FIG. 6.

Intestinal localization of bacteria in periods of low signal during biliary excretion. The mouse shown was infected with attenuated strain 2C(Δhly) and imaged as described in the legend of Fig. 4. After fasting for 6 h, the animal was then injected intraperitoneally with CCK8, and serial images were taken as described in the legend of Fig. 2. When a period of signal reduction occurred during the transit through the intestine, the mouse was sacrificed and the intestine was removed for ex vivo BLI. Images of the excised organ were then taken at a higher resolution (binning, 2 by 2) (B) and a higher signal-to-noise ratio (binning, 10 by 10) (C). A single reference image was used for the series. Focal signals in the excised intestine are designated with arrows. Quantification of the signals using regions of interest identical to those of Fig. 2 is shown in the bottom panel.