Fig. 1.
Monitoring transmission of the gastrointestinal pathogen Citrobacter rodentium through the faecal–oral route using BPI. Mice were exposed to infectious C. rodentium ICC180 in the cage environment and transmission and infection dynamics were determined by BPI. Images were acquired using an IVIS system (Caliper Life Sciences) with an integration time of 1 min and are displayed as pseudocolour images of peak bioluminescence, with variations in colour representing light intensity at a given location. Red represents the most intense light emission, while blue corresponds to the weakest signal. The colour bar indicates relative signal intensity (as photons s−1 cm−2 sr−1). The same four mice were imaged 24 h (top panel) and 48 h (bottom panel) after introduction into the contaminated cage.