Departamento de Química en Ciencias Farmacéuticas. Universidad Complutense de Madrid, Madrid, Spain.
CIBERINFEC-CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain.
Microbiol Spectr. 2023 Jun 15;11(3):e0454022. doi: 10.1128/spectrum.04540-22. Epub 2023 Apr 3.
Osteomyelitis is an infection of the bone, associated with an inflammatory process. Imaging plays an important role in establishing the diagnosis and the most appropriate patient management. However, data are lacking regarding the use of preclinical molecular imaging techniques to assess osteomyelitis progression in experimental models. This study aimed to compare structural and molecular imaging to assess disease progression in a mouse model of implant-related bone and joint infections caused by Staphylococcus aureus. In SWISS mice, the right femur was implanted with a resorbable filament impregnated with S. aureus (infected group, = 10) or sterile culture medium (uninfected group, = 6). Eight animals (5 infected, 3 uninfected) were analyzed with magnetic resonance imaging (MRI) at 1, 2, and 3 weeks postintervention, and 8 mice were analyzed with [F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)-computed tomography (CT) at 48 h and at 1, 2, and 3 weeks postintervention. In infected animals, CT showed bone lesion progression, mainly in the distal epiphysis, although some uninfected animals presented evident bone sequestra at 3 weeks. MRI showed a lesion in the articular area that persisted for 3 weeks in infected animals. This lesion was smaller and less evident in the uninfected group. At 48 h postintervention, FDG-PET showed higher joint uptake in the infected group than in the uninfected group ( = 0.025). Over time, the difference between groups increased. These results indicate that FDG-PET imaging was much more sensitive than MRI and CT for differentiating between infection and inflammation at early stages. FDG-PET clearly distinguished between infection and postsurgical bone healing (in uninfected animals) from 48 h to 3 weeks after implantation. Our results encourage future investigations on the utility of the model for testing different therapeutic procedures for osteomyelitis.
骨髓炎是一种骨感染，伴有炎症过程。影像学在确定诊断和最合适的患者管理方面发挥着重要作用。然而，关于使用临床前分子成像技术来评估实验模型中的骨髓炎进展，数据尚缺乏。本研究旨在比较结构和分子成像以评估金黄色葡萄球菌引起的植入物相关骨和关节感染的小鼠模型中的疾病进展。在瑞士小鼠中，右股骨植入了一种可吸收的细丝，该细丝浸渍有金黄色葡萄球菌（感染组， = 10）或无菌培养基（未感染组， = 6）。8 只动物（5 只感染，3 只未感染）在干预后 1、2 和 3 周分别进行磁共振成像（MRI）分析，8 只动物在 48 h 和干预后 1、2 和 3 周分别进行 [F]氟脱氧葡萄糖（FDG）-正电子发射断层扫描（PET）-计算机断层扫描（CT）分析。在感染动物中，CT 显示骨病变进展，主要在远侧骨骺，尽管一些未感染动物在 3 周时出现明显的骨块。MRI 显示在关节区域存在病变，在感染动物中持续了 3 周。在未感染组中，该病变较小且不明显。在干预后 48 h，FDG-PET 显示感染组的关节摄取量高于未感染组（ = 0.025）。随着时间的推移，两组之间的差异增加。这些结果表明，与 MRI 和 CT 相比，FDG-PET 成像在早期区分感染和炎症更为敏感。FDG-PET 从植入后 48 h 到 3 周，清楚地区分了感染和手术后骨愈合（未感染动物）。我们的结果鼓励对该模型在测试不同骨髓炎治疗方法中的效用进行进一步研究。
