By Ricardo Alonso-Zaldivar

Associated Press

A lab company president called to testify before Congress in the salmonella outbreak investigation said Thursday that manufacturers "can't retest away a positive result."

Charles Deibel, whose labs conducted tests for Peanut Corp. of America, said that if 100 containers were tested and only one or two turned up salmonella, the company should "throw the whole lot out."

Federal health officials say Peanut Corp. shipped tainted peanut products from its Blakely, Ga., facility after retesting them and getting a negative result for salmonella.

Peanut butter, peanut paste and other goods from the plant are being blamed for an outbreak that has sickened more than 500 people, triggered a massive international recall and raised doubts about the food industry's safety practices.

Deibel said his company - Deibel Labs Inc. - did not conduct day-to-day testing for the Blakely plant, but was asked on occasion to carry out certain tests. He said the company has turned over bacterial cultures to federal investigators.

Deibel and the president of another lab, J. Leek Associates Inc., have been called to testify Feb. 11 before the House Energy and Commerce Committee. The Deibel firm has been in existence since the 1960s and has its main lab in Chicago.

Rep. Henry Waxman, D-Calif., chairman of the panel conducting a hearing into the outbreak, said the investigation shows "major gaps" in the nation's food safety system.

"I am extremely troubled by reports that the plant tested positive for salmonella numerous times but nothing was done to ensure that the product did not go on the market," Waxman said.

Peanut Corp., based in Lynchburg, Va., said in a statement it "categorically denies any allegations that the company sought favorable results from any lab in order to ship its products."

Deibel said his firm is still poring over records to determine what kind of testing was done, and at what times, for Peanut Corp.'s plant.

He said his lab tested some salmonella cultures that came from the J. Leek lab and identified the specific variety of the bacteria that was present. Those cultures have been turned over to investigators from the Food and Drug Administration and the Centers for Disease Control.

Darlene Cowart, president of the J. Leek lab, was not available Thursday.

Deibel his lab also tested samples of peanut products sent directly from the Blakely facility, but that he did not have the results of those tests available.

Salmonella can exist in a dormant state in products like peanut butter, isolated in pockets of a big batch. So experts say it's possible to get positive and negative results from the same batch.

"The benefit of using multiple labs is you increase your chances of finding it," said Deibel.

"Our recommendation to clients is that you can't retest away a positive result," he added. "We call it 'testing into compliance,' and that is frowned upon."

Meanwhile, the Army joined the peanut recall Thursday. It's removing some peanut butter items from warehouses in Europe.

In the civilian world, more than 430 kinds of cakes, cookies and other goods have been pulled off store shelves in what the FDA is calling one of the largest product recalls in memory. The Army's recall does not affect Meals-Ready-to-Eat, but another kind of military grub called Unitized Group Rations-A, which provide a complete 50-person meal.

Nationwide, at least eight people may have died of illnesses linked to the outbreak.

The recall covers peanut butter, peanut paste, peanut meal and granulated products, as well as all peanuts - dry and oil roasted - shipped from the factory. FDA officials could not quantify the amount of products being recalled.

Officials recommend that consumers check the FDA web site, which lists all the products being recalled. Consumers who find any such products in their cupboards should toss them away. If they're uncertain about eating a particular product, they should check it out first.