Real-time PCR assay to detect DNA in sera for the diagnosis of deep-seated trichosporonosis

Rapid and Simple Detection of Trichosporon asahii by Optimized Colony PCR

Trichosporon asahii is the major pathogen causing invasive trichosporonosis. Conventional methods of its detection are time-consuming or costly and often require complex DNA extraction and purification steps, which hinders rapid clinical diagnosis. In this study, we evaluated colony PCR, which directly uses colonies or trace clinical samples as the template for amplification, for rapid detection of T. asahii infection. Four methods, namely, direct colony, freeze-thaw, glass beads, and enzymolysis, were compared to select the best DNA extraction strategy. We subsequently designed and screened species-specific primers targeting the intergenic spacer 1 (IGS1) of the ribosomal DNA of T. asahii and used them to detect mock infection clinical samples. The species-specific colony PCR based on glass beads proved advantageous, with short procedure time (154.8 ± 0.6 min), good sensitivity (detection limit, 10² CFU/mL), and specificity for T. asahii, indicating that this method can be used for the rapid and simple identification of clinical samples of T. asahii infection.

Quantitative PCR assay used to monitor serum Trichosporon asahii DNA concentrations in disseminated trichosporonosis

A bone marrow transplant recipient with disseminated trichosporonosis was successfully treated with voriconazole. Quantitative PCR assay results for Trichosporon asahii DNA in the sera were well correlated with the patient's clinical course. Based on the in vitro susceptibility test, the organism was susceptible to voriconazole.