Evaluation of PCR-reverse line blot hybridization assay for simultaneous identification of medically important...

In immunocompromised patients suffering from invasive fungal infections, rapid identification of fungal species is important since the appropriate treatment is usually related to the responsible species. We describe here, an assay based on combination of PCR and reverse line blot hybridization (PCR/RLB) for differentiation causative agent of fungal infections.

We performed PCR/RLB assay on 10 reference strains, which include Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, and A. clavatus), Mucor circnelloides, Rhizopus oryzae, Alternaria alternata, Cladosporium herbarum, and Fusarium solani. Besides, twenty-two clinical specimens from patients with proven fungal infections were analyzed for the identification of species. The obtained results were then compared with the results of culture and sequence analysis.

The fungal species-specific oligonucleotide probes were able to distinguish between all species represented in this study with the exception of cross-reactivity between A. niger and A. fumigatus species. Two specimens, which were represented as mixed fungi in culture, were identified properly by this method. Results of the RLB assay were concordant with the culture and ITS sequencing results.

Our result demonstrate that the RLB assay potentially is suitable for rapid and simultaneous identification of variety fungal pathogens directly from culture as well as from clinical specimens.