Zhao Ying, Tsang Chi-Ching, Xiao Meng, Chan Jasper F W, Lau Susanna K P, Kong Fanrong, Xu Yingchun, Woo Patrick C Y
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong.
Med Mycol. 2018 Oct 1;56(7):816-827. doi: 10.1093/mmy/myx118.
No study has comprehensively evaluated the performance of 28S nrDNA and ITS sequencing, commercial biochemical test kits, MALDI-TOF MS platforms, and the emerging rep-PCR DNA fingerprinting technology using a cohort of yeast strains collected from a clinical microbiology laboratory. In this study, using 71 clinically important yeast isolates (excluding Candida albicans) collected from a single centre, we determined the concordance of 28S nrDNA and ITS sequencing and evaluated the performance of two commercial test kits, two MALDI-TOF MS platforms, and rep-PCR DNA fingerprinting. 28S nrDNA and ITS sequencing showed complete agreement on the identities of the 71 isolates. Using sequencing results as the standard, 78.9% and 71.8% isolates were correctly identified using the API 20C AUX and Vitek 2 YST ID Card systems, respectively; and 90.1% and 80.3% isolates were correctly identified using the Bruker and Vitek MALDI-TOF MS platforms, respectively. Of the 18 strains belonging to the Candida parapsilosis species complex tested by DiversiLab automated rep-PCR DNA fingerprinting, all were identified only as Candida parapsilosis with similarities ≥93.2%, indicating the misidentification of Candida metapsilosis and Candida orthopsilosis. However, hierarchical cluster analysis of the rep-PCR DNA fingerprints of these three species within this species complex formed three different discrete clusters, indicating that this technology can potentially differentiate the three species. To achieve higher accuracies of identification, the databases of commercial biochemical test kits, MALDI-TOF MS platforms, and DiversiLab automated rep-PCR DNA fingerprinting needs further enrichment, particularly for uncommonly encountered yeast species.
尚无研究使用从临床微生物实验室收集的一组酵母菌株，全面评估28S核糖体DNA（nrDNA）和内转录间隔区（ITS）测序、商业生化检测试剂盒、基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）平台以及新兴的重复序列聚合酶链反应（rep-PCR）DNA指纹技术的性能。在本研究中，我们使用从单一中心收集的71株具有临床重要性的酵母分离株（不包括白色念珠菌），确定了28S nrDNA和ITS测序的一致性，并评估了两种商业检测试剂盒、两个MALDI-TOF MS平台以及rep-PCR DNA指纹技术的性能。28S nrDNA和ITS测序在71株分离株的鉴定上显示出完全一致。以测序结果为标准，使用API 20C AUX和Vitek 2 YST ID卡系统分别正确鉴定了78.9%和71.8%的分离株；使用布鲁克和Vitek MALDI-TOF MS平台分别正确鉴定了90.1%和80.3%的分离株。在通过DiversiLab自动化rep-PCR DNA指纹技术检测的18株近平滑念珠菌复合种菌株中，所有菌株仅被鉴定为近平滑念珠菌，相似度≥93.2%，这表明中间念珠菌和正平滑念珠菌被误鉴定。然而，该复合种内这三个物种的rep-PCR DNA指纹的层次聚类分析形成了三个不同的离散簇，表明该技术有可能区分这三个物种。为了实现更高的鉴定准确性，商业生化检测试剂盒、MALDI-TOF MS平台以及DiversiLab自动化rep-PCR DNA指纹技术的数据库需要进一步充实，特别是对于不常见的酵母物种。
