Washington: Germs like E. coli and Salmonella lurk in raw vegetables, where it might not be possible to remove them even with repeated washing, say US scientists.
These contaminated items could be a potent source of infection, according to the new study by Purdue University.
An E. coli strain was present in tissues of moong bean sprouts. Salmonella was present in peanut seedlings.
"The pathogens were in every major tissue, including the tissue that transports nutrients in plants," says study co-author Amanda Deering, the Journal of Food Protection and Food Research International reports.
Finding pathogens inside plants has been challenging because tests require slicing off pieces of the plants, which can move the bacteria from the outside to the inside or vice versa, say Deering and co-author Robert Pruitt.
"The results are often imprecise because the methods allow bacteria to move," says Pruitt, according to a University statement.
Cooking those foods to temperatures known to kill the pathogens would eliminate them from inner tissues, the researchers say.