Using a multi-host bacterial pathogen to understand host-specific adaptation and virulence

了解细菌病原体的宿主范围和毒力对于我们预测和控制新发和再发传染病的能力至关重要。 对于已经进化出利用植物和动物的能力的多宿主病原体，了解其宿主范围和疾病策略对于评估其进化动力和出现潜力至关重要。 这项工作将涉及成团泛菌的临床和植物致病菌株的系统发育分析，以确定这些菌株是否密切相关或形成不同的进化组。 在植物和动物宿主中测试它们的致病性将揭示它们的真实宿主范围，以及植物分离物是否具有感染动物的能力。 这将辅之以遗传筛选，以确定动物特异性毒力因子，然后可用于确定特定菌株是否有可能成为动物致病菌。 多个聚团青霉分离株的全基因组比较沿着所有分离株的毒力基因分布分析将允许重建使该细菌物种利用植物和动物宿主的逐步进化事件。 成团疫霉作为一种遗传多样的多寄主病原菌，不仅为研究其寄主特异性毒力决定因子提供了独特的机会，而且也为研究其寄主范围的扩大和缩小提供了进化动力。 这项研究有可能从根本上改变我们对宿主特异性毒力和疾病以及新感染因子出现的进化过程的理解。

Understanding the host range and virulence of bacterial pathogens is central to our ability to predict and control emerging and reemerging infectious diseases. For multi-host pathogens, which have evolved the ability to exploit both plants and animals, knowledge of their host range and disease strategies is critical to assessing their evolutionary momentum and potential for emergence. This work will involve a phylogenetic analysis of clinical and plant pathogenic isolates of Pantoea agglomerans to determine whether these isolates are closely related or form distinct evolutionary groups. Testing their pathogenicity in both plant and animal hosts will reveal their true host range, and whether plant isolates have the capacity to infect animals. This will be complemented by genetic screening to identify animal-specific virulence factors, which can then be used to identify whether a specific strain has the potential to become animal-pathogenic. Whole-genome comparisons of multiple P. agglomerans isolates along with an analysis of virulence gene distribution across all isolates will permit the reconstruction of the stepwise evolutionary events that have allowed this bacterial species to exploit both plant and animal hosts. As a genetically diverse multi-host pathogen, P. agglomerans not only provides the unique opportunity to study host-specific virulence determinants, but also the evolutionary forces contributing to the expansion and retraction of host range. This research has the potential to fundamentally alter our understanding of the evolutionary processes that govern host-specific virulence and disease, and the emergence of new infectious agents.