Department of Clinical Laboratory, Peking University Shougang Hospital, Beijing, China.
Department of Pathogen Biology, School of Basic Medicine and Lifescience, Hainan Medical University, Haikou, China.
Front Cell Infect Microbiol. 2019 Apr 16;9:102. doi: 10.3389/fcimb.2019.00102. eCollection 2019.
is an opportunistic pathogenic yeast that predominantly causes invasive candidiasis. The conventional diagnosis of infection depends on time-consuming, culture-based gold-standard methods. Here, a multiple cross displacement amplification (MCDA) assay, combined with a gold nanoparticle-based lateral flow biosensor (LFB) visualization method, was developed for the rapid detection of . The internal transcribed spacer II, a region between 5.8 and 28 S fungal ribosomal DNA, is a species-specific sequence that was used as the MCDA assay target. As an isothermal amplification method, the MCDA reaction with optimized conditions could be completed within only 40 min at a constant temperature (64°C). Then, the amplification reaction products could be visibly detected by a LFB without special equipment. The developed MCDA-LFB assay for detection was a specific and accurate method, and could distinguish from other pathogens. Just 200 fg of genomic DNA template from pure cultures of could be detected using the MCDA-LFB method. The limit of detection (LOD) of the new method was more sensitive than that of both qPCR and loop-mediated isothermal amplification (LAMP). Of 240 clinical sputum samples, all of the -positive (87/240) samples identified by the gold-standard method were successfully detected by the MCDA-LFB assay. Moreover, the true positive rate of the newly developed assay was not only higher than that of qPCR (100 vs. 86.2%), but also higher than that of LAMP (100 vs. 94.3%). Thus, the MCDA-LFB assay might be a simple, specific, and sensitive method for the rapid diagnosis of in clinical samples.
是一种机会致病性酵母,主要引起侵袭性念珠菌病。感染的传统诊断依赖于耗时的、基于培养的金标准方法。在这里,开发了一种多重交叉置换扩增(MCDA)检测方法,结合基于金纳米粒子的侧流生物传感器(LFB)可视化方法,用于快速检测。内部转录间隔区 II,位于 5.8 和 28 S 真菌核糖体 DNA 之间的一个区域,是一个种特异性序列,被用作 MCDA 检测方法的靶标。作为一种等温扩增方法,优化条件下的 MCDA 反应仅在恒定温度(64°C)下 40 分钟内即可完成。然后,扩增反应产物可以通过 LFB 进行可视化检测,无需特殊设备。用于 检测的开发的 MCDA-LFB 检测方法是一种特异性和准确性方法,可以区分 与其他病原体。仅使用 MCDA-LFB 方法即可从纯培养物中检测到 200 fg 的基因组 DNA 模板。与 qPCR 和环介导等温扩增(LAMP)相比,新方法的检测限(LOD)更灵敏。在 240 份临床痰样本中,金标准方法鉴定的所有 阳性(87/240)样本均被 MCDA-LFB 检测方法成功检测到。此外,新开发的检测方法的真阳性率不仅高于 qPCR(100%比 86.2%),而且高于 LAMP(100%比 94.3%)。因此,MCDA-LFB 检测方法可能是一种用于快速诊断临床样本中 的简单、特异和敏感的方法。