The Xpert MTB/RIF assay is a molecular assay that has improved the detection of tuberculosis and rifampicin resistance. However, its sensitivity is limited in patients with paucibacillary disease. Xpert MTB/RIF Ultra has been developed to resolve this limitation. We compared the performance of Xpert Ultra with that of culture for detection of Mycobacterium tuberculosis and rifampicin resistance. We reviewed laboratory records for 848 respiratory and 419 extrarespiratory samples that were processed between April 2018 and October 2019. The sensitivity, specificity, negative predictive value, and positive predictive value of Xpert Ultra were 94.8%, 98%, 98.8%, and 91.3% for respiratory samples and 83.8%, 96.9%, 98.4% and 72.1% for nonrespiratory ones. We found 26 culture-negative/Ultra-positive samples. Most of them have low bacillary burden and more than half belonged to patients with history of tuberculosis. Xpert Ultra demonstrates excellent diagnostic accuracy for tuberculosis detection, including paucibacillary specimens. In patients with history of tuberculosis, PCR results should be interpreted carefully.

Xpert MTB / RIF检测是一种分子检测，可改善结核病和利福平耐药性的检测。然而，其敏感性在痤疮杆菌病患者中受到限制。Xpert MTB / RIF Ultra已开发出来，可以解决此限制。我们比较了Xpert Ultra与培养物在结核分枝杆菌检测中的性能和利福平耐药。我们回顾了2018年4月至2019年10月之间处理的848份呼吸和419份呼吸外样品的实验室记录.Xpert Ultra的敏感性，特异性，阴性预测值和阳性预测值分别为94.8％，98％，98.8％和91.3％呼吸样本为83.8％，96.9％，98.4％和72.1％。我们发现了26个培养阴性/超阳性样本。他们大多数具有较低的细菌负担，一半以上属于结核病史患者。Xpert Ultra表现出出色的诊断准确性，可用于结核病检测，包括丘脑标本。在有结核病史的患者中，PCR结果应仔细解释。