Guilty Pleas in Outbreak of Listeria DENVER - Two Colorado farmers whose listeria-contaminated cantaloupes killed 33 people pleaded guilty on Tuesday to federal criminal charges stemming from one of the deadliest outbreaks of food-borne illness in the United States. Prosecutors last month charged the brothers, the former owners of Colorado-based Jensen Farms, with six counts each of introducing adulterated food into interstate commerce tied to shipping tainted melons to markets. In May 2011, prosecutors said, the Jensens began washing the farm's cantaloupes with devices used to clean potatoes and failed to use a chlorine spray feature that kills deadly bacteria. Both men pleaded guilty in Federal District Court in Denver. They face sentences of up to six years in federal prison and fines of up to $1.5 million for their conviction on all six counts. The brothers initially pleaded not guilty to the charges, but later agreed to change their plea in a deal with prosecutors. "The defendants have now admitted that they failed to protect the public from deadly bacteria on their cantaloupe, in violation of the law and critical F.D.A. requirements," the United States attorney for Denver, John F. Walsh, said in a statement. Forrest Lewis, a lawyer for Eric Jensen, said the brothers thought the cleaning operation they used "was safe and inspected and adequate." In addition to the deaths, the listeria outbreak led to the hospitalization of 147 people across 28 states, the authorities said. One woman suffered a miscarriage. The Jensens filed for bankruptcy in 2012 and suspended farming after lawsuits were filed by people sickened or whose family members died from listeria infections. Last week, the Jensens sued a food safety audit firm, the Primus Group, which they said approved the cleaning operation. The brothers are to be sentenced in January.