Non-Washable Listeria in Cantaloupes

No amount of washing, scrubbing, bleaching or peeling would have cleaned cantaloupes contaminated by Jensen Farms' packing practices enough to remove listeria bacteria that has sickened at least 123 people and killed 25 in the deadliest outbreak in a quarter-century.

"There's nothing consumers could have done," said Dr. Doug Powell, a professor of food safety at Kansas State University in Manhattan, Kan.

Federal Food and Drug Administration officials reported Wednesday that standing pools of water, inaccessible drains, hard-to-clean equipment and failure to cool cantaloupes fresh from the field before placing them in cold storage all likely contributed to the growth and spread of four strains of listeria bacteria at the Jensen Farms packing site in Granada, Colo.

In addition, listeria could have been introduced into the packing center from sporadic bacteria in the field or from a dump truck that hauled culled cantaloupe back and forth to a cattle yard and then parked next to where the whole melons were being processed. Cattle are known reservoirs for listeria.

The cold, moist environment maintained over time is exactly what listeria needs to thrive, said Dr. Mike Osterholm, director of the Center for Infectious Disease Research and Policy and a food safety expert at the University of Minnesota. 

Source: msnbc.com