MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, University of Évora, Mitra, 7006-554 Évora, Portugal; IIFA - Institute for Advanced Studies and Research, University of Évora, Palácio do Vimioso, Largo Marquês de Marialva, 7002 - 554 Évora, Portugal; Conservation Biology Lab, Department of Biology, University of Évora, Évora, Portugal.
Centre for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
Sci Total Environ. 2024 Nov 25;953:176053. doi: 10.1016/j.scitotenv.2024.176053. Epub 2024 Sep 5.
In many Mediterranean ecosystems, animal tuberculosis (TB), caused by Mycobacterium bovis, an ecovar of Mycobacterium tuberculosis complex (MTBC), is maintained by multi-host communities. It is hypothesised that interspecies transmission is mainly indirect via shared contaminated environments. Therefore, identifying spatial areas where MTBC bacteria occur and quantifying space use by susceptible hosts might help predict the spatial likelihood of transmission across the landscape. Here, we aimed to evaluate the transmission risk of MTBC in a multi-host system involving wildlife (ungulates and carnivores) and cattle (Bos taurus). We collected eighty-nine samples from natural substrates (water, soil, and mud) at 38 sampling sites in a TB endemic area within a Mediterranean agroforestry system in Portugal. These samples were analysed by real-time PCR to detect MTBC DNA. Additionally, host-specific space use intensity maps were obtained through camera-trapping covering the same sampling sites. Results evidenced that a significant proportion of samples were positive for MTBC DNA (49 %), suggesting that the contamination is widespread in the area. Moreover, they showed that the probability of MTBC occurrence in the environment was significantly influenced by topographic features (i.e., slope), although other non-significant predictor related with soil conditions (SMI: soil moisture index) incorporated the MTBC contamination model. The integration of host space use intensity maps with the spatial detection of MTBC showed that the red deer (Cervus elaphus) and wild boar (Sus scrofa) exhibited the highest percentages of high-risk areas for MTBC transmission. Furthermore, when considering the co-occurrence of multiple hosts, transmission risk analyses revealed that 26.5 % of the study area represented high-risk conditions for MTBC transmission, mainly in forest areas.
在许多地中海生态系统中，由结核分枝杆菌复合群（MTBC）的牛分枝杆菌生态型引起的动物结核病（TB）通过多宿主群落维持。据推测，种间传播主要是通过共享污染环境间接发生的。因此，确定 MTBC 细菌出现的空间区域并量化易感宿主的空间利用情况，可能有助于预测跨景观传播的空间可能性。在这里，我们旨在评估涉及野生动物（有蹄类动物和食肉动物）和牛（Bos taurus）的多宿主系统中 MTBC 的传播风险。我们从葡萄牙地中海农林系统中一个结核病流行地区的 38 个采样点的天然基质（水、土壤和泥浆）中采集了 89 个样本。通过实时 PCR 分析这些样本以检测 MTBC DNA。此外，还通过覆盖相同采样点的相机陷阱获得了宿主特定的空间利用强度图。结果表明，大量样本 MTBC DNA 呈阳性（49%），表明该地区的污染广泛存在。此外，它们表明环境中 MTBC 发生的概率受到地形特征（即坡度）的显著影响，尽管其他与土壤条件相关的非显著预测因子（SMI：土壤湿度指数）也包含了 MTBC 污染模型。将宿主空间利用强度图与 MTBC 的空间检测相结合表明，马鹿（Cervus elaphus）和野猪（Sus scrofa）的 MTBC 传播高风险区域比例最高。此外，当考虑多个宿主的共存时，传播风险分析表明，研究区域的 26.5%代表 MTBC 传播的高风险条件，主要在森林地区。
