This study aimed at evaluating performance of Xpert MTB/RIF (Xpert) regarding detection of pulmonary tuberculosis compared to acid-fast bacilli (AFB) smear and culture, and concordance of rifampin resistance with drug susceptibility test. Specimens simultaneously referred for AFB smear, culture, and Xpert during April 2015 to March 2018 were retrospectively reviewed. Sensitivity, specificity, and mean cycle-threshold (C_t) values of Xpert and rifampin resistance results were analyzed. Results of Xpert for pulmonary tuberculosis were evaluated by AFB smear grade. Among the total of 3,840 specimens, 491 were positive in Xpert and 626 were positive in culture. Sensitivity and specificity of Xpert was 75.6% and 99.4%, respectively. Sensitivity of Xpert in smear-positive/culture-positive specimens was 98.6% and those of smear-negative and trace/culture-positive was 63.1%. Positivity of Xpert in culture-positive specimens were 89.9%/98.6%/95.7%/100.0%/100.0% in smear grade trace/1+/2+/3+/4+. Ct values of 491 specimens significantly lowered as AFB smear grade increased (p<0.0001). C_t of smear-positive/smear-trace/smear-negative specimens were 21.7 ± 4.2/26.5 ± 3.9/27.4 ± 3.6, respectively. Rifampin resistance tested by Xpert and culture was 98.3% concordant. Region covered by probe E was the most frequently mutated (50.0%). Xpert showed reliable performance in detecting pulmonary tuberculosis in smear-positive/culture-positive specimens and further improvements are needed for smear negative/culture positive specimens.

本研究旨在评估 Xpert MTB/RIF (Xpert) 与抗酸杆菌 (AFB) 涂片和培养相比检测肺结核的性能，以及利福平耐药性与药敏试验的一致性。对 2015 年 4 月至 2018 年 3 月期间同时进行 AFB 涂片、培养和 Xpert 的标本进行了回顾性审查。敏感性、特异性和平均循环阈值 (C _t) 分析了 Xpert 和利福平耐药结果的值。Xpert 对肺结核的结果通过 AFB 涂片分级进行评估。在总共 3,840 份标本中，491 份 Xpert 阳性，626 份培养阳性。Xpert 的灵敏度和特异性分别为 75.6% 和 99.4%。Xpert 在涂片阳性/培养阳性标本中的灵敏度为 98.6%，涂片阴性和痕量/培养阳性标本的灵敏度为 63.1%。Xpert 在培养阳性标本中的阳性率为 89.9%/98.6%/95.7%/100.0%/100.0%，涂片级痕量/1+/2+/3+/4+。随着 AFB 涂片等级的增加，491 个标本的 Ct 值显着降低 ( p <0.0001)。ç _Ť涂片阳性/涂片痕量/涂片阴性标本分别为 21.7 ± 4.2/26.5 ± 3.9/27.4 ± 3.6。Xpert 和培养测试的利福平耐药性是 98.3% 一致的。探针 E 覆盖的区域突变最频繁 (50.0%)。Xpert 在检测涂片阳性/培养阳性标本中的肺结核方面表现出可靠的性能，对于涂片阴性/培养阳性标本需要进一步改进。