Lettuce,spinach and most recently tomatoes have been implicated in food borne disease outbreaks in North America.Food borne illnesses can be serious or even fatal,and result in loss of consumer trust which has repercussions for the market and the farmer.Produce may be contaminated due to inadequately composted manure,contaminated water,or poor hygiene during handling.The potential presence of human pathogens is usually determined by employing a test for the common intestinal bacterium Escherichia coli.However,there are some conditions where its suitability as an indicator may be questioned as it could be less viable than some more robust pathogens.Enterococcus faecalis has been suggested as another potential indicator.