Federal officials confirmed Monday they found traces of salmonella in a central California pistachio processing plant that sparked a nationwide recall of the nut.
The Food and Drug Administration said state and federal inspectors discovered the bacteria in "critical areas" at Setton Pistachio of Terra Bella, Inc., the second-largest pistachio processor in the nation.
FDA officials also said they found places at the facility where raw and roasted nuts could have become cross-contaminated with salmonella.
Setton Pistachio, which sells its nuts to Kraft Foods Inc. and 35 other wholesalers across the country, temporarily shut down after voluntarily recalling more than 2 million pounds of nuts last week.
The company expanded its recall on Monday to include all raw and roasted pistachios from its 2008 crop. A company spokeswoman did not immediately return messages seeking further details.
"The company is working closely with the FDA on this matter and is cooperating fully," Setton spokeswoman Fabia D'Arienzo said in a statement. "Setton Pistachio of Terra Bella, Inc. is committed to quality products and consumer safety, and is taking aggressive action to prevent the need for any future recalls."
Federal regulators say consumers should avoid eating pistachios or foods made with the nuts until they can determine that they don't contain any nuts that Setton has recalled. The FDA on Monday also advised wholesalers, retailers, and operators of restaurants and food service establishments against selling or serving any pistachios or pistachio products until they can figure out whether they came from Setton.
No illnesses from consumers eating tainted pistachios have been reported.
The contamination was discovered by a Kraft manufacturer in Illinois, where workers doing routine testing found the bacteria in roasted pistachios about to go into trail mix. Officials traced the source back to the Terra Bella plant that supplied the nuts.
Pistachios are used in everything from ice cream to cake mixes, and the FDA believes more recalls are imminent.
Salmonella, the most common cause of food-borne illness, causes diarrhea, fever and cramping. Most people recover, but the infection can be life-threatening for children, the elderly and people with weakened immune systems.
Roasting is supposed to kill the bacteria in nuts. But problems can occur if the roasting is not done correctly or if roasted nuts are re-contaminated.