A real-time PCR for the detection and characterisation of Aspergillus species.

An early diagnosis of an invasive fungal infection is essential for the initiation of a specific antifungal therapy and to avoid unnecessary discontinuation of a baseline therapy for haematological or oncological diseases. A real-time PCR assay for the detection and strain identification of Aspergillus species from culture strains was evaluated. DNA preparation was evaluated in contaminated culture media, urine and serum. A LightCycler PCR to differentiate various Aspergillus species was established. A real-time PCR assay for the detection of Aspergillus species was improved and was able to detect and differentiate medically important Aspergillus spp. The sensitivity of the test was <10 plasmid equivalents/assay. The real-time PCR assay is a useful tool for the rapid identification of Aspergillus species and might be useful as an early diagnostic tool to detect an invasive fungal infection. A real-time PCR protocol was improved by generating plasmid standards, additional generation of melting curves for species identification and the correlation between the melting temperature and the nucleotide exchanges within the used 18S rRNA gene region.