Canine olfactory detection of a vectored phytobacterial pathogen, Liberibacter asiaticus, and integration with disease control
Canine olfactory detection of a vectored phytobacterial pathogen, Liberibacter asiaticus, and integration with disease control
复制标题
DOI：
10.1073/pnas.1914296117
复制
发表时间：
2020-02-18
影响因子：
11.1
通讯作者：
Schneider, William
中科院分区：
文献类型：
--
作者：
Gottwald, Timothy;Poole, Gavin;Schneider, William
早期发现和快速反应对于避免外来病原体的严重流行至关重要。然而，由于固有的采样问题和实验室吞吐量，大多数检测方法（分子、血清学、化学）在后勤上受到疫情大规模调查的限制。对10只训练有素的犬进行评估，以检测严重的外来植物细菌树栖病原体，亚洲自由候选菌（Candidatus Liberibacter asiaticus, CLas），准确率为0.9905，灵敏度为0.8579，特异性为0.9961。在一项纵向研究中，隐性CLas感染在感染后2周内被检测到，而qPCR的检测时间为1至32个月。当被允许询问多种感染国际柑橘病原体的体内病原体时，犬只对柑橘的利比杆菌病原体有反应，而对其他细菌、病毒或螺旋体病原体没有反应。训练用来检测类感染柑橘的犬类也能检测出类感染的烟草和长春花，携带类的木虱昆虫载体，以及与其他细菌共培养的类感染菌，但类感染菌滴度低于分子检测水平。所有这些观察结果表明，犬科动物可以直接检测到CLas，而不仅仅是由感染产生的宿主挥发物。果园和住宅物业的检测是实时的，类似于每棵树2秒。时空流行病模拟表明，当犬类检测后进行干预（即扑杀受感染个体）时，控制病原体流行是可能的，并且在经济上是可持续的，而目前的分子（qPCR）和视觉检测方法无法抑制感染的指数轨迹。
Early detection and rapid response are crucial to avoid severe epidemics of exotic pathogens. However, most detection methods (molecular, serological, chemical) are logistically limited for large-scale survey of outbreaks due to intrinsic sampling issues and laboratory throughput. Evaluation of 10 canines trained for detection of a severe exotic phytobacterial arboreal pathogen, Candidatus Liberibacter asiaticus (CLas), demonstrated 0.9905 accuracy, 0.8579 sensitivity, and 0.9961 specificity. In a longitudinal study, cryptic CLas infections that remained subclinical visually were detected within 2 wk postinfection compared with 1 to 32 mo for qPCR. When allowed to interrogate a diverse range of in vivo pathogens infecting an international citrus pathogen collection, canines only reacted to Liberibacter pathogens of citrus and not to other bacterial, viral, or spiroplasma pathogens. Canines trained to detect CLas-infected citrus also alerted on CLas-infected tobacco and periwinkle, CLas-bearing psyllid insect vectors, and CLas cocultured with other bacteria but at CLas titers below the level of molecular detection. All of these observations suggest that canines can detect CLas directly rather than only host volatiles produced by the infection. Detection in orchards and residential properties was real time, similar to 2 s per tree. Spatiotemporal epidemic simulations demonstrated that control of pathogen prevalence was possible and economically sustainable when canine detection was followed by intervention (i.e., culling infected individuals), whereas current methods of molecular (qPCR) and visual detection failed to contribute to the suppression of an exponential trajectory of infection.