FIOCRUZ, Instituto de Tecnologia em Imunobiológicos, Rio de Janeiro, Brazil.
Fundação Oswaldo Cruz, Instituto de Tecnologia emImunobiológicos-BioManguinhos Fiocruz, Rio de Janeiro, Brazil.
Lab Anim. 2024 Jun;58(3):231-239. doi: 10.1177/00236772231209790. Epub 2024 Mar 9.
nasal carriage is considered a risk factor for infections, and the development of nasal decolonization strategies is highly relevant. Despite they are not naturally colonized by , mice are a good model for nasal colonization. Murine models are easy to manipulate, and inter-laboratory reproducibility makes them suitable for nasal colonization studies. Strategies using bioluminescent bacteria allow for the monitoring of infection over time without the need to sacrifice animals for bacterial quantification. In this study, we evaluated nasal colonization in three mouse strains (BALB/c, C57BL/6, and Swiss Webster) using a bioluminescent strain (SAP231). In vitro, a visible Bioluminescent Signal Emission (BLSE) was observed until 10 bacteria and detected by IVIS® imaging system up to 10 cells. Animals were inoculated with one or two doses of approximately 10 colony-forming units (CFU) of SAP231. Swiss Webster mice showed the longest colonization time, with some animals presenting BLSE for up to 140 h. In addition, BLSE was higher in this strain. BALB/c and C57BL/6 strains showed consistent BLSE results for 48 h. BLSE intensity was higher in Swiss Webster inoculated with both doses. Three different positions for image capture were evaluated, with better results for the lateral and ventrodorsal positions. After the loss of BLSE, bacterial quantification was performed, and Swiss Webster mice presented more bacteria in the nasal cavity (approximately 10 CFU) than the other strains. Our results demonstrate that bioluminescent allow monitoring of nasal colonization and estimation of the bacterial burden present in live animals until 48 h.
鼻腔携带被认为是感染的危险因素，因此开发鼻腔去定植策略具有重要意义。尽管 不会自然定植于鼻腔，但小鼠是鼻腔定植的良好模型。小鼠模型易于操作，且实验室间的可重复性使其适合用于鼻腔定植研究。使用生物发光细菌的策略可在无需对动物进行细菌定量以牺牲动物的前提下，实时监测感染情况。在这项研究中，我们使用生物发光菌株 SAP231 评估了三种小鼠品系（BALB/c、C57BL/6 和 Swiss Webster）的 鼻腔定植情况。在体外，我们观察到直到 10 个细菌时出现可见的生物发光信号发射（BLSE），并通过 IVIS®成像系统检测到高达 10 个细胞。动物接受了大约 10 个集落形成单位（CFU）SAP231 的一次或两次剂量接种。Swiss Webster 小鼠表现出最长的定植时间，有些动物的 BLSE 持续时间长达 140 小时。此外，该品系的 BLSE 更高。BALB/c 和 C57BL/6 品系在 48 小时内显示出一致的 BLSE 结果。两种剂量接种的 Swiss Webster 小鼠的 BLSE 强度更高。我们评估了三种不同的图像采集位置，侧面和背腹位置的结果更好。在 BLSE 消失后，进行了细菌定量，Swiss Webster 小鼠鼻腔中的细菌数量（约 10 CFU）高于其他品系。我们的结果表明，生物发光 可用于监测鼻腔定植，并估计活体动物中存在的细菌负荷，直至 48 小时。
