Enhanced performances of the short-PCR coupled lateral flow assay in the detection of Candida albicansin clinical blood samples
Oranee Srichaiyapol,1 Bhanubong Saiboonjan,1 Sawinee Ngernpimai,2 Chonphaksorn Ponsue,3 Nutcha Sa-ingthong,1 Patsara Thongmee,3 Lumyai Wonglakorn,4 Chutipapa Sukkasem,4 Rinjong Promson Kendal,5 Jureerut Daduang,1,3,6 Ratree Tavichakorntrakool,3,6 Arpasiri Srisrattakarn,3,6 Aroonwadee Chanawong,3,6 Molin Wongwattanakul,1,3,6 Aroonlug Lulitanond,3,6 Patcharaporn Tippayawat1,3,6
Affiliations:
1 Center for Innovation and Standard for Medical Technology and Physical Therapy (CISMaP), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
2 Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
3 Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
4 Clinical Microbiology Unit, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
5 Khon Kaen Hospital, Khon Kaen, Thailand
6 Department of Medical Technology, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
Abstract
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.
Objectives: 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.