Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Jobstmann, M.
Evaluation of new multiplex PCR-based assays for the detection of clinically relevant Candida species.
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2020. pp. 41
[OPEN ACCESS]
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Kessler Harald
- Prattes Jürgen
- Altmetrics:
- Abstract:
- Background: Blood cultures have been considered as diagnostic gold standard for candidemia. Compared to cultures, assays based on polymerase chain reaction (PCR) may be useful to shorten the time to diagnosis of invasive candidiasis and to initiate antifungal therapy. Recently, the new CandID® and CandID PLUS® kits (OLM Diagnostics) for molecular detection of different Candida spp. have been developed. Objectives: The analytical and clinical performance of the new kits was investigated. Reference material and clinical specimens were used. Furthermore, the time-to-result required for the new assays was compared to the current gold standard. Materials and Methods: Nucleic acid extraction was performed on the EMAG® platform. Real-time PCR (qPCR) and detection were performed on the LightCycler® 480 II instrument. The new CandID® and CandID PLUS® kits are based on multiplex qPCR providing detection of three different Candida spp. each and an internal control: Candida albicans, Candida glabrata, Candida parapsilosis with the CandID® and Candida tropicalis, Candida krusei, Candida dubliniensis with the CandID PLUS®. The accuracy of the new kits was determined utilizing the Quality Control for Molecular Diagnostics (QCMD) 2018 Candida spp. EQA Programme. The clinical performance of the new kits was studied with specimens obtained from patients with culture-proven candidemia (n=23; EDTA whole blood samples) and patients with bacteremia but no candidemia (n=31; plasma samples). Results: When the QCMD panel was tested with the new kits, all members were correctly identified with the new PCR assays. Two EDTA whole blood samples obtained from patients with candidemia were found to be inhibited and thus excluded from further analysis. In patients with candidemia, 14 of 21 samples (67%) gave a positive result with all Candida spp. being identified correctly. In patients with bacteremia, 1 of 31 samples gave a positive result with the CandID® assay. Conclusions: Detection of clinically relevant Candida spp. with the CandID® and CandID PLUS® kits shows a comparable specificity but an inferior sensitivity when compared to blood culture. Due to the shorter time to diagnosis, it may be useful as additional diagnostic tool allowing faster diagnosis and quicker start of antifungal therapy.