Salmonella and other foodpoisoning outbreaks everywhere right now.  Cantaloupes and listeria, produce and E. coli O157:H7, chicken livers and Salmonella, Salmonella and pine nuts.  It has been a studied question for years now whether produce items (like lettuce, spinach, and other leafy greens) actually uptake the bacteria through the root system and run into the vasculature of the leaves themselves.  A scary thought that would mean effectively no way for the processor or consumer to rid the plant (i.e. your salad) of bacteria. 

The theory seemed to have fallen out of favor, as far as we food safety lawyers could gather from the literature.  But the University of Florida recently announced the results of an interesting study that appears to reinvigorate the debate:

Plant pathologist Ariena van Bruggen, a professor in UF’s Institute of Food and Agricultural Sciences, published a paper today in the online journal PLoS One, with research findings that show — for the first time — that Salmonella can enter tomato plants through intact leaves, travel through the plant and end up in the fruit itself.

But she says she can’t stress enough that it isn’t at all easy for it to happen, even in the lab, and would be unlikely under field conditions.

“The message is that yes, (Salmonella) can be internalized in tomato, but it’s rare — the chance is so low,” she said. “I would tell consumers not to worry too much.”

Sounds like the reality is that it would take a significant level of contamination, and just the right conditions, for bacteria to be internalized in a tomato plant.  Good news for produce growers and consumers alike.  Then again, we’ve seen “just the right conditions” before occur in a food safety catastrophe–most recently, right now, with cantaloupes that have killed 30.