DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa.
Cepheid, Sunnyvale, CA, USA.
Sci Rep. 2020 Sep 2;10(1):14482. doi: 10.1038/s41598-020-71568-9.
The study describes the novel use of the Xpert MTB/RIF Ultra assay for detection of Mycobacterium tuberculosis complex (MTBC) DNA in samples from white rhinoceros (Ceratotherium simum) and African elephants (Loxodonta africana). Culture negative respiratory sample matrices were spiked to determine if the Ultra could detect MTBC DNA in rhinoceros and elephant samples. Rhinoceros bronchial alveolar lavage fluid (BALF) was found to have an inhibitory effect on the Ultra. In this study, the limit of detection (LOD) of M. tuberculosis H37Rv in all spiked animal samples were 2 CFU/ml compared to 15.6 CFU/ml for humans, while the LOD for M. bovis SB0121 was 30 CFU/ml compared to 143.4 CFU/ml for M. bovis BCG in humans. Screening was performed on stored tissue and respiratory samples from known MTBC-infected animals and MTBC DNA was detected in 92% of samples collected from six rhinoceros and two elephants. Conversely, 83% of culture-negative tissue and respiratory samples from uninfected animals tested negative on the Ultra. In conclusion, the Ultra assay appears to be a sensitive and rapid diagnostic test for the detection of MTBC DNA from tissue and respiratory samples collected from African elephants and rhinoceros. Furthermore, the Ultra assay could provide a new tool for the detection of MTBC in various sample types from other wildlife species.
本研究描述了 Xpert MTB/RIF Ultra 检测试剂盒在检测白犀牛（Ceratotherium simum）和非洲象（Loxodonta africana）样本中的结核分枝杆菌复合群（Mycobacterium tuberculosis complex，MTBC）DNA 的新用途。对培养阴性的呼吸道样本基质进行了加标，以确定 Ultra 是否能够检测到犀牛和大象样本中的 MTBC DNA。结果发现，犀牛支气管肺泡灌洗液（bronchial alveolar lavage fluid，BALF）对 Ultra 有抑制作用。在这项研究中，与人类的检测下限（limit of detection，LOD）相比，M. tuberculosis H37Rv 在所有加标动物样本中的 LOD 为 2 CFU/ml，而 M. bovis SB0121 的 LOD 为 30 CFU/ml。对已知 MTBC 感染动物的储存组织和呼吸道样本进行了筛查，在从六头犀牛和两头大象采集的样本中检测到了 MTBC DNA，阳性率为 92%。相比之下，在未感染动物的培养阴性组织和呼吸道样本中，83%的样本在 Ultra 上呈阴性。总之，Ultra 检测试剂盒似乎是一种敏感、快速的诊断检测方法，可用于检测从非洲象和犀牛采集的组织和呼吸道样本中的 MTBC DNA。此外，Ultra 检测试剂盒可为检测其他野生动物物种各种样本类型中的 MTBC 提供一种新工具。
