Aspergillus section Fumigati typing by PCR-restriction fragment polymorphism

Area of Science:

• Medical Mycology
• Molecular Biology
• Clinical Microbiology

Background:

• Several Aspergillus section Fumigati species, including Aspergillus fumigatus, A. lentulus, and Neosartorya udagawae, are morphologically similar.
• Accurate identification is clinically important due to varying antifungal susceptibilities among these species.
• Previous work established A. lentulus as distinct from A. fumigatus using multilocus sequence typing.

Purpose of the Study:

• To develop a rapid and accurate molecular method for distinguishing key Aspergillus section Fumigati species.
• To differentiate between Aspergillus fumigatus, A. lentulus, and N. udagawae based on genetic markers.

Main Methods:

• Utilized multilocus sequence typing data, specifically focusing on the beta-tubulin (benA) gene.
• Developed a PCR-restriction fragment length polymorphism (PCR-RFLP) assay targeting polymorphic intronic regions of the benA gene.
• Validated the PCR-RFLP method using clinical isolates and in silico analysis of Aspergillus spp. sequences from GenBank.

Main Results:

• The benA gene exhibits high interspecies variability in intronic regions, conserved within species.
• Digestion of the benA amplicon with BccI restriction enzyme produced unique banding patterns for each target species.
• The PCR-RFLP method demonstrated high accuracy in distinguishing A. fumigatus, A. lentulus, and N. udagawae.

Conclusions:

• PCR-RFLP of the benA gene provides a simple, rapid, and accurate method for identifying clinically relevant, morphologically similar Aspergillus species.
• This molecular technique aids in the correct identification of disease-causing Aspergillus spp. within the Fumigati section.
• Facilitates appropriate antifungal treatment selection by enabling precise species identification.