de Haas Petra, Yenew Bazezew, Mengesha Endale, Slyzkyi Andrii, Gashu Zewdu, Lounnas Manon, Tesfaye Ephrem, Bedru Ahmed, Tiemersma Edine, Kremer Kristin, Amare Misikir, Diriba Getu, Zerihun Betselot, Gudina Tilaye, Tegegn Ben, Bonnet Maryline, Negeri Challa, Klinkenberg Eveline
KNCV Tuberculosis Foundation, The Hague, The Netherlands.
Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
J Clin Microbiol. 2021 Jul 19;59(8):e0040621. doi: 10.1128/JCM.00406-21.
Young children cannot easily produce sputum for diagnosis of pulmonary tuberculosis (TB). Alternatively, Mycobacterium tuberculosis complex bacilli can be detected in stool by using the Xpert MTB/RIF (Ultra) assay (Xpert). Published stool processing methods contain somewhat complex procedures and require additional supplies. The aim of this study was to develop a simple one-step (SOS) stool processing method based on gravity sedimentation only, similar to Xpert testing of sputum samples, for the detection of M. tuberculosis in stool samples. We first assessed whether the SOS stool method could provide valid Xpert results without the need for bead-beating, dilution, and filtration steps. We concluded that this was the case, and we then validated the SOS stool method by testing spiked stool samples. By using the SOS stool method, 27 of the 29 spiked samples gave valid Xpert results, and M. tuberculosis was recovered from all 27 samples. The proof of principle of the SOS stool method was demonstrated in routine settings in Addis Ababa, Ethiopia. Nine of 123 children with presumptive TB had M. tuberculosis-positive results for nasogastric aspiration (NGA) samples, and 7 (77.8%) of those children also had M. tuberculosis-positive Xpert results for stool samples. Additionally, M. tuberculosis was detected in the stool samples but not the NGA samples from 2 children. The SOS stool processing method makes use of the standard Xpert assay kit, without the need for additional supplies or equipment. The method can potentially be rolled out to any Xpert site, bringing a bacteriologically confirmed diagnosis of TB in children closer to the point of care.
幼儿难以咳出痰液用于肺结核（TB）诊断。另外，可通过使用Xpert MTB/RIF（Ultra）检测法（Xpert）在粪便中检测结核分枝杆菌复合群杆菌。已发表的粪便处理方法包含一些复杂的程序，且需要额外的耗材。本研究的目的是开发一种仅基于重力沉降的简单一步法（SOS）粪便处理方法，类似于痰液样本的Xpert检测，用于检测粪便样本中的结核分枝杆菌。我们首先评估了SOS粪便方法是否无需珠磨、稀释和过滤步骤就能提供有效的Xpert检测结果。我们得出结论，情况确实如此，然后通过检测加标粪便样本对SOS粪便方法进行了验证。使用SOS粪便方法，29个加标样本中有27个给出了有效的Xpert检测结果，并且从所有27个样本中都分离出了结核分枝杆菌。SOS粪便方法的原理验证在埃塞俄比亚亚的斯亚贝巴的常规环境中得到了证实。123名疑似结核病儿童中有9名的鼻胃抽吸（NGA）样本结核分枝杆菌检测呈阳性，其中7名（77.8%）儿童的粪便样本Xpert检测也呈结核分枝杆菌阳性。此外，在2名儿童的粪便样本中检测到了结核分枝杆菌，但在NGA样本中未检测到。SOS粪便处理方法使用标准Xpert检测试剂盒,无需额外的耗材或设备。该方法有可能推广到任何配备Xpert的检测点，使儿童结核病的细菌学确诊更接近医疗点。
