Updated

Tests have confirmed that peanut butter made from peanuts processed at a Texas plant contains the same strain of salmonella blamed for sickening hundreds in a national outbreak, federal officials said Tuesday.

The test results offer new evidence that the outbreak attributed to a peanut plant in Georgia may have more than one source. Both the Texas plant and the Georgia plant were operated by Peanut Corp. of America, which filed for bankruptcy amid fallout from the outbreak that has sickened more than 600 and may have contributed to nine deaths. The outbreak has also prompted one of the largest food recalls in U.S. history.

Meanwhile, federal inspectors are taking a closer look at Peanut Corp.'s plant in Virginia, where records obtained by The Associated Press on Tuesday show state inspectors repeatedly found health violations.

The link between the outbreak strain and the Texas plant surfaced after health officials in Colorado traced salmonella cases there to peanut butter sold by the Vitamin Cottage grocery chain. The peanuts used in the Vitamin Cottage peanut butter came from Peanut Corp.'s plant in Plainview, Texas, the natural foods chain has said.

An opened container of Vitamin Cottage peanut butter tested positive for the outbreak strain, which came from a Colorado resident who got sick, company vice president Heather Isely has said. Earlier, the same strain of salmonella bacteria was detected in containers of peanut butter that had been produced at a Peanut Corp. plant in Blakely, Ga.

U.S. Food and Drug Administration spokeswoman Stephanie Kwisnek said two samples of Vitamin Cottage peanut butter from two different consumers tested positive for the outbreak strain, but it was not clear how many containers were involved.

It's possible the Vitamin Cottage peanut butter was contaminated after it was opened, health officials noted. But the latest test results raise questions about how many of the outbreak illnesses — which have been attributed to the Blakely plant — came from other production facilities.

"Because of the public health risk posed by positive findings of salmonella associated with the outbreak strain at PCA's plant in Blakely, Ga., the FDA expanded its scope of inspections to include other PCA plants," said FDA spokeswoman Stephanie Kwisnek.

Peanut Corp., the Lynchburg, Va.-based food processor, has filed for Chapter 7 bankruptcy and federal authorities have launched a criminal investigation into allegations the company knowingly shipped tainted food. Peanut Corp. also faces a growing number of federal lawsuits seeking millions of dollars of damages from victims of the outbreak.

In Virginia, tests for salmonella have come back negative. But inspection reports revealed evidence of rodents and other unsanitary conditions at the Peanut Corp. plant in Suffolk. State inspectors repeatedly found evidence of rodents at the plant since Peanut Corp. bought it in 2000, according to inspection reports.

As recently as October, a Virginia inspector found "an accumulation of black, green and yellow mold" on blanched peanuts and 43 containers each holding 2,000-pounds of peanuts. The plant manager told the inspector after the discovery that those peanuts would be destroyed if not used for animal feed and oil stock.

Virginia Agriculture Department spokeswoman Elaine Lidholm has called those findings minor violations.