Bacteria tracking by in vivo magnetic resonance imaging
Bacteria tracking by in vivo magnetic resonance imaging
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DOI：
10.1186/1741-7007-11-63
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发表时间：
2013-05-28
期刊：
影响因子：
5.4
通讯作者：
Faber, Cornelius
中科院分区：
文献类型：
--
作者：
Hoerr, Verena;Tuchscherr, Lorena;Faber, Cornelius
背景资料：在过去的几十年中，已经开发了不同的非侵入性实时成像技术，通过在一段时间内跟踪感染来研究小鼠模型中的细菌致病机制。细菌感染的体内研究以前主要依赖于生物发光成像（BLI），它能够定位代谢活性细菌，但没有提供有关受感染宿主生物体中相关器官状态的数据。在这项研究中，我们建立了一个在体内成像平台，通过磁共振成像（MRI）跟踪细菌在小鼠模型中的感染，以研究感染生物学的临床相关bacteries.Results：我们已经开发出一种方法来标记革兰氏阳性和革兰氏阴性细菌与氧化铁纳米粒子和检测和追求这些与MRI。成功标记的关键步骤是通过产生电感受态细胞来操纵细菌表面电荷，从而使铁颗粒和细胞壁之间发生电荷相互作用。不同的颗粒大小和涂层进行了测试，其能力，附着到细胞壁和可能的标记机制进行了详细说明，通过比较革兰氏阳性和阴性细菌的特性。对于金黄色葡萄球菌，用5 nm柠檬酸盐包被的颗粒实现了0.015 +/-0.002 pg Fe/细菌细胞的铁负载。在皮下和全身感染模型中，铁标记的S。结论：用氧化铁颗粒标记小S.在感染模型中的金黄色葡萄球菌菌落是可行的，通过MRI，并提供了一个通用的工具，以遵循体内细菌感染。建立的细胞标记策略可以很容易地转移到其他细菌物种，从而在分子MRI领域提供了一个概念上的进步。
Background: Different non-invasive real-time imaging techniques have been developed over the last decades to study bacterial pathogenic mechanisms in mouse models by following infections over a time course. In vivo investigations of bacterial infections previously relied mostly on bioluminescence imaging (BLI), which is able to localize metabolically active bacteria, but provides no data on the status of the involved organs in the infected host organism. In this study we established an in vivo imaging platform by magnetic resonance imaging (MRI) for tracking bacteria in mouse models of infection to study infection biology of clinically relevant bacteria.Results: We have developed a method to label Gram-positive and Gram-negative bacteria with iron oxide nano particles and detected and pursued these with MRI. The key step for successful labeling was to manipulate the bacterial surface charge by producing electro-competent cells enabling charge interactions between the iron particles and the cell wall. Different particle sizes and coatings were tested for their ability to attach to the cell wall and possible labeling mechanisms were elaborated by comparing Gram-positive and -negative bacterial characteristics. With 5-nm citrate-coated particles an iron load of 0.015 +/- 0.002 pg Fe/bacterial cell was achieved for Staphylococcus aureus. In both a subcutaneous and a systemic infection model induced by iron-labeled S. aureus bacteria, high resolution MR images allowed for bacterial tracking and provided information on the morphology of organs and the inflammatory response.Conclusion: Labeled with iron oxide particles, in vivo detection of small S. aureus colonies in infection models is feasible by MRI and provides a versatile tool to follow bacterial infections in vivo. The established cell labeling strategy can easily be transferred to other bacterial species and thus provides a conceptual advance in the field of molecular MRI.