New research conducted in Israel suggests that the method that some bacteria, including Sallmonella, are enetering leafy greens is connected to light exposure, as reported today on an L.A. Times blog. 

The new study was published in the journal "Applied and Environmental Microbiology."  The findings, as reported by the L.A. Times:

Salmonella penetrates the lettuce leaf’s deeper surfaces by entering little pores called stomata. These are the pores plants use to obtain and release gases during photosynthesis–the vital process by which light energy is captured and turned into sugars. There are rather nasty pictures in the article of rod-like salmonella clustered all around these stomata, seemingly going down into them and thus into the inner parts of the leaf.

The infromation could prove useful in limiting bacteria’s access to leafy greens.  Such a step might help stem the tide of foodborne illness outbreaks tied to spinach, lettuce and other greens, involving pathogens like E. coli O157:H7, Salmonella, and Hepatitis A.