Lettuce leaf infected with Escherichia coli bacteria, which congregate at the leaf stomata (respiration orifices). Infection of leaf vegetables with toxigenic E. coli poses a severe health hazard, because these vegetables are consumed raw (without any heat treatment) and the pathogens are well adapted to human intestines. A pair of SEM micrographs was taken at a 10 degree difference and the micrographs have been combined into a red-and-green anaglyph (stereo picture). The 3-dimensional nature of the micrograph is apparent when viewed through a pair of red and green glasses. Enhanced SEM. Image width: 17.2 micrometers; magnification: 5814x if the image is printed 10 cm wide.