Institute of Fluorescence and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland, USA.
J Clin Microbiol. 2013 Sep;51(9):2913-20. doi: 10.1128/JCM.00980-13. Epub 2013 Jun 26.
Accurate point-of-care (POC) diagnostic tests for Chlamydia trachomatis infection are urgently needed for the rapid treatment of patients. In a blind comparative study, we evaluated microwave-accelerated metal-enhanced fluorescence (MAMEF) assays for ultrafast and sensitive detection of C. trachomatis DNA from vaginal swabs. The results of two distinct MAMEF assays were compared to those of nucleic acid amplification tests (NAATs). The first assay targeted the C. trachomatis 16S rRNA gene, and the second assay targeted the C. trachomatis cryptic plasmid. Using pure C. trachomatis, the MAMEF assays detected as few as 10 inclusion-forming units/ml of C. trachomatis in less than 9 min, including DNA extraction and detection. A total of 257 dry vaginal swabs from 245 female adolescents aged 14 to 22 years were analyzed. Swabs were eluted with water, the solutions were lysed to release and to fragment genomic DNA, and MAMEF-based DNA detection was performed. The prevalence of C. trachomatis by NAATs was 17.5%. Of the 45 samples that were C. trachomatis positive and the 212 samples that were C. trachomatis negative by NAATs, 33/45 and 197/212 were correctly identified by the MAMEF assays if both assays were required to be positive (sensitivity, 73.3%; specificity, 92.9%). Using the plasmid-based assay alone, 37/45 C. trachomatis-positive and 197/212 C. trachomatis-negative samples were detected (sensitivity, 82.2%; specificity, 92.9%). Using the 16S rRNA assay alone, 34/45 C. trachomatis-positive and 197/212 C. trachomatis-negative samples were detected (sensitivity, 75.5%; specificity, 92.9%). The overall rates of agreement with NAAT results for the individual 16S rRNA and cryptic plasmid assays were 89.5% and 91.0%, respectively. Given the sensitivity, specificity, and rapid detection of the plasmid-based assay, the plasmid-based MAMEF assay appears to be suited for clinical POC testing.
迫切需要用于沙眼衣原体感染的准确即时护理（POC）诊断测试，以便快速治疗患者。在一项盲法比较研究中，我们评估了微波加速金属增强荧光（MAMEF）测定法，以从阴道拭子中快速灵敏地检测沙眼衣原体 DNA。将两种不同的 MAMEF 测定法的结果与核酸扩增测试（NAAT）进行了比较。第一个测定法针对沙眼衣原体 16S rRNA 基因，第二个测定法针对沙眼衣原体隐秘质粒。使用纯沙眼衣原体，MAMEF 测定法在不到 9 分钟的时间内检测到低至 10 个包涵体形成单位/ml 的沙眼衣原体，包括 DNA 提取和检测。分析了 245 名 14 至 22 岁的女性青少年的 257 个干燥阴道拭子。拭子用洗脱液洗脱，溶液裂解以释放和片段化基因组 DNA，并进行基于 MAMEF 的 DNA 检测。NAAT 检测到沙眼衣原体的患病率为 17.5%。在 45 个 NAAT 检测沙眼衣原体阳性的样本和 212 个 NAAT 检测沙眼衣原体阴性的样本中，如果两个测定法均为阳性，则 MAMEF 测定法正确识别了 33/45 和 197/212（敏感性，73.3%；特异性，92.9%）。单独使用基于质粒的测定法，检测到 37/45 个沙眼衣原体阳性和 197/212 个沙眼衣原体阴性样本（敏感性，82.2%；特异性，92.9%）。单独使用 16S rRNA 测定法，检测到 34/45 个沙眼衣原体阳性和 197/212 个沙眼衣原体阴性样本（敏感性，75.5%；特异性，92.9%）。单独进行的 16S rRNA 和隐秘质粒测定法与 NAAT 结果的总体符合率分别为 89.5%和 91.0%。鉴于基于质粒的测定法的敏感性、特异性和快速检测，基于质粒的 MAMEF 测定法似乎适合用于临床 POC 检测。
