I know listeria by its connection with hot dogs and deli meats. Never heard it linked to produce. An unusual feature is that it grows well in the cold temperatures that impede the growth of other organisms.
As usual, Bill Marler has been furiously updating. This pronouncement from his blog this morning deserves attention:
"And, for the argument that the sick and dead should have washed away the listeria, the FDA advises consumers not to eat the recalled cantaloupes and to throw them away. In Fact, the FDA says:Do not try to wash the harmful bacteria off the cantaloupe as contamination may be both on the inside and outside of the cantaloupe. Cutting, slicing and dicing may also transfer harmful bacteria from the fruit’s surface to the fruit’s flesh."