Liu Runde, Ji Wenxiang, Jiang Min, Shen Jilu
Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei, People's Republic of China; Department of Clinical Laboratory, Anhui Public Health Clinical Center, Hefei, People's Republic of China.
Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei, People's Republic of China; Department of Clinical Laboratory, Anhui Public Health Clinical Center, Hefei, People's Republic of China.
Clin Chim Acta. 2025 Feb 1;567:120106. doi: 10.1016/j.cca.2024.120106. Epub 2024 Dec 21.
Since Candida albicans, a type of fungus, causes severe infections that pose a significant threat to human health, its rapid detection is critical in clinical antifungal therapy. Traditional fungal diagnostic approaches are largely based on the culture method. This method is time-consuming and laborious, taking about 48-72 h, and cannot identify emerging species, making it unsuitable for critically ill patients with bloodstream infections, sepsis, and so on. Other antigen or nucleic acid amplification-based methods were also found to be unsuitable for Point-of-Care Testing (POCT) diagnosis due to various limitations. Therefore, establishing a new approach for the rapid diagnosis of Candida spp is imperative. Herein, we proposed a novel diagnostic method for invasive fungi detection. Specifically, we created a new CRISPR diagnostic platform for Candida albicans-specific Internal Transcriptional Spacer 2 (ITS2) gene by combining the DNase cleavage activity of Cas12a with Recombinase Polymerase Amplification (RPA). Furthermore, to achieve rapid on-site detection under low-resource conditions, we used a transverse lateral flow strip with a single target to visualize the Cas12a single enzyme digestion product. We designated the platform as a rapid molecular detection tool that integrates RPA and the CRISPR-Cas12a technology. The entire platform can accurately identify Candida albicans within 50 minwhile remaining unaffected by other fungi or bacteria. Furthermore, the detection limit of the platform could reach 10 CFU/ml. Moreover, this approach offers additional benefits, including easy operation, low set-up cost, and broad applicability for Candida albicans detection across medical institutions at all levels, especially in township health centers in resource-poor regions.
白色念珠菌是一种真菌,可引发严重感染,对人类健康构成重大威胁,因此其快速检测在临床抗真菌治疗中至关重要。传统的真菌诊断方法主要基于培养法。该方法耗时费力,大约需要48 - 72小时,且无法识别新出现的菌种,不适用于患有血流感染、败血症等的重症患者。由于各种局限性,其他基于抗原或核酸扩增的方法也被发现不适用于即时检测(POCT)诊断。因此,建立一种新的白色念珠菌快速诊断方法势在必行。在此,我们提出了一种用于侵袭性真菌检测的新型诊断方法。具体而言,我们通过将Cas12a的DNase切割活性与重组酶聚合酶扩增(RPA)相结合,创建了一个针对白色念珠菌特异性内部转录间隔区2(ITS2)基因的新型CRISPR诊断平台。此外,为了在资源匮乏的条件下实现快速现场检测,我们使用了带有单一靶点的横向侧流试纸条来可视化Cas12a单酶消化产物。我们将该平台指定为一种集成了RPA和CRISPR - Cas12a技术的快速分子检测工具。整个平台能够在50分钟内准确鉴定白色念珠菌,同时不受其他真菌或细菌的影响。此外,该平台的检测限可达10 CFU/ml。而且,这种方法还有其他优点,包括操作简便、设置成本低,并且对各级医疗机构的白色念珠菌检测具有广泛适用性,尤其适用于资源匮乏地区的乡镇卫生院。