Pathogenesis and Control of Chronic Infections, INSERM, EFS, Université de Montpellier, CHU de Montpellier, France.
UMR MIVEGEC IRD-CNRS-Université de Montpellier, centre IRD, Montpellier, CHU Montpellier, Montpellier, France.
Diagn Microbiol Infect Dis. 2019 Aug;94(4):365-370. doi: 10.1016/j.diagmicrobio.2019.02.008. Epub 2019 Feb 21.
The Xpert MTB/RIF Ultra assay has recently been launched to improve the detection of smear negative disease. This retrospective study compares the sensitivity of Xpert MTB/RIF Ultra with that of Xpert MTB/RIF tests and IS6110 real-time PCR in sputum. Diagnostic performance of three molecular tests was evaluated using 48 culture-positive clinical respiratory specimens diluted to obtain paucibacillary sputum specimens. Xpert MTB/RIF Ultra had the highest sensitivity of 100% compared to 42% (P < 0.001) for Xpert MTB/RIF and 64.5% (P = 0.02) for IS6110-PCR. All "very low" or "low" positive specimens using Xpert MTB/RIF Ultra were tested positive using IS6110-PCR, but 35.4% were found negative using Xpert MTB/RIF. Xpert MTB/RIF Ultra is more sensitive than the two other tests for sputum with a low bacterial load. Adding detection of IS6110 and IS1081 to rpoB, is a key evolution of the assay and improves the detection of Mycobacterium tuberculosis' DNA in paucibacillary sputum.
Xpert MTB/RIF Ultra assay 最近推出，旨在提高对涂片阴性疾病的检测。这项回顾性研究比较了 Xpert MTB/RIF Ultra 与 Xpert MTB/RIF 检测和 IS6110 实时 PCR 在痰中的敏感性。使用 48 份培养阳性的临床呼吸道标本进行稀释，以获得少量痰标本，评估了三种分子检测的诊断性能。与 Xpert MTB/RIF（42%）相比，Xpert MTB/RIF Ultra 的敏感性最高，为 100%（P < 0.001），与 IS6110-PCR 的敏感性为 64.5%（P = 0.02）。所有使用 Xpert MTB/RIF Ultra 检测为“非常低”或“低”阳性的标本均使用 IS6110-PCR 检测为阳性，但使用 Xpert MTB/RIF 检测有 35.4%为阴性。Xpert MTB/RIF Ultra 比其他两种检测方法对低细菌负荷的痰标本更敏感。在 rpoB 中添加 IS6110 和 IS1081 的检测是该检测方法的关键演进，提高了对少菌痰中结核分枝杆菌 DNA 的检测。
