School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, Singapore.
Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, National University Health System, Singapore.
J Med Virol. 2018 Mar;90(3):485-489. doi: 10.1002/jmv.24981. Epub 2017 Nov 14.
The Cepheid Xpert® Norovirus kit automates sample processing, nucleic acid extraction, and real-time reverse transcription polymerase chain reactions (RT-PCRs) to detect norovirus genogroups I (GI) and II (GII). Eighty-five stool samples collected between February 2015 and May 2017 were used to compare the performance of a user-modified Xpert assay against a clinically validated laboratory-developed test (LDT). Of the 85 samples, 54 were previously archived in -80°C freezer. The remaining 31 were fresh samples tested concurrently with the LDT. The results of all samples tested using the Xpert kit and LDT were found to be concordant, including 12 GI- and 42 GII-positive samples, 1 GI and GII coinfection, and 30 negative samples. Comparison of the assays showed perfect concordance with a kappa coefficient score of 1.00 (95%CI from 1.00 to 1.00). Of the 30 negative stool samples tested, three samples were positive for rotavirus detected using an immunochromatographic assay, with no cross-reactivity shown in both LDT and Xpert assays. In-run sample processing control of the Xpert assay for all negative samples tested showed no/minor inhibition. Compared to the LDT, the Xpert assay produced similar or better Ct values for detection. It also showed better mitigation of PCR inhibition in stool sample testing.
Cepheid Xpert® 诺如病毒试剂盒实现了样本处理、核酸提取和实时逆转录聚合酶链反应（RT-PCR）的自动化，可用于检测诺如病毒属 I 型（GI）和 II 型（GII）。我们使用 85 份于 2015 年 2 月至 2017 年 5 月采集的粪便样本，比较用户修改的 Xpert 检测与临床验证的实验室开发检测（LDT）的性能。在这 85 份样本中，54 份为之前保存在-80°C 冰箱中的存档样本，其余 31 份为新鲜样本，与 LDT 同时进行检测。使用 Xpert 试剂盒和 LDT 检测的所有样本结果均一致，包括 12 份 GI 阳性和 42 份 GII 阳性样本、1 份 GI 和 GII 混合感染样本和 30 份阴性样本。两种检测方法的比较显示完全一致，kappa 系数评分为 1.00（95%置信区间为 1.00 到 1.00）。在 30 份阴性粪便样本中，有 3 份使用免疫层析检测呈轮状病毒阳性，LDT 和 Xpert 检测均无交叉反应。对所有阴性样本进行 Xpert 检测时，运行中样本处理控制显示无/轻微抑制。与 LDT 相比，Xpert 检测在检测时产生了相似或更好的 Ct 值，并且在粪便样本检测中对 PCR 抑制的缓解效果更好。
