Kizny Gordon Alice, McIver Christopher, Kim Minhee, Murrell Dedee F, Taylor Peter
Department of Microbiology, South Eastern Area Laboratory Services, St George Hospital, Sydney, Australia.
Department of Microbiology, South Eastern Area Laboratory Services, St George Hospital, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney, Australia.
Pathology. 2016 Dec;48(7):720-726. doi: 10.1016/j.pathol.2016.08.006. Epub 2016 Oct 22.
The dermatophytoses are the most common superficial fungal infections worldwide. Clinical diagnosis is not reliable as there are many differentials, and laboratory diagnosis is required to gain access to treatment in more severe disease. Traditional diagnostic methods are limited by suboptimal sensitivity, specificity and prolonged turnaround times. Molecular methods are being used increasingly in the diagnostic algorithm in the clinical microbiology laboratory. The aim of this study was to evaluate a real-time polymerase chain reaction (RT-PCR) targeting the chitin synthase 1 gene (CHS1) of dermatophytes for analytical specificity, and to assess its clinical application by comparing it to the current methods of microscopy and culture. We also assessed a novel non-invasive sample collection technique involving adhesive tape impressions of suspected lesions. The PCR was highly specific, being able to discern between cultures of dermatophytes and other microorganisms. It also proved to be more sensitive than traditional methods at detecting dermatophytes in clinical samples. Similar sensitivities were seen on the samples assessed by the adhesive tape technique. An internal control system allowed for the detection of inhibition in certain culture and clinical specimens. This rapid and cost-effective technique could be incorporated into the initial diagnostic algorithm for dermatophytosis in Australian laboratories.
皮肤癣菌病是全球最常见的浅表真菌感染。由于存在多种鉴别诊断，临床诊断不可靠，在病情较严重时需要实验室诊断才能进行治疗。传统诊断方法存在敏感性欠佳、特异性不足和周转时间长的局限。分子方法在临床微生物实验室的诊断流程中使用得越来越多。本研究的目的是评估针对皮肤癣菌几丁质合酶1基因（CHS1）的实时聚合酶链反应（RT-PCR）的分析特异性，并通过与当前的显微镜检查和培养方法进行比较来评估其临床应用。我们还评估了一种新型非侵入性样本采集技术，即对疑似病变部位进行胶带印片。该PCR具有高度特异性，能够区分皮肤癣菌培养物和其他微生物。在检测临床样本中的皮肤癣菌方面，它也比传统方法更敏感。通过胶带技术评估的样本显示出相似的敏感性。一个内部对照系统可检测某些培养物和临床标本中的抑制作用。这种快速且经济高效的技术可纳入澳大利亚实验室皮肤癣菌病的初始诊断流程。
