DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
South African National Parks, Veterinary Wildlife Services, Kruger National Park, Skukuza, South Africa.
Front Immunol. 2023 Sep 1;14:1216262. doi: 10.3389/fimmu.2023.1216262. eCollection 2023.
() is the causative agent of animal tuberculosis (TB) which poses a threat to many of South Africa's most iconic wildlife species, including leopards (). Due to limited tests for wildlife, the development of accurate ante-mortem tests for TB diagnosis in African big cat populations is urgently required. The aim of this study was to evaluate currently available immunological assays for their ability to detect infection in leopards.
Leopard whole blood (n=19) was stimulated using the QuantiFERON Gold Plus In-Tube System (QFT) to evaluate cytokine gene expression and protein production, along with serological assays. The GeneXpert MTB/RIF Ultra (GXU) qPCR assay, mycobacterial culture, and speciation by genomic regions of difference PCR, was used to confirm infection in leopards.
infection was confirmed in six leopards and individuals that were tuberculin skin test (TST) negative were used for comparison. The GXU assay was positive using all available tissue homogenates (n=5) from culture positive animals. culture-confirmed leopards had greater antigen-specific responses, in the QFT interferon gamma release assay, and gene expression assays, compared to TST-negative individuals. One culture-confirmed leopard had detectable antibodies using the DPP Vet TB assay.
Preliminary results demonstrated that immunoassays and TST may be potential tools to identify -infected leopards. The GXU assay provided rapid direct detection of infected leopards. Further studies should aim to improve TB diagnosis in wild felids, which will facilitate disease surveillance and screening.
（）是动物结核病（TB）的病原体，对南非许多标志性的野生动物物种构成威胁，包括豹子（）。由于对野生动物的检测有限，迫切需要开发用于非洲大型猫科动物种群中 TB 诊断的准确生前检测方法。本研究的目的是评估当前可用的免疫测定法检测豹子中（）感染的能力。
使用 QuantiFERON Gold Plus In-Tube 系统（QFT）刺激豹子全血（n=19），以评估细胞因子基因表达和蛋白产生，以及血清学检测。GeneXpert MTB/RIF Ultra（GXU）qPCR 检测、分枝杆菌培养和基于基因组差异区域 PCR 的种系鉴定用于确认豹子中的（）感染。
在六只豹子中确认了（）感染，并用结核菌素皮肤试验（TST）阴性的个体进行了比较。GXU 检测法对所有来自培养阳性动物的组织匀浆（n=5）均呈阳性。与 TST 阴性个体相比，QFT 干扰素释放测定和（）基因表达测定中的抗原特异性反应在培养物确认的豹子中更大。一只培养物确认的豹子使用 DPP Vet TB 检测法可检测到抗体。
初步结果表明，免疫测定法和 TST 可能是识别（）感染豹子的潜在工具。GXU 检测法可快速直接检测感染的豹子。进一步的研究应旨在改善野生猫科动物的 TB 诊断，这将有助于疾病监测和筛查。
