Researchers
have found that food-poisoning bacteria, Listeria monocytogenes, can hide
inside romaine lettuce.
That
means that surface cleansing and disinfecting procedures won’t kill the nasty bacteria
that is particularly risky for the very young, the very old and people with
compromised immune systems.
A team
at Purdue University in Indianna, led by Amanda Deering, clinical assistant professor
in the Department of Food Science, showed that the
bacteria could live within lettuce in every stage of the plant growth process,
residing inside the plant tissue.
L. monocytogenes can gain entry into the plant
through cracked seed coats, small tears in root tissue during germination and
damaged plant tissue. The researchers found that exposing lettuce to the
bacteria could lead to infection of plant tissue in as little as 30 minutes.
“Knowing
this can happen, we need to keep it on our radar as we continue to follow good
agricultural practices,” Deering said.
L. monocytogenes can also cross the placental barrier
in pregnant women, which can trigger a miscarriage.
“For
immune-compromised consumers, it’s important to remember, that canned or cooked
produce is better,” Deering said.
This
bacteria thrives in cool temperatures which are sometimes used to fight other
food-poisoning strains of bacteria. Heat kills them all.
