Detection of invasive Trichosporon asahii in patient blood by a fungal PCR array

Immunosuppression due to medical therapy has extended life expectancy of patients with previously fatal diseases and is therefore playing a crucial role in the increasing incidence of invasive fungal infections .  Globally, invasive trichosporonosis is reported to be the second most common non-candida yeast infection in patients suffering from haematological malignancies, oftentimes leading to fatal outcomes despite appropriate therapy .

Herein, we report on a retrospectively applied experimental diagnostic fungal PCR-analysis used on an EDTA blood sample and consisting of two pan-fungal reactions and seven branch-specific reactions. Regarding invasive T. asahii infection, this PCR array could considerably shorten time to diagnosis and switch to a targeted therapy with triazoles.

T. asahii morphology on culture, subculture from the positive blood culture bottle:

fig. a) On candida medium biplate after 4 days of incubation. Left side with dry blue/petrol-coloured colonies on chromogenic sabouraud agar, right side with white to cream-coloured colonies with raised surfaces on sabouraud agar. fig. b) Dermasel agar plate after 4 days of incubation showing brilliant-white fluffy growth.

Above fig. represent Binding regions of primers and the probe of the fungal PCR array. ITS: nuclear ribosomal internal transcribed spacer region. The binding region of the probe is marked in orange.

A rapid detection method allowing pathogen identification like the one presented here can be an important addition. By using a method developed for efficient DNA extraction from (filamentous) fungi, an increased specificity of the branch-specific reactions of the fuPCR could shorten time to definitive diagnosis even further and help achieving the best possible outcome.–nk.mailto