Enhanced performances of the short-PCR coupled lateral flow assay in the detection of Candida albicans in clinical blood samples

BACKGROUND: Candida albicans remains the most common fungal pathogen among the species, causing candidemia. Thus, early diagnosis is indispensable in patients with severe underlying infections. OBJECTIVE: To develop a short-polymerase chain reaction (short-PCR) coupled with lateral flow strip (LFS) assay for the detection of C. albicans in clinical blood samples. METHODS: A short-PCR-LFS was enhanced to detect clinical isolates and clinical blood samples. The ITS2 gene of C. albicans was amplified using the modified primers-probes to produce highly specific, dual-labeled amplicons. The sensitivity and specificity of the test system were evaluated using C. albicans, Candida spp. other than C. albicans and other microbial DNAs. The test system was validated by 44 clinical isolates and 51 clinical blood samples. RESULTS: The short-PCR-LFS revealed a high specificity for C. albicans with no cross-reactivity and a limit of detection (LOD) of 0.1 ng per 2 mL of blood and 2 CFU/mL using a direct colony as a template. The result was consistent with the validation by short-PCR agarose gel electrophoresis (AGE). The short-PCR-LFS assay showed all positives with all C. albicans relevant samples and exhibited negative for other microbial relevance samples. CONCLUSIONS: The entire process of this system provides visual detection results less than 1 h with high sensitivity, high specificity, DNA extraction-free method, and little dependence on instruments. Thus, it can be considered as a promising method for professional use to early detect and identify clinical relevance samples of C. albicans.