Figure 3.

Transgenic BALB/c mice expressing human transferrin were infected by intraperitoneal injection of 1.5 × 10⁷ CFU of the bioluminescent N. meningitidis strain 24198LUX. A 2D CT Scan coupled with bioluminescence imaging was performed (A and B). Images depict CT scan acquisitions overlaid with colour representations of luminescence intensity, measured in total photons/sec and indicated on the scales. The CT scan was performed from a ventral (A) and from a dorsal view (B). The heart is highlighted by (#) and the kidneys are highlighted by (*) in the image without bioluminescence. In a distinct experiment, the analysis for bioluminescence was performed using an IVIS 100 system (Xenogen Corp., Alameda, CA, USA). Organs were withdrawn and are indicated in the image without bioluminescence (C). Bioluminescent imaging of withdrawn organs showed a high number of bacteria in the kidneys, the liver, the spleen and the brain (D). When focusing on the brain (E), the signal was diffuse as it is shown on the dorsal view (E upper part) and localized within the ventricular space when both hemispheres were imaged (E lower part).