Figure 1.

C. elegans showing internalized salmonella bacteria. A fluorescent microscopy image of the free-living helminth Ceanorhabitis elegans that had fed, for 36 hours, on a lawn of Salmonella Typhimurium that are expressing green fluorescent protein (GFP), so that the bacteria emitted phosphorescent light. Bacteria were externally removed from the C. elegans and can be clearly seen in the intestine.