Shandong Provincial Hospital for Skin Diseases, Shandong University, Jinan, Shandong, China.
Shandong Provincial Institute of Dermatology and Venereology, Shandong Academy of Medical Sciences, Jinan, Shandong, China.
J Eur Acad Dermatol Venereol. 2018 Jun;32(6):1017-1021. doi: 10.1111/jdv.14843. Epub 2018 Feb 27.
The current gold standard for diagnosing onychomycosis is direct microscopic examination and culturing. Fungal culture is a time-consuming procedure, while direct microscopy of potassium hydroxide (KOH) mounts suffers from low sensitivity. More rapid and sensitive methods for the diagnosis of onychomycosis are in high demand.
To establish an effective method for the diagnosis of onychomycosis by assessing the efficacies of fungal fluorescent staining and internal transcribed spacer (ITS) ribosomal DNA (rDNA) polymerase chain reaction (PCR)-based sequencing.
A total of 204 clinical specimens from patients with suspected onychomycosis were analysed. The gold standard for a true positive sample was positive by KOH, culturing or both methods. All specimens were also tested by fungal fluorescent staining and ITS rDNA PCR-based sequencing. We compared the detection, sensitivity and specificity for these two methods with conventional methods.
In total, 126 (62%) and 102 (50%) were detected by fluorescent staining and PCR-based sequencing, respectively. According to the conventional diagnostic standard, the sensitivity of fluorescent staining and PCR-based sequencing was 97% and 78%, respectively, and specificities of 89% and 90%, respectively. Use of fluorescence enhanced the sensitivity of direct examination by 12% compared with KOH. PCR-based sequencing increased the sensitivity by 6% compared with culturing.
Fluorescence microscopy has a higher sensitivity for the detection of fungi in nail specimens compared with KOH and can be used as a rapid screening tool. PCR-based sequencing was faster and more sensitive compared with culture and when used in conjunction with fluorescence microscopy resulted in higher efficiency.
目前诊断甲真菌病的金标准是直接显微镜检查和培养。真菌培养是一个耗时的过程，而氢氧化钾（KOH）载玻片直接显微镜检查的敏感性较低。因此，人们迫切需要更快速、更敏感的甲真菌病诊断方法。
通过评估真菌荧光染色和内部转录间隔区（ITS）核糖体 DNA（rDNA）聚合酶链反应（PCR）-测序在诊断甲真菌病中的功效，建立一种有效的甲真菌病诊断方法。
分析了 204 例疑似甲真菌病患者的临床标本。阳性 KOH、培养或两种方法均为真阳性样本的金标准。所有标本均采用真菌荧光染色和 ITS rDNA PCR-测序进行检测。我们比较了这两种方法与传统方法的检测、敏感性和特异性。
荧光染色和 PCR-测序分别检测到 126（62%）和 102（50%）例标本。根据传统诊断标准，荧光染色和 PCR-测序的敏感性分别为 97%和 78%，特异性分别为 89%和 90%。与 KOH 相比，荧光染色直接检查的敏感性提高了 12%。与培养相比，PCR-测序提高了 6%的敏感性。
荧光显微镜在检测指甲标本中的真菌方面比 KOH 具有更高的敏感性，可以作为一种快速筛查工具。与培养相比，PCR-测序更快、更敏感，与荧光显微镜结合使用时效率更高。
