Vegetables most commonly contaminated:
Sprouts
Spinach
Tomatoes
Lettuce
Cucumbers
Most common food-borne pathogens:
E. coli
Campylobacter
Salmonella
Sources of contamination:
E. coli – fecal matter (runoff, animals, contaminated water, unwashed hands)
Campylobacter – possibly more than 50 percent of chickens are infected, in addition to wild birds and cows (spread through direct contact or contaminated water)
Salmonella – naturally occurs in the intestines of many animals (unhygienic kitchen conditions, improperly thawed fowl, standing water)
Sources: Humboldt County Department of Health and Human Services, U.S Food and Drug Administration.
This article appears in How Does Your Garden Grow?.