msnbc reports now that federal investigators have identified dirty equipment, faulty sanitation and bad storage practices at a Colorado farm as the likely cause of a cantaloupe listeria outbreak that has killed 25 people, top U.S. food safety experts say there’s one actor in this deadly drama that shouldn’t be blamed: The consumer.

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

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.

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.

The bacteria clearly contaminated a huge proportion of the more than 310,000 cases of cantaloupe — between 1.5 million and 4.5 million fruit — that were recalled by Jensen Farms in mid-September, said Powell.

"Given that 25 people are dead, this was a massive contamination to have that impact," he said.

It’s not clear whether people were infected by bacteria that clung to the fruit’s porous, bumpy rind, whether the germs somehow migrated into the flesh of the fruit, or whether people spread contamination through the fruit by slicing it with a knife, Powell said. Good hygiene and food safety practices can lessen the chance of infection, but the contamination shouldn’t be there in the first place.

"The idea that this is the consumer’s responsibility is just nonsense," he said. "What’s missing is any verification that individual farmers are doing what they’re supposed to be doing."

"Don’t rely on paperwork if your brand relies on selling safe food," Powell said. "Any commodity is only as good as its worst grower."