How common are Salmonella outbreaks on vegetable and fruit produce?
A recent census of produce outbreaks between 1996 and 2007 counted no fewer than 33 epidemics from Salmonella-contaminated fruits and vegetables. In five of them, tomatoes were the culprit. Cantaloupe melons and sprouted seeds, such as clover and alfalfa, were also common victims. Animal pathogens tend to infect only a limited range of plants. Are the strains different from the ones that come from undercooked chicken and raw eggs? Yes, according to Warriner, the strains that infect tomatoes and other plants differ from the strains that you find in dairy and poultry. His lab is currently investigating how the produce strains adapt to tomatoes. So far, he has discovered that the bacteria tend to “turn up” a gene involved in stress responses. The strain linked to the current outbreak, called “Saint Paul”, is rare, but not too different from the other tomato-infecting strains. “There’s nothing special about ‘Saint Paul’,” he says. Why are we seeing more outbreaks linked to vegetable and fr
