Development of rapid and specific molecular discrimination methods for pathogenic emericella species.

Aspergillosis is an important mycosis caused primarily by Aspergillus fumigatus and its relatives. The genus Emericella is a teleomorph related to the Aspergillus section Nidulantes. The typical anamorphic stage species in this genus is Aspergillus nidulans, which is sometimes a significant agent in chronic granulomatous disease (CGD) patients. The mortality rate of osteomyelitis in CGD patients due to A. nidulans ( E. nidulans ) is very high compared to that due to A. fumigatus. Moreover, two Emericella species ( E. nidulans and E. quadrilineata ) from clinical specimens exhibit different sensitivities against several antifungal drugs. In aspergillosis, correct species identification is important for antifungal therapy. We attempted to develop rapid and specific molecular discrimination by polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) methods in the principal pathogenic Emericella species, and succeeded in establishing species-specific primers corresponding to the hydrophobin gene. These primers discriminate E. nidulans and E. quadrilineata rapidly and specifically. These methods and primers make it possible to diagnose etiological agents in aspergillosis quickly and easily.