Section of Microbiology, Department of Laboratory Medicine, PD Hinduja Hospital and Medical Research Centre, Mumbai, India.
bioMérieux, 3 route de Port Michaud, 38390, La Balme Les Grottes, France.
Eur J Clin Microbiol Infect Dis. 2017 Oct;36(10):1981-1988. doi: 10.1007/s10096-017-3052-2. Epub 2017 Jul 6.
Timely diagnosis of tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is only achieved for ~58% cases. An improved, accurate, time- and cost-effective method for bacteriological confirmation of MTB is necessary. We evaluated Mycotube, a new variant of Lowenstein-Jensen (LJ) culture medium, by comparing it with Mycobacterium Growth Indicator Tube (MGIT) 960 (gold standard), local LJ, and bioMérieux LJ-T in terms of isolation rate and time-to-growth. Pulmonary and extra-pulmonary samples from treatment-naïve suspects (n = 207) were decontaminated by the N-acetyl-L-cysteine-sodium hydroxide method and used to inoculate the four media. Subjective and objective parameters were used for evaluation. Mycotube yielded 140 positive results, compared to 162, 69, and 141 from MGIT, local LJ, and LJ-T, respectively. Of these, 139 (67%) were true-positive results and 1 (0.5%) was false-positive. The mean time-to-growth detection was 17.4 days for Mycotube, compared to 14.5, 28.1, and 16.5 days for MGIT, local LJ, and LJ-T, respectively. The mean time-to-growth for local LJ significantly differed from that for MGIT, but not those for LJ-T and Mycotube. No contamination was observed. Mycotube had a sensitivity of 85.8% and a specificity of 97.8% as compared to MGIT. Mycotube offers good results, comparable with those observed for conventional LJ. It requires only basic laboratory infrastructure. The overall cost of the test should be nearly three times lower than that of MGIT. Mycotube helps with TB diagnosis and generates pure isolates for drug susceptibility testing.
及时诊断结核病（TB），由结核分枝杆菌（MTB）引起，仅能在~58%的病例中实现。因此，我们需要一种改进的、准确的、节省时间和成本的方法，用于 MTB 的细菌学确认。我们通过比较 Mycotube（低氏培养基的一种新变体）与分枝杆菌生长指示管（MGIT）960（金标准）、当地的 LJ 培养基和生物梅里埃 LJ-T 在分离率和生长时间方面，评估了它的性能。我们用 N-乙酰-L-半胱氨酸-氢氧化钠法对 207 例未经治疗的疑似病例的肺和肺外样本进行去污染，并用这四种培养基进行接种。采用主观和客观参数进行评估。Mycotube 得到了 140 个阳性结果，而 MGIT、当地 LJ 和 LJ-T 分别得到了 162、69 和 141 个阳性结果。其中，139 个（67%）是真正的阳性结果，1 个（0.5%）是假阳性。Mycotube 的平均生长检测时间为 17.4 天，而 MGIT、当地 LJ 和 LJ-T 的平均生长检测时间分别为 14.5、28.1 和 16.5 天。当地 LJ 的平均生长检测时间明显不同于 MGIT，但与 LJ-T 无差异。未观察到污染。Mycotube 的敏感性为 85.8%，特异性为 97.8%，与 MGIT 相比。Mycotube 提供了良好的结果，与传统 LJ 的结果相当。它只需要基本的实验室基础设施。该测试的总费用应该比 MGIT 低近三倍。Mycotube 有助于结核病的诊断，并生成用于药敏试验的纯分离株。
