phenotypic characteristics alone. We recently documented four cases of invasive aspergillosis caused by N. udagawae in patients with CGD (n=3) and MDS (n=1). In contrast to typical disease caused by A. fumigatus, disease caused by N. udagawae appeared more chronic, with infection spreading across anatomical planes in a contiguous manner. Since N. udagawae is poorly recognized, we characterized the species in comparison with A. fumigatus. A total of 11 N, udagawae strains, including two Type strains and 9 clinical isolates, were compared with A. fumigatus B-5223. The rodA and benA sequence analysis showed the 11N. udagawae strains to be distinct from B-5233. Using PCR, we identified alpha box in CBS114217 and HMG domain in CBSl14218, the two type strains of opposite mating type, indicating that CBSl14217 has MAT1-l locus and CBS114218 has MATI-2. Five of the 9 clinical isolates have MATI-I and 4 have MATl-2 indicating an equal representation of the two mating types as clinical isolates (similar to A. fumigatus), Growth of the N. udagawae strains was considerably slower than A. fumigatus at temperatures between 30Â°-37Â°C. While A, fumigatus grows at 55Â°C but fails to grow at l0Â°C, N. udagawae failed to grow at the temperatures >42Â°C but formed colony at 10Â°CN. udagawae was more susceptible than A. fumigatus to neutrophils as well as hydrogen peroxide and significantly less virulent in CGD mice. Both N. udagawae and A. fumigatus produced gliotoxin. It is plausible that the differences in growth characteristics and susceptibility to host responses is associated with subtle distinction in disease progression in humans.
Full conference title:
17th International Society for Human and Animal Mycology
- ISHAM 17th (2009)