More than 100 people have fallen ill in recent days and one died after eating raw spinach contaminated with the O157:H7 strain of E. coli, according to FDA officials. A second death, of a person in Ohio, was being studied to see if it also was linked to the outbreak.

The CDC has now linked 114 cases of E. coli poisoning in 21 states to raw spinach. The states with the largest number of cases were Wisconsin with 32, Utah with 15 and Ohio with 10, according to The Western Star.

Potentially deadly E. coli bacteria can contaminate edible parts of plants like spinach and lettuce through water absorbed by the plants’ roots, scientists said Monday as federal officials reported that a new outbreak of the bacteria continues to spread.

Scientists at Rutgers University reported four years ago that they had shown that quantities of the bacteria sufficient to cause disease can be present in – rather than on – the plants’ leaves.

"I am concerned from the findings that we have," said Karl Matthews, a microbiologist. "You can’t wash the organism away from the crop. Even if it’s washed several times, you’re not actually washing away the organism."

After growing lettuce in soil that had been deliberately inoculated with E. coli O157:H7, Matthews washed the leaves in bleach but still found the bacteria inside the plant tissues.

The scientists’ findings means that no amount of rinsing or careful handling can keep the E. coli out of salads and other foods in which raw vegetables are used if the pathogen is in, rather than on, plant leaves. It also poses new challenges for farmers seeking to ensure that their crops remain free of the contaminant.