Development and evaluation of RPA-NFO-LFT and RPA-Cas12a-LFT systems for the detection of Candida albicans

Abstract

Recently, the growing number of medical interventions has led to the risk of invasive candidiasis. Among them, Candida albicans (C. albicans) infection has the highest incidence, which has led to great demand for developing early diagnosis methods. In this study, two lateral flow device based molecular assay systems, RPA-NFO-LFT and RPA-Cas12a-LFT, were established and optimized to achieve the detection of C. albicans. Firstly, efficient and specific primers for C. albicans detection were designed and screened, and the purification of amplification products was also explored. Then, many important conditions and issues for each system were investigated and discussed to improve the performances of the test strip devices in C. albicans detection. An evaluation study revealed that both systems showed favorable specificity and sensitivity in the detection of C. albicans samples with a lower detection limit of 10³ CFU ml⁻¹, while RPA-Cas12a-LFT is more accurate for visual interpretation and more stable toward samples that exhibit serum nucleic acid interference. Finally, the performances of RPA-NFO-LFT and RPA-Cas12a-LFT were compared with that of the conventional qPCR method. This work might provide a reference for the development of molecular assay devices in practical candidiasis diagnosis.